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Summer Cuttings.

Thursday, August 18th, 2011

Aside from all their other many distinctions and similarities, gardeners tend to fall into one of two camps: those who propagate and those who don’t. At the ago of around 10, and with able parental assistance, I built myself a little heated propagator, fuelled by a single light bulb. Into this tiny hot-house I put all manner of tropical and house-plant cuttings, those plants being my primary interest at that age. The ease with which most of my experimental subjects sprouted roots and became new, independent living plants astonished and delighted me, and from there on I was pretty much hooked.

There’s no greater encouragement than success, and I suspect that, much like myself, most gardeners who have tried and succeeded in creating new plants from old are equally hooked and continue to dabble in the art of propagation for the rest of their gardening days. Those who haven’t yet dipped their toes in the water are missing a treat. After all, what could be more satisfying than producing new plants for yourself or for friends, for free, particularly when doing so requires very little time and no particular green-fingered skill.

Newly rooted Salvia cuttings - just 4 weeks after being taken.

There are a variety of types of cuttings and times of year in which to make them, from softwood – made from the new growth of spring – to fully matured hardwood – often made over winter. Right now, though, is the perfect time of year for success with two different cutting types, taken from two different plant types. The first of these are semi-ripe cuttings of hardwood shrubs, both deciduous and evergreen. The second are soft growth cuttings made from tender perennials  such as Verbena, Pelargonium, Argyranthemum, Fuchsia, Salvias etc. Despite the obvious differences in the types of plants and the cutting material involved, the techniques for both are the essentially the same, dictated, as they are, more by the time of year rather than the type of plant involved.

Once you’ve decided upon a plant that you want to propagate the first course of action is to assemble your materials, very simple though they are. In it’s most basic form, all that you will need are:

1) Sterilized small plastic plant pots (boiling water will do the trick perfectly well)

2) Clear plastic bags (freezer bags etc.) that fit snugly over the tops of the pots and/or elastic bands to keep them in place

3) Potting compost (more of which anon)

4) Labels

5) Hormone rooting powder or liquid (optional, rather than essential)

6) Sharp secateurs (essential, rather than optional)

Semi-ripe summer cuttings are the ideal way to propagate many woody shrubs.

You’re now ready to take the cuttings. On shrubby plants choose growth that has been made earlier the same year, which will be noticeably different in colour and firmness than the previous years’ growth. The shoots should be pest and disease free and also non-flowering. Aim to make cuttings that are approx. 5 to 10 cm in length, making a straight, clean cut just below a pair of leaves or growth buds – it’s often easier to take somewhat longer shoots and then re-trim them ready for use later. Place the cuttings into a moistened plastic bag immediately, and keep in the shade, to help prevent water-loss and the subsequent wilting which can be terminal for a new cutting.

Make the cut just beneath a leaf joint.

Once back at your potting area you can further trim and prepare the cuttings, leaving just one or two pairs of leaves at the growing tip, and removing all of the lower leaves, most particularly any that would be in or upon the compost once the cutting is potted up. This reduces water loss as well as helping to minimise the risk of rotting and fungal infection. The leaf joints of plants are loaded with growth hormones, but many cuttings tend to root better and more quickly if the cut end is dipped into rooting hormone power or liquid, although this artificial hormone boost is far from crucial.

Dipping a newly trimmed Perlagonium cutting into hormone rooting powder.

The next step is the compost mixture, which, for cuttings, needs to fulfil two somewhat opposing roles. Obviously a cutting, until rooted, is unable to draw water up in the way that a fully formed plant can, so composts need to be sufficiently moisture-retentive to prevent drying out and death. At the same time the compost much be very free-draining since any hint of water-logging will likely spell rot and the rapid advance of fungal infection. The nutrient level of the compost is largely irrelevant since cuttings do not draw food from their compost until they are well rooted. With all of this in mind a good cuttings compost should be about 50% sharp, coarse, large-particle drainage material – horticultural grit or perlite, definitely NOT sand – and 50%  potting compost, preferably soil/loam or bark based.

Parent plant and new cuttings in a sharply draining grit/loam mix.

Fill one of your pots with the compost mixture, firming down well and levelling off leaving a few cm at the top of the pot to allow for eventual watering. You can then insert several cuttings around the edge of the pot (this being where the drainage is best) making sure, as much as possible, that they do not touch one another and than none of their leaves touch the compost surface. In the case of cuttings from plants with very large leaves it is often best to reduce the size of each individual leaf so that they fit more comfortably into their pot. Cuttings root best when in company, so by all means place as many as possible into each pot. Then label and water well, making sure than the water drains freely out of the bottom of the pot.

Hebe cuttings being inserted around the edge of their pot.

Then pop one of the plastic bags over the pot, holding securely with an elastic band if neccessary. It’s essential that the bag is airtight in order to maintain close to 100% humidity within. If the bag is loose or ill-fitting then the cuttings will rapidly dry out and are almost certain to fail. Further options are the use of a propagator – a commercial variant of my childhood heated cuttings frame – or an under-pot heating pad, both of which can speed up the rooting process. The pots should then be placed in good light place, but kept out of direct sunlight until they have rooted.

Rhododendron cuttings, trimmed to size and firmly sealed into their zip-lock plastic bag.

From there it’s merely a question of checking that the moisture level is maintained – the bag should ideally be permanently “fogged” inside – and removing and fallen or aborted leaves ASAP. The aim of summer cuttings is to produce new young plants for the following growing season. Some subjects will root easily and quickly, within a few weeks, but others can take several months. Look for the presence of young roots appearing at the base of the pot, and for growth appearing on the cutting itself rather than being tempted to dig around in the pot to see what’s going on. Once they have rooted then you can punch a few holes in the bag to let the cuttings acclimatise to the lower humidly outside and eventually remove the bag and pot the cuttings up individually. Again, with rapid-rooting varieties of plant you’ll be able to get them to this stage before the end of the growing season, but slower rooting cuttings should be left to go dormant and can then be potted up individually the following spring.

A fig cutting, successfully rooted and now individually potted up.


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Superb Spindles.

Thursday, August 11th, 2011

In one of last months’ blogs I mentioned what a remarkably good year it is proving to be for fruit and seeds, with the warm, dry spring allowing maximum pollination, followed by a wet-ish summer when the fruits need moisture in order to swell and ripen. The Rowans – Sorbus species – undoubtedly lead the charge in mid-summer, but in terms of wow-factor, and as summer moves to it’s conclusion, the Rowans are now being eclipsed by an altogether less well-known and less celebrated group of plants – the Spindles.

Euonymus grandiflorus fruit capsules.

Spindles are from the genus Euonymus, well-known to most gardeners as the home of the very widely grown and bomb-proof (if rather innocuous) evergreen ground-cover plant E. fortunei and the equally indestructible shrubby E. japonicus, widely planted as hedging. I would guess that for many those two plants are both the beginning and the end of their experience of Euonymus, which is something of a minor tragedy, as this fascinating genus contains over 175 species, many of which are exceedingly ornamental. Spread across all of the continents (barring Antarctica, obviously!) these highly successful plants have evolved and diversified into small trees, shrubs, climbers and creepers, such as good old E. fortunei.

Euonymus planipes with semi-ripe, unopened fruit.

By far the majority of their number, however, are medium-to-large-growing shrubs. This band includes our native species, Euonymus europaeus, a deciduous shrub or small tree widespread across much of Europe and into Asia minor, and commonly seen forming part of the living tapestry of ancient hedgerows and woodlands. The wood of E. europaeus is unusually hard and was traditionally used to make the spindles used for the spinning of wool, flax and hemp, a utilitarian purpose which has lent the common name “Spindle” not just to our own species, but also to all of it’s shrubby relatives.

Euonymus cornutus var.quiquecornutus - this rare Chinese species has wonderfully "horned" fruits.

Throughout the early growing season the Spindles quietly get on with the business of growing, rarely drawing the gardeners attention. Their flowers are extremely curious and rather fascinating, but they are also absolutely tiny and are generally coloured in the green/brown regions of the colour spectrum. The casual observer might not even notice that a Spindle was flowering, even when at it’s peak. Those miniature blooms are popular with bees and hoverflies, which is always a plus in any garden, but it’s what happens next that holds the key to the Spindles splendour.

Euonymus europaeus in flower.

Following pollination the flower ovary expands considerably to form a fruit, and by mid August the fruits of the earliest of the Spindle species are beginning to ripen and burst open in the most spectacular fashion. Although their shapes vary somewhat across the species all Spindle fruits are heavily lobed, commonly likened to spinning tops or jesters hats – these are plants of great character, to be sure. Those fruits are also vividly coloured – typically bright pink or red externally, opening to reveal tangerine-orange coloured seeds. As they ripen the seeds, rather than simply being shed onto the ground, are held for several weeks  to dangle on delicate threads that extend from their cases. In a good season – and 2011 is about as good as any I can remember – the overall effect of a Spindle in full fruit is quite wonderful.

Euonymus hamiltonianus 'Winter Glory', with it's heavy clusters of fruit.

The Spindles have another trick up their woody sleeves too, and as the chills of autumn arrive the leaves of many of the deciduous species start to turn to a dazzling array of colours from deep black-ish plum-purple, through every shade of yellow, orange and red and, in some cases, bright pink, all forming a backdrop to those fruits that are often retained well into winter.

An individula fruit of E. europaeus 'Red Cascade'.

In order to produce a good fruit set two or more individuals of the same species need to be grown together. Even then some Spindles are showier than others and both fruit set and particularly autumn foliage colour will vary greatly from year to year, dependant, as they both are, on the weather. Our own native E. europaeus, one of the largest growing species, is no slouch, and bears an abundance of fuchsia-pink seed capsules, followed by bright scarlet leaf colour. The best form for use in gardens is undoubtedly ‘Red Cascade’ which couples abundant fruit set with much more reliable autumn colour. E. europaeus f. albus is a variant with porcelain white fruit capsules, and the two are particularly effective when panted together, also forming pollination partners to ensure good fruit set.

Euonymus europaeus albus.

Euonymus hamiltonianus is the next most widely grown and distributed species, and many forms have now been selected and named. The fruits ripen much later, well into autumn as a rule, and mature to pink, whilst the large, glossy leaves fade to delicate shades of apricot, yellow and coral.

E. alatus, with it's full-on autumn effect.

E. alatus is very widely grown in the USA where it is a mainstay of some municipal plantings – not exactly a recommendation, perhaps – and is also freely available to gardeners here. Plants are compact, rounded and slow-growing, forming a tangled web of branches that bear wide, corky “wings” that are pretty attractive over winter. The fruits are small and red-purple, but the autumn leaf colour is vibrant, crimson-pink.

Euonymus latifolius.

E. latifolius and E. planipes are close relatives of one another, the former from Europe, the latter native to Japan. They are both readily cultivated and each produce large scarlet fruit and brilliant autumn foliage – highly recommended.

Euonymus myrianthus.

Not all of the Spindles are deciduous, and some of the most beautiful are evergreens native to China. E. myrianthus was a species that I first encountered as a teenager and, indeed, the one that awoke my enthusiasm for the Spindles in general. That particular plant was growing, as it still does, in the National Trust garden at Killerton, here in Devon, and I spent much time being fascinated by it’s deep golden fruits as well as admiring the tropical-lushness of the long, glossy leaves. E. myrianthus is a little tender in the garden, but it’s relative E. grandiflorus, is much tougher with large leaves that can remain evergreen in mild winters, or else age to deep burgundy and are slowly shed over the winter – a great foil for the beautiful, shell-pink fruits.

Euonymus grandiflorus, with not-yet-opened seed capsules.

The recent rise in interest in the Spindles, coupled with a mass of plant-hunting expeditions to Asia, has brought many new species into British cultivation and popularised others that have long been on the horticultural back-burner.  A few of my favourites are the exceedingly elegant E. bungeanus, with delicate, arching branches, slender, drooping leaves and blush-pink fruits; the wonderfully named E. cornutus var. quinquecornutus, a narrow-leafed semi-evergreen with perhaps the most dramatic fruits of all the Spindles; and E. americanus, with fruits that look just like little pink sea-urchins.

Commonly known (in the US) as the Strawberry Bush, Euonymus americanus is irresistible in fruit.

Aside from the few somewhat tender species, the Spindles are an adaptable and easily cultivated lot. We grow them successfully here on our mildly acidic river soil, but they will thrive on most soils, and do particularly well on chalk, making them amongst the most valuable of all shrubs for those somewhat difficult alkaline gardens. They are not large or difficult to accommodate in even small sites, and provided they receive a reasonable amount of sun they will reward you year after year with their impressive displays.

The delicate autumn colours and cascading foliage of E. bungeanus


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Blueberries for Everyone.

Wednesday, August 3rd, 2011

Blueberrys are definitely one of the “it” foods of the moment. Loaded, as they are, with both vitamin C and a multitude of other antioxidants, their virtues are regularly extolled in the press and their status as a so-called “super-food” has seen supermarket demand for these little fruits soar over the last decade. Whilst every fruitier and market worth their salt will now supply pricey little punnets of blueberries, both in and out of season, these plants are very easy to grow here in the UK, and within a few years a healthy bush can produce a huge crop of fruit on an annual basis.

Vaccinium corymbosum 'Bluecrop' - the single most widely planted variety of blueberry.

Blueberries are the fruit of Vaccinium corymbosum (the Highbush Blueberry) and a handful of closely related species including Vaccinium pensylvanicum (the Lowbush Blueberry).  These various species have been endlessly inter-bred and selected from over many generations with the aim of producing the best and most reliable fruiting forms. There are now literally hundreds of named varieties of Blueberry, and the precise botanical make-up of each is lost with amongst the endless crossing and back-crossing undertaken by their breeders. Still it’s fair to say that V. corymbosum is very much the backbone of  what we think of as the modern Blueberry, and the wild species is instantly recognisable as the parent of the little dusky blue fruits that are now so well known.

Vaccinium corymbosum forms a small, freely branching shrub.

Vaccinium corymbosum grows wild in eastern North America from Nova Scotia in Canada to Florida in the south. This huge and obviously very variable geographic range accounts for the diversity of the wild plants and also the way in which the many variants have been split away and named as separate species.  The plants typically grow as an understory shrub beneath Pines and Cedars where they thrive in dappled shade.

Vaccinium 'Elliot' is a vigorous, upright variety with small-ish fruit.

Vaccinium, the genus, is a part of the ericaceae, (named after Erica, the heathers) along with the likes of Arbutus, Rhododendron and Pieris, and, from a gardeners perspective, they are typical ericaceous, or acid-loving plants. In cultivation, therefore, an ideal garden soil will be one that favours others of their acid-loving relatives – moist but open and free-draining, peat, leafmould or river silt based. Blueberries are more tolerant of clay-based soils than many ericaceous plants, and providing soils are at least neutral in pH then the plants can be grown successfully in normal garden soil. Like all ericaceous plants Vaccinium have very fine, fibrous and shallow roots that are not very extensive in their spread and tend to concentrate in the upper 20 or 30 cm of soil. This makes the Blueberrys ideal subjects for growing in containers too, which allows the plants to be easily accomodated in any garden, even ones where the soil is not suitable for ericaceous plants.

Vaccinium corymbosum flowers - very typical of Ericaceae, and much like an enlarged Erica (Heather) flower.

Vaccinium corymbosum is a small, occasionally medium-sized shrub , that rarely exceeds 1.8metres in height or spread, and, in it’s smaller varieties, no more than half that. This compact nature further lends the plants to container growth, but also means that they can easily be fitted in around and between other, larger garden plants. We grow them extensively all across the lower half of the garden here in North Devon and they make really excellent in-fill plants, nestled under trees and various other North American shrubs.

Vaccinium 'Sunshine Blue' - one of the evergreen Blueberry varieties, and a dwarf plant that only reaches 60-90cm.

Although there are a few evergreen Blueberry varieties the vast majority are deciduous. The shrubs break their winter dormancy in early Spring and rapidly open their clusters of flowers, which closely resemble those of other members of the ericaceae, being essentially small and bell-shaped in shades of cream and sometimes rose-pink. The flowers are also lightly fragrant with the perfume most frequently likened to that of cowslips. Although they couldn’t exactly be called showy in bloom, the combination of the pretty, delicate hanging little-lanterns and their scent is certainly very appealing and they make a pleasing addition to any spring garden.

Vaccinium corymbosum 'Nui' - an early ripening variety selected in New Zealand that has attractive deep pink flowers.

Access to the nectar within the flowers is quite difficult for many potential pollinators and so the flowers are pollinated exclusively by bees, and species of solitary bees (rather than honey-bees) in particular. As the season progresses the leaves emerge and are fully unfurled by the end of Spring, by which time the flowers drop and any fruit that has been set starts to develop. The berries swell and ripen over a period of six to eight weeks, depending on the variety, and gradually change from green through red to blue or blue-black, with a whitish powdery bloom at maturity.

New, green berries starting to swell but a month or more from ripening.

The precise pattern and timing of ripening is very dependent on the weather, and cold, damp summers lead to slow and erratic ripening, whereas long periods of unbroken sunshine will bring the fruit to maturity much more rapidly. Similarly those fruits that are facing directly into the sun, or are positioned at the top of the bush will ripen more quickly. Generally, though, the bushes produce a useful succession of ripened fruit over a period of several weeks throughout late summer. Bearing this in mind (and despite their wild habitats as under-story woodland plants) Blueberries grown in the UK should always be sited where they will receive at least 3 to 4 hours of direct sunlight per day, and preferably more.

Introduced in 1994, Vaccinium 'Chandler' has the largest fruit of any Blueberry variety.

As much as we love the fruit, and also admire the Spring flowers, the main reason that we have over 50 Blueberry plants growing across the garden is actually what they plants do after having fruited. Once Autumn starts to kick in then the foliage turns a dazzling array of yellows, oranges and reds, and Vacciniums are undoubtedly one of the most reliable of all autumn colouring shrubs, never failing to create a blazing display, regardless of  whatever the hugely variable British climate throws at them.

Just a taste of the autumn colour that adorns the plants.

Of the many named varieties of Blueberry – selected for fruit size, flavour or abundance – there are now a decent selection readily and widely available to British gardeners. Provided their simple soil tastes can be met, and they are kept reasonably moist during the growing season, the plants are completely trouble free to grow and bushes will continue to reward with bigger crops of fruit each year as they mature. Two or more different varieties should be planted together to ensure cross-pollination and a good fruit set, then it’s largely a question of sitting back and let time – and the bees – do their work. There can be few plants that combine ornamental and culinary qualities as well as Vaccinium corymbosum, and Blueberries can and should be integrated into many of our gardens with great ease.

Selected in Australia in the 1970's Vaccinium 'Brigetta' has become one of the most widely grown commercial varieties of Blueberry.


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Knifophias: their rise and fall…and rise and fall…

Thursday, July 28th, 2011

It’s always fascinating to chart the progress of plant fashions. Some plants that have been quietly growing away in a few gardens are suddenly swept up in a horticultural fervour to become everyone’s must-grow of the season. Others, once favoured, are cast aside and occasionally banished altogether from all “fashionable” gardens, sometimes to be entirely lost to generations of future gardeners, or else kept alive only by a faithful few, waiting for their moment to return to centre stage.

Kniphofia uvaria - where it all began, with the familiar Red Hot Poker.

Kniphofias, commonly known as Torch Lilies, are a prime example, and these exotic, African, summer-flowering Lily relatives have had more than their fare share of rises and falls in the fashion stakes. Kniphofia uvaria – the classic Red Hot Poker – is a native of South Africa that was originally introduced into European horticulture in Victorian times. The huge stems, reaching to nearly 2 metres in height to bear the vividly coloured flowers, were quite the sensation back in the late 1800′s, and the plants were highly sought after, fitting easily into the Victorian gardening passion for all things exotic.  However coming, as they do, from relatively arid regions, these Pokers could not be grown alongside other prized hot-house exotica, and the plants were, in any event, quite hardy enough to live in outdoors, so they were duly planted out in front gardens and amongst borders.

Kniphofia 'Shining Sceptre' - one of the new generation of hybrids.

Once integrated into general garden planting schemes their inherent showiness started to divide contemporary garden writers, many of whom found them vulgar, coarse and brash. All too soon the Poker’s star was on the wane, and throughout the first half of the 20th century they were not thought fit for planting at all as the passion for recreating the traditional English cottage garden came to the fore. But this was just their first ride on the roller-coaster of fashion. By the 1960′s pop culture was beginning to have a dramatic effect on gardening tastes, and the big, brash Red Hot Poker was just the thing to inject the fun back into the fusty, fussy gardens of England. Their popularity exploded as never before and by the 1970′s Knifophia uvaria was literally everywhere – widely planted both in individual gardens and municipal schemes.

Kniphofia 'Brimstone' - flowers of pure canary yellow.

All things change, however, and within another decade their ubiquity saw the plants castigated as never before – this time not only were they deemed vulgar but also now common – the very epitome of bad taste. So plants were dug up and composted across the land as new fashions for cool colours and subtle foliage effects started to take a hold. This time ’round, however, their time in the shadows was to be relatively short lived  as two different factors came to bear.

Kniphofia 'Samuel's Sensation' - tall flowers of solid orange-red.

Firstly, there was a discovery of the remainder of the genus. K. uvaria is only one of over 70 species of Torch Lily, and until the tail end of the 20th Century very few others were grown or indeed available to gardeners to consider growing. However as garden writers such as Beth Chatto started planting, hybridizing, and extolling the virtues of the smaller, more elegant Kniphofias word slowly began to spread.

Kniphofia 'Little Maid' - one of Beth Chatto's introductions, with slender, cream coloured flowers to around 60cm.

These “new” plants (many of them wild species that had simply never previously been utilised in the garden) were often versatile and subtle and were readily integrated into a wide array of planting styles and schemes, even, ironically, the cottage garden whose bumptious informality had once been the nail in the coffin of the original Red Hot Poker.

Kniphofia 'Jenny Bloom' - one of the current must-have varieties, with flowers of coral-apricot and slender, grass-like foliage.

The second factor was also instigated by garden writers, and Christopher Lloyd in particular. He deliberately, and quite controversially at first, flew in the face of what was perceived to be good taste, and sought to introduce drama, vivid colour, and above all fun back into the garden. His now world-famous “hot colour” plantings were a reaction against the ever more restrained and subtle naturalistic plantings that were dominated by the subtle texture of grasses. Big and bold was his maxim, and as others came to realise that rules could be broken and gardens could be both relaxed and exciting, copy-cat hot plantings started springing up all over the country, pushing the good old Red Hot Poker back to some kind of prominence once again.

Kniphofia caulescens - much sought after for it's highly architectural, Agave-like, steel-blue foliage.

Other species, and Kniphofia caulescens in particular, have become part of the vanguard for architectural plants and are highly sought after for use in modern, formal, often urban settings as well as for more relaxed tropical plantings where they rub leafy shoulders with the likes of Cannas, Gingers and Tree Ferns.

Kniphofia uvalis 'Nobilis' nestled in the Hot Border at Christopher Lloyd's Great Dixter garden.

Although it’s now widely available in a diversity of forms, this time around K. uvaria isn’t the focus of the main attention. An explosion of new forms and colours have reached nurseries and are now available to satisfy the demands of both the hot colour camp and the cool and elegant camp – strength through diversity, you could call it. Kniphofias now supply flowers in bright red (of course) orange, salmon, apricot and canary yellow as well as cream, chartreuse and white, whilst they range in stature from the 2 metre giants to the positively petite, at 50cm or so.

Kniphofia 'Percy's Pride' - one of the most truly green-flowered varieties.

The foliage too, can be bold and hugely architectural or slender and neat – almost grass-like in fact. Their inherent verticality is often used by garden designers to provide a counterpoint to lower plants, and they sit easily and comfortably in many borders. It helps, too, that the plants are extremely hardy and well-used to summer rain, although their native South African habitats also provide them with a dry winter dormancy, which means that good, sharp drainage is essential for long-term success in British gardens.

The delicate beauty of Kniphofia 'Vanilla' is a world away from the old image of the Red Hot Poker.

The best forms of Kniphofia are now rightly and widely championed with major flower shows readily extolling their virtues as they regularly sit amongst the most highly prized of all garden plants – the smaller, cooler coloured varieties, in particular are deemed to be seriously fashionable additions to any 2011 garden.

Kniphofia 'Ice Queen' - pale green flowers that open to near white.

So now, after such a roller-coaster ride on the whims of gardening fashion, the new and ever expanding diversity of forms, colours and uses of Kniphofia, coupled with their relative ease of growth in the garden, may just have finally secured these fascinating plants a permanent place in horticultural hearts.

Kniphofia 'Toffee Nosed' - with highly unusual copper-tipped cream flowers.


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Vermiculture.

Thursday, July 21st, 2011

Two blogs ago I looked at the variety and number of worms present in our gardens and the crucial role that they play in maintaining and creating soils. You can get really pro-active, though, and harness the power of worms even more directly by turning your hand to vermiculture (the keeping of worms) by creating your very own earthworm hotel in the form of a wormery. Wormeries are an efficient, easily maintained and eco-friendly way of disposing of much of your garden and kitchen waste. Once the worms have done their thing they will not only have composted and disposed of your waste but will also provide you with two wonderfully useful end products: supremely rich, crumbly, ultra-high-grade compost – known as vermicompost – and concentrated liquid plant feed.

Vermicompost - almost good enough to eat!

Earthworms are the most efficient and successful detrivores to have ever evolved. Each individual eats, digests, excretes, and thus processes, anything up to it’s own bodyweight in decaying plant material each day. Together, a healthy and active population of earthworms can process pretty much all the suitable material that you can find, greatly reducing the overall volume of  your waste. The solid material that they produce – the vermicompost – can be used directly in the garden or in pots as a topdressing, planting material, or a soil conditioner/improver, whilst the liquid needs to be diluted at the rate of around 10 parts of water to one of concentrate.

It is estimated that each individual in the UK generates something in the order of 500kg of waste on an annual basis, and that each household collectively throws away over a tonne of waste every year. Something like 70% of this household waste has the potential to be either recycled or composted. Despite the fact that the majority of the people now regard recycling as worthwhile, currently only 14.5% of dustbin contents actually are recycled or composted. As a result many local authorities now offer for sale to the public compost generated by their own recycling efforts.

However, it makes far more sense for the individuals who are generating the waste to take direct responsibility for the disposal of at least some of the compostable elements. This, surely, is the most viable model for the future of kitchen and garden waste, saving money and time for the local authorities currently charged with it’s disposal (and by extension for the council tax payers who fund the process) and simultaneously providing a valuable source of planting raw materials for households that would otherwise have to buy them in. That’s what I call a win/win.

Of course many households who have access to an outside garden already do compost at least a proportion of their waste via their compost bins and heaps. Nevertheless, wormeries provide an invaluable alternative strategy for all households – they can process compostable waste far more rapidly than the average compost heap whilst opening up composting to those who have very limited outside space, or even no outside garden at all.

A 100 Litre wormery.

The equipment to create a wormery can readily be purchased, and generally consists of a large plastic bin with a tight-fitting hinged lid containing airholes and an internal perforated platform that separates the liquid waste from the solid. The bin is also fitted with a tap at the base from where the liquid can be drawn.

The earthworms that live and work within the wormeries are not the regular, soil-dwelling species that populate much of our regular garden soil. Terrestrial species would not survive in a wormery, instead one or more of the different species of British native compost worms must be used: composting worm (Eisenia andrei), red tiger worms (Eisenia foetida) or brandlings (Dendrabeana venera). The inhabitants for your wormery are generally supplied along with their living quarters, but failing that they can also be sourced from fishing shops or some organic gardening suppliers.

Compost worms - Eisenia foetida AKA Tiger Worms.

A well-maintained wormery should be odour-free, and so can happily live right outside the kitchen door or even indoors, where practically possible. To start the wormery place a single sheet of newspaper (about 20cm square) onto the separating platform and cover this with dampened, shredded newspaper. To this add a small amount of peat-substitute compost, such as coir, leaf mould or any other well-rotted sterile compost. The worms can now now placed into the middle of the bedding in their new home, along with their first meal – which should be no more than three or four handfuls of kitchen or garden waste. The lid should be left open for ten minutes or so, so that the light will encourage the worms to burrow down into the bedding. No additional food should be added for the next 7 days.

Wormeries may readily be located just outside a house door.

Once the worms have bedded in, they will start to increase their activity and speed of feeding. Initially add only small amounts (perhaps three of four handfuls) of waste each week and monitor to ensure that it’s all being digested and is disappearing as it should. Once the initial settling-in period has passed then kitchen and garden waste may be added at the rate it becomes available, ideally every day. Tough and woody material should be chopped up as finely as possible and the whole contents should be gently mixed through every so often to ensure an even distribution of worms and material.

Most wormeries are housed out of doors, and worm activity will slow with falling winter temperatures, however, if the wormery is sufficiently full at the start of winter, then the heat generated by the process of decomposition is generally sufficient to prevent the internal temperature of the wormery from dropping too much. Insulating the wormery over-winter can be a great help, and of course it can also be moved into a shed or garage to help maintain temperatures, particularly during very cold spells. Equally wormeries should never be placed in strong sunlight as the compost worms will not survive temperatures above 40°C.

When the wormery is nearly full and the material fully composted the contents will have a dark, spongy, soil-like appearance. Remove the worms, which should usually be in a layer just below the surface, and place them temporarily in a bucket or other suitable container. The compost may then be emptied out of the bin where you intend to use them or saved for use as an ingredient for making up your own potting compost. Your worms can be replaced into the newly set-up wormery and used for making the next batch of compost. It is usually possible to harvest worm compost from your wormery about every four to nine months, depending on temperatures, location and material used.

Most kitchen and garden vegetable waste can be added to a wormery – anything that you would add to a compost heap, essentially. However, compost worms cannot tolerate acidic conditions, and the failure of a wormery is often down to the pH dropping too low. This is further verified by the appearance of tiny cotton thread-like white worms in the compost. The addition of calcified seaweed, or crushed eggshells, well mixed in with some dampened, shredded newspaper, should restore the balance.


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Remarkable Rowans.

Thursday, July 14th, 2011

2011 is shaping up to be a bumper year for fruit and berries. All of the hot sun and near-drought conditions of Spring allowed the mass-pollination of flowers by feeding insects – unhindered, this year, by rain or heavy cloud – whilst the recent summer rains have promoted the swelling of the subsequent fruit to terrific proportions. Our hedgerows are filled with the glowing gold and scarlet of Viburnum berries along with the over-sized, ebony-black hips of wild roses, and will soon be heavily laden with what looks to be a bumper crop of blackberries too. Elsewhere Malus (Apples and Crab-Apples) are all developing nicely, but they have been well and truly eclipsed by their close relatives the Sorbus, or Rowans, whose giant clusters of bright orange-red fruit seem to be festooning their owners branches with unusual abundance this year.

Sorbus aucuparia - our native Rowan. A tree in full fruit can easily rival many exotic ornamentals.

Our native species of Rowan, also known as the Mountain Ash, is Sorbus aucuparia. This is one of nearly 100 species of Rowan within the Sorbus genus, Sorbus being an unusual genus in that it is sub-divided into two very distinct sections: the Rowans (Aucuparia section) and the Whitebeams (Aria section). As the common name “Moutain Ash” implies, the species is a specialist of uplands, and very often forms the final tree line at higher elevations, with twisted, wind-blasted specimens often found clinging on in the most improbable and inhospitable sites. Although entirely unrelated to the Ash (Fraxinus species) Rowans do share the pinnate arrangement of their foliage with that genus, and all Rowan species have leaves that are divided into feather-like or fern-like fingers – the pinnae.

A single Rowan leaf, divided into feather-like pinnae or leaflets, which are themselves toothed at the margins.

Rowans have adapted not just to exposure and high elevation, but also to extremely acid soil conditions, where few other woody plants would survive. Such conditions are typical of our moorlands, of course, but, aside from out-and-out alkaline chalk-lands, Rowans are perfectly adaptable and thrive in virtually all soils. This adaptability, along with their general toughness and lack of major pests and diseases has seen Rowans widely used as street trees and in parkland plantings, but in many ways they are also amongst the very finest possible trees for planting in gardens. In common with most Rowans, Sorbus aucuparia is a small tree, with a delicate airy habit. That divided foliage ensures that no Rowan casts heavy shade, which in turn makes them ideal for under-planting with smaller shrubs and herbaceous plants. The leaves of the Rowan are also inherently attractive throughout the growing season, but take on a particular appeal in autumn when they start to tint to shades of red-purple and bronze.

Sorbus cashmiriana has somewhat larger individual flowers than do most other Rowan species.

Back in Springtime the trees produce large, and very densely packed corymbs of tiny, cream-coloured flowers. The flowering display is not generally considered of great ornamental interest, although I think they do have a bumptious, fluffy appeal, but, in common with many other creamy spring flowers, they are hugely attractive to bees, hoverflies and other pollen and nectar feeding insects. Finally, then, the result of all that feverish insect attention are the magnificent berries, produced well in advance of many other trees and in full scarlet effect by August.

Sorbus aucuparia flowers.

Rowans would be well-loved and widely planted solely for the ornamental effects of those berries alone, notwithstanding all the many other attributes that the trees have to offer, but the fruits are equally esteemed by many species of birds who often flock to the trees throughout autumn. Thrushes, Redwings are Waxwings are all devotees, and many other species will also make a detour to a garden bearing a fruiting Rowan tree. We humans too have long harvested the fruit to produce Rowan jelly – a marvellous preserve with a sharp, marmalade-like flavour.

Sorbus aucuparia berries.

As already mentioned, our native Sorbus aucuparia is just one of a large number of species of Rowan, and many new species have recently been discovered, named and introduced into cultivation following recent plant-hunting expeditions to the mountainous regions of South-Western China. Our native tree is well up there amongst the best of the genus, ornamentally speaking, but almost all of the species and their ever-expanding collection of hybrids are highly attractive, incredibly easy to accommodate and exceedingly well-worth seeking out and growing.

In a good season some Sorbus can produce jaw-dropping leaf colour - this is Sorbus sargentiana in full autumn finery.

There are a few much larger growing species, most notably the magnificent Chinese Sorbus sargentiana, with it’s huge sticky over-wintering leaf-buds, and 30cm long leaves that turn to vivid scarlet in autumn. Mostly, though, the Rowans are small to medium sized at maturity, often with a rather slender, upright habit.

Sorbus sargentiana is well-known for it's over-sized, sticky winter buds.

I’m a huge fan of autumn foliage colour. Over half of our entire garden is given over to autumn colouring trees, and Sorbus certainly contains some of the worlds finest. S. commixta, is one such, with leaves that consistently turn to burnt orange and glowing red in autumn. That species is another Chinese native, as is S. hupehensis, whose leaves have a distinct blue-ish cast, before turning deep red at the seasons end, as do those of the larger-leafed S. esserteauana.

Sorbus commixta - in full autumn colour.

As with all trees, autumn foliage colour can be inconsistent and short lived, dependent, as it it, on the vagaries of our climate, and most Rowans are undoubtedly grown primarily for their display of fruit. S commixta, S. esserteauana and S. sargentiana all produce berries similar to our native Moutain Ash, but the fruit colours within the Rowans extend well beyond fire engine red. Many of the Chinese species, including S. hupehensis, as well as S. forrestii and S. koehneana, bear white berries. S. cashmiriana has the finest berries amongst the white-fruiting species, with very large, marble-like fruit held in drooping clusters that remain on the branches long after the autumn foliage has fallen.

Sorbus cashmiriana - the berries are so large that they often weigh down the branches of the tree.

The newly introduced and highly desirable Sorbus rosea has gorgeous, large, clear-pink berries whilst those of S. vilmorinii start out rose red, slowly changing to pink and finally maturing to white flushed with apple-blossom, all against a back-drop of ever-intensifying red-purple autumn foliage.

Sorbus vilmorinii.

It’s hybrid S. ‘Eastern Promise’ is similar but with larger berries that retain their deep-pink colouration throughout. Yellow-fruited Rowans are also available, including S. ‘Golden Wonder’ and the very famous, wild-collected S. ‘Joseph Rock’, which is a truly outstanding prospect when laden with it’s golden berries against a kaleidoscopic backdrop of red, orange and copper autumn foliage.

Sorbus 'Joseph Rock'.


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Wonder Worms.

Thursday, July 7th, 2011

Most gardeners are very well aware that worms are crucially important garden friends, and that their presence (or absence) in soil is a good indicator of how healthy that soil is. But earthworms do virtually all of their work undetected and invisible to us surface dwellers, so the exact mechanisms by which they operate are somewhat more mysterious.

Earthworms have been dubbed “ecosystem engineers”, and, like their human counterparts, they are able to alter the physical structure of their environments. Worms move through the soil by means of burrowing, with different species specialising in either horizontal or vertical runways some of which can extend deep into the soil. These burrows create a network of virtual pores through which beneficial oxygen and water can enter and carbon dioxide can exit the soil. At the same time worms digest their way through their surroundings, literally breaking larger particles into smaller, and their resulting faeces (worm casts) are responsible for much of the open, crumb structure of the the best soils, which in turn allows access to plant roots and myriad other subterranean organisms.

An earthworm cast.

Improvement in soil structure is only the start of the story, however. Earthworms are detrivores – meaning that they feed exclusively on dead material – and they play an equally vital role in the decomposition of that organic material. The earthworms resident in your compost are busily munching their way through, and thus decomposing your garden and kitchen waste, and soil-dwelling earthworms are engaged in exactly the same process. Together with a galaxy of fungi and bacteria this process of decomposition releases the nutrients tied-up in dead plants and animals and allows them to be accessed by living plants. The volume of material processed in this way is pretty staggering – just consider, for starters, all of the autumn leaves shed by deciduous trees and shrubs each season that are efficiently and rapidly recycled back into the soil, a job done largely by worms.

The industrious work of earthworms also acts to mix together the different strata of soil. Nutrition is incorporated deeper into the soil (without which it would be rapidly leached of it’s goodness by rain and the feeding of living plants) and the fertile top-soil region is slowly expanded. These actions lead Charles Darwin to refer to earthworms as “nature’s ploughs” due to their ability to mix and fertilise soil with organic matter, but worms are hugely more efficient, and entire ecosystems are dependent opon their actions.

An earthworm - this one is Lumbricus terrestris - in its burrow.

Earthworms, as mentioned above, aren’t the only operators in the area of decomposition. In fact they are the  first level – the macro-scale when it comes to matters of micro-organisms – and fungi and bacteria take over where they leave off, breaking particles into even smaller pieces and fully releasing the nutrients within. For the most part, however, these fungi and bacteria are unable to survive without the presence of worms, who are, effectively, responsible for providing their food, so whilst worms can operate independently of their decompostion partners the same can’t be said of the bacteria and fungi. What’s more the higher the concentration of worms in a given soil the larger the presence of beneficial bacteria and fungi will be.

It comes as a surprise to many gardeners to learn that there are actually many species of earthworm present in a typical garden, and even more so to hear that they all specialise in different terrains. From a gardeners point of view the species can be broken down into four broad groups.

First up are the so-called compost earthworms, so-named for their love of compost bins. They require a warm, continually moist environment with a regular supply of new material on which to feed and are highly active, digesting rapidly and reproducing quickly too. The most commonly encountered species of the compost group are Eisenia fetida and E. veneta, both characterised by their relatively small size and bright red colour with distinctive paler stripes, which lends them the common name of Tiger Worms.

Eisenia fetida - one of the familiar Tiger Worm compost species.

The second group are known as the Epigeic earthworms. They live on the soil surface amongst the leaf litter – Epigeic literally means to crawl across the surface of the soil – and can be regarded as the first line of attack in the decomposition of material and the recycling of nutrients. These species do not burrow at all, but feed exclusively above ground, breaking-down organic material into pieces small enough for the subterranean species to access easily. Epigeic earthworms are generally also bright red or red-ish-brown, but they lack the stripes of the compost species. Common Epigeic earthworm species include: Dendrobaena species, Eiseniella tetraedra, Helodrilus oculatus, Lumbricus species and Satchellius mammalis.

Next up come the Endogeic earthworms. As might be imagined, these species both live in and feed directly upon the soil. They create networks of horizontal burrows through which they move and digest/excrete as they go and are able to burrow deep into the soil. Although they do re-use their burrows to some extent they characteristically create new burrows as they go. Endogeic earthworms are large in size and generally pale in colour, with different species appearing  pink or grey as well as green-ish or blue-ish. Common endogeic species include: Allolobophora chlorotica, Apporectodea species, Murchieona muldali and Octolas species.

Allolobophora chlorotica - commonly known as the Green Earthworm.

The final group are the anecic earthworms. These species make permanent, vertical burrows in the soil and feed upon surface leaves that they capture on the surface and drag into their burrows. The anecic species are the ones responsible for the familiar surface piles of worm-casts so often seen in lawns and other grasslands where they create middens that surround the entrance to their burrows. Anecic species are the largest of our native earthworms and are dark red or brown in colour at the head end with paler tails. The two most common species are: Lumbricus terrestris and Apporrectodea longa.

Apporrectodea longa - the Black-Headed Worm.

The anatomy of an earthworm consists of a simple digestive tube housed within a thick cylindrical muscular sheath that forms the body. That body is segmented with furrows on the surface of the body marking the division between each segment. The first segment incorporates the mouth of the animal, and has a fleshy, muscular lobe on the top. This lobe can be pulled in to seal the mouth off, or pushed outwards to investigate its surroundings. Aside from the mouth, each of the segments has a series of eight retractable bristles which together allow the earthworm to propel itself along.

Earthworms are hermaphrodites, with each individual possessing both male and female reproductive organs. When two earthworms are ready to mate they adopt a head-to-tail position, cover themselves in a layer of mucus, and exchange sperm. Each then forms a tube of mucous that detaches and moves forward along the body, collecting both the individuals own eggs as well as the sperm received from its partner en route.

Mating earthworms.

Fertilization subsequently occurs within this mucous tube which detaches from the front of the body and is deposited in the soil where it dries to form an egg capsule or cocoon, from which one or more young earthworms will eventually hatch. Many species are able to breed several times a year.

Earthworm egg cocoons - these are from L. terrestris.


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Misunderstood Bamboos.

Thursday, June 30th, 2011

One of the frequently asked questions at Gardeners forums and Garden-expert panel question-times goes something along the lines of:

“How can I control/remove/eradicate a bamboo that’s taken over the entire garden/neighbourhood/northern hemisphere…”

Well, maybe I exaggerate, but only slightly. Certainly bamboos seem always to provoke strong reactions in gardeners – loved and loathed in equal measure – but, as is so often the case with gardening, it’s all about having the right plant in the right place and too often these often magnificent plants are unfairly castigated due simply to poor planting choices. After all, most gardeners wouldn’t think of planting an Oak tree in a small back garden, and then be surprised when it turns into a forest giant, and some bamboos are in much the same position: victims of poor research and lack of forethought on the part of their original planters and forever destined to be progressively dug out and continually cursed.

Fargesia rufa.

But, as I often seem to find myself writing in these blogs, it doesn’t have to be that way. A lot of the bad press that bamboos have suffered is due to a basic misunderstanding of the nature of the plants. Many gardeners seem to thing of them as shrubs, and, like a shrub, they expect that once they get too large they simply prune back their top growth and keep the to a given space. But bamboos are, of course, grasses, rather than shrubs, and, like all grasses they consist of an underground rhizome and an above-ground network of shoots and stems – the “canes”, technically known as culms. Another key thing to remember is that there are an astonishing number of bamboo species – at least 5000, at the latest count – and these vary from tiny, slender grass-like pygmies to vast, towering, tree-like giants from which entire houses are built. So when a gardener asks about how to solve problems with “bamboo” it’s pretty important to know which bamboo they’re referring to.

Thamnocalamus crassinodus.

From a horticultural perspective you can very broadly divide the species into two simple groups – the clumpers and the runners. Clumpers are defined by having a very tight, non-spreading rhizome system from which the culms arch outwards, like a fountain. These species are, by definition, entirely non invasive, but this also makes them rather difficult (or at least slow) to propagate, since the very congested rhizomes are hard to work with and difficult to divide. The runners, by contrast, have entirely erect culms that emerge in a line from their spreading rhizomes. When growing vigorously, and without major competition these rhizomes will spread out in all directions from their central start-point, and produce curtains (bamboo curtains?) of culms along their routes.

Himalayacalamus falconeri.

So here’s where gardeners have to bite the bullet. Realistically, no running species of bamboo is remotely suitable for planting in a regular sized garden without being containerised beneath the ground to reduce the spread of the rhizomes. Yet it is exactly these running species that are most frequently offered for sale, in part because of the great beauty of some of them, but mainly because of their ease and speed of propagation – in other words nurseries can make more plants, and so more money, more quickly from these species.

In a parkland or large country garden where they can reach their full potential these running species are truly magnificent. Best known amongst them are the Phyllostachys species – large (often very large) bamboos some of which have gloriously coloured culms of yellow, green, purple and black. Phyllostachys nigra – the black-caned bamboo – is viewed as a near-essential element in many fashionable garden designs, and is particularly popular in urban settings. It’s the least vigorous, and also one of the smallest of the Phyllostachys, but will still form an extremely substantial plant of tree-like proportions in just a few years when planted in open ground, as well as running in all directions when left unchecked.

Fargesia fungosa.

I am partial to Phyllostachys myself, and have a collection of them in the garden, but here they have 5-or-so acres in which to make a home, and even then they need much annual work to keep them in place. So instead of attempting to tame these wild beasts of the garden, I would always recommend selecting and planting only the clump-forming species of bamboo. Many of these are native to higher elevations in China and the Himalayas, and the best of them can easily rival or indeed surpass the appeal of the best of the Phyllostachys species.

Fargesia nitida Jiuzhaigou No. 1.

One of these clumpers is, in fact, very widely available and gardeners should have little trouble finding a specimen even in non specialist garden centres: Fargesia nitida was one of the first bamboos to be introduced into Western cultivation, with seed arriving in Europe towards the end of the 19th Century. It is a small to medium sized species, reaching around 4 metres, although often no more than half this height. The culms are slender and often arch over, affording the entire plant a airy, elegant appearance. Best of all, though, the culms vary from deep black-ish purple though to rich red, particularly when the plants are grown in full sun, making F. nidita an eminently suitable replacement for it’s  towering black-stemmed cousin Phyllostachys nigra.

Fargesia utilis.

Fargesia is home to an array of other very beautiful bamboos, many of which have only recently been introduced into cultivation. F. perlonga, F. rufa, F. fungosa and F. yulongshanensis are all very fine, smaller species, well worth seeking out for their intricate charms. On an entirely different scale is Fargesia utlis. This ultimately becomes a very large plant, but is still confined to a tightly clumped centre from which the culms arch outwards like an exotic green fountain. The species is too big for use in the border, but makes for a magnificent lawn specimen.

Drepanostachyum hookerianus.

Drepanostachyum and Himalayacalamus are two closely related Himalayan genera, all of whose species are very beautiful, if somewhat less hardy than the Fargesias. D. falcatum has narrow culms that age to bands of crimson, yellow and green, H. falconeri has culms heavily striped with cream, whilst those of D. hookerianus emerge with a waxy blue sheen and age to deep red in the sun.

Thamnocalamus crassinodus 'Gosainkund'.

My favourite genus of bamboo, and the one that I would never want to be without in this or any other garden, is undoubtedly Thamnocalamus. These are hardy, high-altitude, clump-forming bamboos, primarily native to the temperate forests of the Himalayas. T. spathiflorus has culms that age to burgundy, whilst in T. aristatus they become clear yellow.

Thamnocalamus crassinodes 'Kew Beauty'.

Finest of all, however, is the highly variable T. crassinodus, in which the culms typically emerge powder-blue, strongly contrasting with their protective, papery, fawn, sheaths.  Some forms of the species maintain their white-blue powder covering to maturity, whilst in others, such as ‘Kew Beauty’, the culms turn to a deep red when grown in good light. All have the most beautiful, narrow leaves, that help to create a particularly beautiful impression both up-close and at a distance.

Thamnocalaus crassinodus, once again.

There are many other worthy and hardy clump-forming bamboos too, but my overall plea would be to take the time to investigate the possibilities that these plants have to offer, and then seek out the best to suit your space as well as your tastes. It may take more time and potentially more money at the outset, but the long-term results will repay the initial outlay and effort many times over.


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Herb Spirals.

Thursday, June 23rd, 2011

Growing your own produce has become de rigueur for almost all gardeners, and while fruit and veg are the backbone of any kitchen garden herbs occupy a special place in our hearts. There’s no doubt about it – herbs are hip! They straddle the boundary between the utilitarian, productive garden and the ornamental garden, and of course help bring the kitchen into the garden and vice versa.

Herbs are also very easy to grow and fun to collect, experiment with and above all to savour. It can’t be any coincidence that the rise in the passion for cooking, and Mediterranean food in particular, has also brought a boom in the number and varieties of herbs that are readily available to the gardener. At the same time there’s been a resurgence of interest in some of our native plants and the nearly-lost kitchen uses to which they’ve traditionally been put .

Herbs can be tucked in amongst other kitchen plants and can readily be grown in containers of all shapes and sizes, but for those with a real passion for these aromatic and sensual plants, there’s nothing better than a dedicated herbal bed, and the big-daddy of all such beds is the herb spiral. Herb spirals pack an array of handy benefits into one simple idea.

Herb spiral made from a variety of materials showing the compass points.

Designed on permaculture principles, the spiral is intended to provide optimum growing conditions for the plants whilst at the same time saving on ground space. By figuring out the compass direction that each side of the spiral faces you can then readily provide a variety of different environmental conditions, and so grow together herbs that wouldn’t ordinarily thrive when simply planted side by side in open ground. Most of the Mediterranean species, for example, require as much sunlight, heat and sharp drainage as you can give them, and can best be grown on the top (where the drainage is very significantly enhanced) and on the south-facing side of the spiral, facing into the sun. Others, such as mints, lemon balm, chives and wild garlic all relish the shade of the north facing side of the spiral and the damper, less harshly drained foothills at the base.

The resulting community of herbs can accommodate even quite large plants and yet the whole structure can also be grown on a terrace or even a roof garden. The extra elevation that the plants gain helps greatly with drainage in general, but also allows the soil to heat up far more quickly and effectively than a comparable area of flat ground, as well as attracting bees and hoverflies. Once the herbs have established and filled the growing spaces nicely then the maintenance of the spiral is virtually nil, save for the odd bit of pest control when molluscs decide to explore the ramparts.

This new spiral is made from lengths of recycled fencing.

To create a spiral you first need to find a suitable site. It should ideally be around 2 metres in diameter, (although can, of course, be either larger or smaller to suit your needs) and should preferably be within a short dash of the kitchen for maximum usefulness, although the key requirement is to find a site which has the highest exposure to sun, to suit the thymes, sage & rosemary; if that means a longer trip from kitchen to spiral, then so be it.

Mark out the footprint of the spiral by placing a bamboo cane or similar in the centre of your chosen site, attaching a 1 metre long piece of string to it,  and scoring the ground or soil in a circular arc around the centrepoint. Next place a thick layer of old newspaper, cardboard or mulch around the outer part of the circle to prevent intrusion by weeds and then you’re ready to start construction. The structure of the spiral is most usually made from rocks, but wood, bricks or even old wine bottles can also be used. The open end of the spiral must face north, so make sure you know your bearings before you begin to build up!

A brick spiral, mid-construction.

Start by laying out the basic shape of the spiral on the ground as a foundation and firmly infill behind with compost and/or soil to help to strenthen and hold the structure as you go. Once the outer circle is complete then, starting at the northern edge once again, you simply build the spiral upwards and inwards, using the largest, heaviest stones at the base. The optimum height at the centre is around 1 metre, and as you build upwards, start to add coarse gravel into the soil/compost mixture to optimise the drainage. Leave some depth room for extra topsoil and planting compost, as well as for the plants themselves of course, this will also ensure that the compost doesn’t overflow and get washed overboard by heavy rain.

A flat stone spiral, ready for planting up.

Once it’s fully built then water the whole structure thoroughly and allow it to settle. there will be lots of air pockets and the soil level may drop considerably in some cases, so be sure to top up before planting. Aside from full-blown trees such as Bay then pretty much any and all herbs that take your fancy can be fitted into the spiral, just remember to research their respective growing requirements and site them accordingly, from hot and dry at the top and south sides, to damp and cool on the north and base of the spiral.

A lovely stone-built spiral with it's herbs maturing nicely.

A well built spiral made of appealing materials makes for a very attractive addition to any garden, and the boost in growth rates for the plants will ensure a goodly crop of herbs for the kitchen too.


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Planting for Wildlife: The Wild Roses.

Thursday, June 16th, 2011

There can be few gardens across the land that don’t contain at least 1 or more roses. Whether they were planted by their current gardener or inherited along with the house and the rest of the original planting, our love affair with the rose has seen them proliferate across our gardens like few other varieties of plant. In many ways, though, they have become a victim of their own success – too ubiquitous and therefore too common to be in any way fashionable. The “modern rose” is also often a very man-made affair – all pumped-up in a powder-puff multitude of petals and a bewildering array of colour combinations – not the kind of thing that sits well with the trends for naturalistic planting and wild-looking plants.

Rosa rugosa, together with a feeding bumblebee.

The hybrid T also comes with some serious baggage – associations with disease (Blackspot in particular), aphids, annual pruning regimens and gaunt, bare, ugly looking bushes through winter. It’s fair to say that many Modern Roses cannot, in fact, be successfully cultivated without resorting to an armoury of defensive sprays and potions to fend off the worst of their many enemies. You could even say that they represent the worst excesses of old-style gardening as a kind of attack on nature, something to be tamed rather than celebrated in it’s wildness. But to tar all roses with that same brush would be a serious mistake.

Rosa canina - the small hips are both attractive and loaded with vitamins.

Rosa is a pretty large genus with over 100 species. Most of these are native to Asia, but, quite remarkably perhaps, some 20 different rose species grow wild in Britain. The majority of that number are made up of non-natives that have escaped from early attempts at cultivation and have naturalised themselves, and still others are varieties that differ only slightly from their species. We do, however, have 4 identifiably seperate native species of rose, all of which are quite charming and none of which suffer from any of the drawbacks associated with their over-blown modern hybrid relatives.

Rosa canina in flower.

Rosa canina (the Dog Rose) is probably everyone’s archetypal idea of a wild-rose. The best known of our native species, it’s a familiar sight in many hedgerows and banks where the slender stems scramble through the stronger supports of other shrubs. Like all of the wild roses the fragrant flowers are simple and single, and open flat to reveal a central boss of golden stamens surrounded by petals that vary in colour from pure white through to deep pink, but are most commonly seen in pale, apple-blossom pink. These flowers are followed by striking flask-shaped, bright vermillion-red fruits.

Rosa arvensis - smothered with summer flowers.

Rosa arvensis (the Field Rose) is a more vigorous climbing species that readily forms dense mounds of stems and foliage and is ideal for growing through a tree. In the wild the species is most usually found at woodland margins, as well as in older hedges, but it’s long been cultivated too and forms one of the essential elements of the traditional English Cottage Garden, which is never complete without it’s climbing rose around the front door. The flowers are invariably white and somewhat smaller than the Dog Rose. The fragrance is also less notable than in that species, but what they lack in individual prowess they make up for in abundance, with the plants becoming smothered in flowers throughout summer and equally numerous small, rounded, sealing-wax red fruit in autumn.

A Blue Tit samples the hips of Rosa arvenis deep in a snowbound winter.

Rosa rubiginosa (Sweet Briar) is a free-standing shrub, rather than a climber, and has thick stems clothed with a formidable armoury of thorns – hence the common name. The foliage is deliciously scented of apples and the beautifully formed flowers are clear-pink fading to a white centre and are also wonderfully, and famously fragrant. Once again, the flowering display is followed by an even brighter one as the teardrop-shaped red hips swell through the autumn. Sweet Briar makes an excellent and very dense hedge in it’s own right, and is readily grown, even in quite poor soils.

The distinctive fruit of Rosa rubiginosa.

The last of our native species, Rosa pimpinellifolia (Scotch Rose), is perhaps the least well-known, at least in it’s true, wild form, but is certainly my favourite of the four. It forms a small bush, commonly found growing wild amongst coastal sand dunes, and limestone pavements, but completely adaptable to virtually all garden conditions. The entire plant is more delicate than the preceding species; the foliage is very heavily divided giving an almost fern-like quality to the plant. The stems are extraordinarily bristly and the young foliage is bright red fading to deeper red with maturity, whilst the white flowers are small, but are borne in profusion throughout May and June when they perfume the air. The globular hips appear from mid-summer are deep purple eventually maturing to shining ebony-black.

Rosa pimpinellifolia.

Added to these four species I have to also single out one of the escapees, now very well established in the British countryside, namely Rosa rugosa, (Ramanas Rose). This is a medium-sized, free standing shrub, strong-growing and rather coarse in appearance, but invaluable in the garden in so many ways. The large flowers are typically dark pink, but the best form, ‘Alba’, has flowers of pure white with a contrasting golden centre. These are very powerfully and intoxicatingly fragrant, filling the air with a spicy warmth – truly outstanding. The plants flower continually for many months running from mid-spring right through to late autumn. As a result they never create a huge floral display but the enormously long flowering season is ready compensation. The hips mature to bright tomato-red and, indeed, are also shaped exactly like cherry tomatoes – highly decorative. Rosa rugosa makes a fantastic hedging plant either in it’s own right or mixed in with other native species.

The large, plump hips of Rosa rugosa alba.

All of these 5 roses are beloved by wildlife and make a near-essential edition to any wild or wildlife friendly garden. Those beautiful and fragrant flowers are visited by a large array of insects, butterflies, bees, moths, hoverflies, beetles and wasps. Bumble-bees in particular seem continually drawn to wild-rose flowers and readily gorge themselves on the plentiful pollen and nectar within. Rose hips are equally important sources of food, particularly since they are extremely long-lasting and often persist well into winter when many species of fruit eating birds, along with deer, rabbits, mice, squirrels and other winter foragers rely upon them for sustenance. Finally the bushy, vigorous, multi-branched and thorny nature of roses makes them perfect for nesting birds and small mammals who can readily create a secure and well-defended home in amongst the branches.

Rosa pimpinellifolia fruit, slowly ripening from deep red to black.


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