News Tagged ‘Pest Control’

Planning for a greenhouse.

Monday, April 12th, 2010

Practical and functional, no garden should be without a greenhouse.

Installing a greenhouse is one of those pivotal moments for any gardener. Having a covered area in the garden, be it a conservatory, porch or even a cloche or cold frame, greatly enhances the scope of what you can grow and when, but once you have a greenhouse you’ll wonder how you ever managed without it.

Greenhouses create longer growing seasons, provide protection, warmth and additional humidity for their leafy occupants. They allow you to grow entire ranges of plants, both edible and ornamental, that wouldn’t otherwise be possible.

Seeds can be sown much earlier and bulbs and containers started safely into growth in late winter or early spring. Perhaps most important of all, greenhouses also provide a sheltered, dry and wind-proofed working environment which will work wonders to encourage you out into the garden on otherwise grey, cold and uninviting days.

Site.

A wooden potting table - essential greenhouse kit.

Generally speaking you might have only limited possible sites available in your garden, or quite possibly no choice whatsoever as to where to situate a greenhouse. There is a temptation to locate them as you would a shed – i.e. tucked away out of site in an unused and probably uncultivatable corner of the garden.
Unless you’re planning to house a specialist fern collection in your greenhouse, this kind of location is really not going to work. Another common mistake is to situate with the longest side facing due south into the sun. This will create unfeasibly high summer temperatures and you may end up oven-baking all your plants as a result; at best you will be continually struggling to keep ventilation and humidity high enough and may end up having to shade the entire greenhouse in an effort to keep things stable.

Where possible the very best site will have the longest sides of the greenhouse facing east and west, the door/ventilation end facing south and the northern end against the protection of a wall, hedge of fence.

Choice of greenhouse.

A typical flat-pack aluminium greenhouse.

The best value greenhouses are those that come flat packed for self-assembly. If you have the patience and (ideally) a couple of willing helpers on hand then these aluminium and glass constructions are extremely good value and can provide an ideal solution.

Go for the very largest size that you can afford and can accommodate. You may not think that you’ll fill up all that space, but believe me, no matter how large your greenhouse you will soon find yourself wishing you could squeeze in a little more.

Also the larger the enclosed space the more stable the humidity, temperature and environment within, and the less susceptible it will be to heat loss overnight and over-heating during the day.

Finally, ventilation is an absolutely part of any greenhouse so make sure that yours has as much as is available, preferably allowing for a cross flow of air from end to end and/or side to side of the structure.

Access to services.

In order to make the most of your greenhouse you will need access to electricity and a water supply. Once you have a collection of plants under glass you will want to ensure they don’t get hammered by extremes of cold, and, depending on what you are growing, you may also need to guarantee a frost free environment year round.

A water butt set up to collect run-off from the greenhouse roof.

There are a variety of gas heaters available, but they can be tricky to run and expensive to buy. The best of them also need to be installed by a qualified engineer, and might end up costing more than the greenhouse itself. Having power available in your greenhouse will allow for cheap and easy low level heating if and when it’s needed and of course will also allow you to add a light for those dark winter days.

Access to water is even more important, since you’re going to be using this, quite possibly on a daily basis, for a large portion of the year. Consider installing a tap or at least running a dedicated hose to the greenhouse, and most definitely install a water butt to capture the rain that falls on the large glass surface of your greenhouse. Using captured rainwater not only makes good environmental and economic sense but is also far better for all plants, and absolutely essential for the likes of Orchids & carnivorous plants as well as many seedlings.

Think also about your own access to and from the greenhouse and consider adding some additional paving or gravel in order to keep the entrance clean and prevent mud being traipsed in from a soggy wet garden.

Cleanliness.

All of the warm, humid & sheltered conditions that allow for great plant growth will also create an outstanding breeding ground for fungi, bacteria and plant viruses, not to mention weeds and a whole gaggle of flying insect pests. Keep work surfaces, glass and flooring clean, tidy and hygienic and you will greatly reduce the opportunities for any of these nasties to gain a foothold.

Greenhouses are not garden sheds and should not be used as dumping grounds for all the things that you want to tidy away – the transparent sides should put the kibosh on that idea anyhow, since everything inside is effectively still on display.

Equipping a greenhouse.

There are a few useful bits of kit that you should have lined up ready for your new glassy space. Top of the list is a solid, steady work surface set at a height comfortable for you to work with and strong enough to hold pots, compost and whatever else you’re likely to need. Consider using a table and perching seat – they don’t take up much room and make can make working conditions far more comfortable.

Working tray.

A large, shallow sided tray is also pretty essential. This will allow you to do a whole range of gardening tasks – mix composts, pot up plants, turn out old pots etc. – and all in contained, clean and hygienic conditions.

You’re also going to need an easily accessible and preferably containerised or divided tidy or storage area for tools, labels, pens, ties, plant foods and so on. Think about layout too, and where best to accommodate composts, pots, trays, canes and all the other items so that they are ready for use.

I like to have two separate bins running in the greenhouse. In fact it’s the very first thing that I set up and won’t start any work without them, as it’s amazing how much debris you produce whilst working in a greenhouse. Much of it can be composted, but some things, like old broken plastic pots and seeds trays or diseased plant material, need to be kept separate for waste disposal.

Shade netting - have some on hand long before it's likely to be needed.

Tools will vary according to your needs and the nature of what you will be growing, but secateurs, scissors, a hand watering can and a couple of sprays are all pretty indispensible in my experience.

Finally, unless you have indeed been forced to locate your greenhouse in a dark, shady corner where a shed might otherwise live, then you will almost certainly need some shading ready for extremes of temperature.

You can easily attach shading net to the inside or your glass walls, and some greenhouses come with their own shading systems too, but in either case you’ll need to have it ready to use well in advance of summer.


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T is for Trillium.

Friday, April 2nd, 2010

Amongst the most prized of all spring flowering plants are the Trilliums, a uniformly fascinating, beautiful and nearly unique genus of 43 species native to North America with a small handful hailing from Asia.

Trillium grandiflorum f. roseum

Whilst any display of spring flowering perennials is a pretty magical site, pushing, as they do, from near barren ground to display their flowering and leafy wears for all to see, there is definitely something really special about Trilliums.

They are the kind of plant that, when in flower, will cause even the most jaded non gardener to stop and stare, alongside the many converts and aficionados who will doubtless already be drooling with delight.

Trillium basics.

Trilliums grow from fleshy underground rhizomes (swollen stems) each of which produces just one single growth point. In mid spring – typically April in the UK – this slowly enlarges to form a single upright stem with a whorl of leaves on top of which opens a single flower. Over time these rhizomes reproduce themselves and form new growth points and eventually spread to create whole colonies.

Trillium chloropetalum.

There are, broadly speaking, two different groups of Trillium, each characterised by the flower, which either grows directly from the centre of the leaves, and is rigidly upright, or is held aloft on a short stem, and is often nodding.

The leaves of some species are almost as decorative as the flowers, being large, heart-shaped, and splashed, patterned  and blotched with silvery/grey/green, whilst flowers vary from snow white to pink and yellow with a large number of intense crimson, red-violet and blood red. These are plants that aren’t shy about making their presence felt in the garden, that’s for sure.

Cultivation.

Trillium cuneatum.

It’s fair to say that Trilliums come with something of a reputation for being hard to grow successfully. This reputation undoubtedly puts many gardeners off trying the plants, which is a shame, because, given half-decent conditions Trilliums are not problematic in any way and clumps will slowly enlarge and persist for many decades with really very little care, attention or intervention.

One thing that certainly is  true is that plants can be slow to establish, particularly if they are planted as dormant rhizomes. In fact they can sulk and fail to appear above ground at all for the first year – during which time they are actually making new roots and seeking to establish themselves into their new site.

Trillium flexipes.

All Trilliums are much better planted whilst in growth, preferable from freshly divided or already potted specimens, when they should get away quite happily and establish more readily.

In the wild Trilliums are plants of the forest floor, emerging before the leaves on the trees above them, and fading away by mid summer. Once established they can tolerate relatively dry conditions, but for the first year or so they benefit greatly from being kept moist.

Soil should be humus rich and well drained and the position should ideally provide dappled shade – just like any woodland floor in fact.

Trillium underwoodii.

The Asiatic species are much less frequently seen in cultivation and all prefer a richer, more moist soil. In the wild they often associate with bog margin plants like Skunk Cabbages (Lysichiton spp.) and given sufficient moisture at the roots these species they will also tolerate a sunnier spot than their American cousins.

Two species (T. undulatum and T. nivale) lovely though they both are, are much tougher to please and can’t really be considered suitable for garden cultivation outside the preserve of specialist collections.

Propagation.

Trillium erectum.

Most Trillium are pretty slow to bulk themselves up and it’s the patient gardener who gets to dig up and divide his or her clumps. Some species, though, do spread more rapidly and a few forms and hybrids, in particular, have proven to be keener to bulk up, but none could possibly ever be accused of being vigorous.

In the wild, of course, the species spread themselves pretty successfully by seed, and for a few lucky gardeners their plants do the same job without any assistance. Generally though Trillium seed is slow to germinate and the young plants painfully slow to mature to flowering size – four to seven years being the norm.

It’s this slowness to mature and reproduce that has given Trilliums their rather unjustified reputation for being tough to cultivate. Once you’ve seen a North American woodland floor carpeted, bluebell-like, with Trilliums, out-competing rival plants as far as the eye can see, you’ll have a tough job to believe that these guys could possibly be hard to grow!

Pests.

Trillium luteum.

Trilliums are pretty tough customers, absolutely bone hardy and, happily, are not attractive to many pests. Slugs and snails can be troublesome but are easily repelled from individual plants or small colonies, and it’s definitely worth protecting those beautiful leaves from being munched.

Rhizomes can rot when the plants are dormant if the soil is allowed to get saturated or is very poorly drained, and plants can retreat back under ground in severely dry conditions, but that’s about it in terms of common problems.

Trillium species.

Although some of the species are extremely expensive and rarely offered for sale there are a decent number of species and a few varieties that are fairly widely available and at reasonable prices.

Trillium grandiflorum double.

T. grandiflorum is the most widespread species, both in the wild and in cultivation, and makes for an excellent introduction to the genus. The flowers are large, sideways facing, pure white and very showy.

There are also a handful of extremely choice double-flowered cultivars as well as a beautiful pink form in cultivation. T. ovatum, is similar although smaller flowered, whilst T. cernuum and T. catesbaei have nodding flowers in white, often flushed with pink. T. flexipes is another widespread white flowered species, and one of the most willing to increase itself in cultivation.

T. rugalii is a particularly beautiful species. The nodding white flowers have heavily recurved petals that display a central contrasting ovary of deep maroon red.

Trillium albidum.

T. albidum is another gem, with upright flowers of white veined with rosy purple. It’s also gorgeously fragrant, reminding me of violets and roses. T. erectum is another widespread and easy species with recurving flowers of intense crimson red.

Probably the showiest of all Trilliums though are those with upright flowers of deep blackish maroon-red held over very large, marble-patterned leaves. There are a number of closely related species (T. cuneatum, T. sessile, T. chloropetalum & T. kurabayashii are the most widely cultivated, T. decumbans, T. underwodii & T. maculatum the most spectacular) that are variations on the same theme. They can be tough to distinguish from one another, and many in cultivation are wrongly labelled in any case, but they are all nothing short of awesome when in growth, so you won’t go far wrong with any of them.

Trillium flexipes hybrid.

There are several yellow flowered forms of different species, but the widespread T. luteum is always lemon-yellow and is the only yellow Trillium likely to be encountered in this country.

Several species naturally hybridise in the wild and others have been crossed in cultivation.

Although these hybrids aren’t often available, they are almost always extremely beautiful and highly unusual – as well as easily grown – so it’s definitely worth seeking them out whenever possible.


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Encouraging wildlife in the garden.

Friday, January 22nd, 2010

A fabulous little shield bug nymph that also happens to dine on aphids.

Down here in deepest rural Devon I’m lucky enough to garden on a piece of land that has never been cultivated or intensively worked before, let alone been bombarded with pesticides.

As a result the variety and sheer numbers of wild animals that live in the garden is a constant source of amazement to me, and the diversity of insect life in particular is especially remarkable, with new jewelled beetle, bee and dragonfly species seeming to appear each year.

But no matter where your garden is located, be it a city rooftop, a suburban terrace or a wild moor, the benefits of attracting and keeping wildlife in the garden are the same. If we grow plants and maintain gardens in order to have somewhere interesting and attractive to spend time, then when those same gardens are teeming with wildlife you’ve adding a whole other dimension of interest. It’s the difference between viewing a still life and 3D cinemascope.

Toad - natural slug killer par exellance.

But wildlife in the garden is not just ornamental. All gardens are, to one extent or another a war zone, with an array of slugs, caterpillars, weevils and other little pests just waiting till your back is turned before planning their next raid on your leafy lovelies.

By encouraging wildlife – be they birds, predatory insects or mammals – you are also recruiting foot soldiers to do your pest control work for you. Definitely what you’d call a win/win scenario.

Even more importantly though, from Honey Bees to House Sparrows to Small Tortoiseshells, our native wildlife continues to decline through habitat loss and by creating the right mini-environments and feeding points in your garden you can help to tip the balance back in their favour.

Southern Hawker - one of the first dragonflies to arrive at new urban ponds.

There’s no doubt that the single most important thing you can do for wildlife in any garden is to build a pond. Once established ponds become the centre of the garden as far as wildlife is concerned and you’ll see a big increase in the variety of animals visiting.

Toads and frogs will quickly set up base in even very small bodies of water and will repay you the favour by wolfing down large numbers of slugs and snails. Other natural slug killers that will likely visit a pond are hedgehogs together with an array of birds that will drink and bathe in shallow pond margins.

Along with being beautiful and fascinating to watch in action dragonflies and damselflies are also voracious predators of smaller insects. These miniature winged marvels disperse over huge distances and are adept at locating water bodies, with a few species specialising in colonising new ponds. The larger and deeper the pond the more species it will attract, but even the tiniest are wildlife magnets.

Throughout the rest of the garden animals will be looking for habitats to shelter and breed in, as well as food sources for themselves and their offspring. Trees can house huge communities of wildlife, and natives like Oak, Hazel, Willow and Hawthorn in particular are invaluable to birds, mammals and insects alike. Fruit trees – especially apple –  are also much loved by blackbirds and many others through autumn.

Flowering Ivy - a vital food source in late autumn.

Shrubs too are essential shelter habitats for wildlife, and a mixture of deciduous and evergreen plantings will encourage smaller birds including wrens and dunnocks, as well as providing winter accommodation for hedgehogs.

Flowering climbers and shrubs are also vital food sources for pollen and nectar-eating insects, especially butterflies, beetles and bees.

Flowering very late in the season, Ivy can be positively smothered with feeding insects like hoverflies come November and those same hoverflies will have spent their summers hoovering up aphids from the rest of your garden.

Of course all flowering plants, down to the smallest clovers, are also highly beneficial to feeding insects, and these will in turn attract larger predatory insects and birds.

Silver-Washed Fritillary feeding on bramble flowers.

A good diversity of flowering plants, with selections that flower throughout the year is the best wildlife recipe, whilst seed heads should, wherever possible, be left to provide essential winter food for birds and shelter for over-wintering insects.

Native species like foxgloves and primroses are particularly beneficial. If you can try to leave some nettles, thistles, brambles or vetch in a hidden and unused corner of the garden and watch the butterfly population boom.

Small log heaps will support a huge array of insect life, most of which, like slug-eating ground beetles, are highly beneficial whilst the warmth of compost heaps may, if you’re lucky attract slow-worms, wonderful legless lizards that will dispatch large numbers of slugs and snails. Nestboxes, not just for birds, but also for bees and ladybirds, are now readily available or easily built, and of course every garden should have at least one bird feeding station.

Blue tit - a feathered pest-control unit.

Providing peanuts and sunflower seeds through winter will literally mean the difference between life and death for the likes of Blue & Great tits, which are unable to forage effectively in frozen conditions.

Those same birds will then spend the following season searching your garden for caterpillars to feed their young.

One final thought, don’t be too tidy. Leaving things a little ragged, a little more natural will help to create a rich ecosystem of wildlife in your garden.


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