The very first garden that I was able to call my own was not located in the most promising site – a small, rather shady yard (courtyard would be way too grand a term) bounded by ageing wooden fences and with a solid concrete floor. Over a period of a few years I filled this little space with many dozens (possibly hundreds) of different plants that together created a little green oasis that carpeted the floor and covered the fences.

Massed containers create a dense green wall.

That garden was in East London, and, although I didn’t know it at the time, I was one of many gardeners worldwide who were exploring the limits of both their site and their plants by container gardening.

In theory you can grow literally any plant in a container.

Having seen Italian nurseries pot-growing full size, mature trees, many decades old and of many species, I can testify that the only limits are those imposed by the grower, rather than the plants – in other words, if you’re going to grow a 50 year old Magnolia in a giant barrel then you need to accept that it’s going to take some looking after.

Literally any space can be greened.

The benefits of container growing, on any scale, are considerable. For starters you can grow all manner of plants that would otherwise be unsuitable for your garden soil (assuming you have any). Want a Rhododendron collection but garden on chalk? No problem with containers. Want to grow Mediterranean herbs but have a cold, damp site? Again, it’s containers to the rescue.

Many urban gardens – like my old site – have no soil at all, and so containers can bring flowers and greenery to the most unlikely sites. Even those living in flats can use balconies, rooftops and window-boxes to green things up. The sky is quite literally the limit.

Silver, with black and blue, works well in a contemporary urban setting.

Even if you have a perfectly acceptable garden with lovely soil and a decent aspect, then containers still have much to offer. They allow you to bring plants up close to the house when they are at their flowering peak, and then rotate them away once they have passed. All manner of bright annuals can be used for temporary displays of colour, if that’s your thing, and you can endlessly rearrange your displays as if you were dressing a stage set.

Containers are also perfect for growing semi-hardy or even entirely tropical plants outdoors whilst the weather allows it, and those same plants can then be spirited away to the cosseting warmth of a greenhouse, or even indoors, when things start to cool off. Container growing is not just about ornament though, almost all herbs, vegetables, and some fruits can also been easily pot-grown, and in many cases actually provide for easier, less maintenance intensive cultivation too.  The key word is definitely versatility. Containers allow you to grown far more, for far longer, in far more places, than would even otherwise be possible.

A perfect carrot crop from a terracotta pot.

As far as the containers themselves go, again, the only limits are those of your imagination. Traditional pots come in three basic types – plastic, terracotta and fired/glazed clay. But of course there are also many purpose made metal pots, not to mention wooden barrels and even stoneware available these days. You can, of course, recycle pretty much any receptacle that takes your fancy – old basins and baths are popular choices, but, again, there are no real limits, and remember you can always paint, mosaic or otherwise decorate your chosen container if the shape is right but the colour is wrong.

From a practical point of view there are a few key things to consider when deciding on containers. First off is drainage. I have, on many occasions, come across plants grown in containers with absolutely no drainage holes in the bottom. It sounds obvious perhaps, but not all “pots” come with drainage. Unless you’re planning a bog garden in a pot (which is quite possible, of course) then no plant wants to be sitting in water, and you absolutely must make sure there are good, large drainage holes in your container, which may well mean enlarging upon the holes that are already there.

Ultra chic - architectural Restios.

Secondly think about the stability of your container and the plants you intent to grow. Plastic pots are very lightweight and easily blown over, particularly when they’re housing tall, top-heavy plants. At best this can simply be an annoyance, but at worst you may wake to find your favourite container plant has been smashed to bits in a gale. Taller plants often need additional support, regardless of the weight of the container they are in, so you might want to position near a wall or fence.

As to the compost in the pot, the two key factors are drainage (once again) and body. Different plants will, of course, require rather different recipes of compost, grit, bark chip etc., but in general drainage in any container is much worse than in the open ground, so most plants will require a relatively open compost with fairly large sized particles. This is why clay-based garden soil is not a great choice for a pot – try to water the plant and the whole thing turns into a sludgy mush.

Alpines in an weathered metal trough.

Which brings me to the one downside of container gardening – to have any hope of doing well plants in pots need a whole lot more attention than they do in the ground.

On a hot day in summer containers may well need to be watered twice a day, and even through the rest of the year, including winter, they will need to be kept moist. Rainfall, no matter how heavy, is no substitute for a good soak with a hose or can. You can reduce these watering needs by using a simple automatic watering system, and also by incorporating water-retaining granules into the compost mix.

Proprietary potting composts only have 1 to 2 months food supply built in, so after that it’s all up to you, and most plants will require fortnightly feeding throughout the growing season if they are not to start to look sulky and impoverished. Again, this can be reduced if you incorporate slow release fertiliser granules in the compost mix, but even they will only last for one season, and unless you’re growing annuals then you will eventually have to start a liquid feeding regime – comfrey juice is ideal for veg and many herbaceous plants too.

Plastic sacks make unconventional but effective containers.

The other main factors to consider are about protection, from pests and from the weather.

All of the usual range of garden pests and diseases are equally likely to occur in container grown plants, and a few – notably of the mollusc and vine weevil variety – can be more problematic. Natural slug and snail deterrents consisting of sharp shards can by easily employed on the compost surface in pots and provide an effective barrier. It’s also worth checking under the containers themselves, where you’re likely to find all of the above mentioned little critters will have set up home.

Plants in pots are always going to be more vulnerable to extremes of weather, from hot and dry to cold and wet. Of course the advantage of a container is that often you can simply relocate it to a more hospitable location when weather threatens, but the largest containers may well have to stay put. In winter consider insulating pots with fleece or bubblewrap and, depending on what you’re growing, the plants themselves may require the protection of hessian or fleece tied around them.

Exotica like these tender Cannas make for perfect container subjects.

Heat can be just as damaging, and a dark coloured pot (particularly a black plastic pot) can heat up in full summer sun to the extent that the roots of the plant contained within are cooked and killed. Teracotta is breathable, and provides a much more stable temperature, but even so you may want to consider relocating or shading certain plants and containers for a time.

On balance, though, unless you’re container gardening on an industrial scale, the huge benefits greatly outweigh the maintenance efforts required.

From herbs and fresh fruit right outside the kitchen door, to barrel-fulls of bright seasonal annuals, to tropical wonders on rooftops, to wall-clothing Wisterias and evergreen Clematis on patios, containers are the answer.