The watertight solution

With little rain forecast for the next few weeks, Anna Pavord offers a guide to keeping plants happy in dry weather
Click to follow
The Independent Online
Like a cow just coming into milk, the sky has at last squeezed out the first drops of rain. Well, I thought to myself, at least the system still works. For gardeners, the lack of rain has been an inconvenience, but it is not a disaster, as it is for farmers who have fields full of lambs and no grass to put in front of them.

When water was a public utility I felt I ought to do something to help in a drought: put a brick in my loo, cut down the number of showers I took, rig up some system to save rainwater, even siphon off the bath water to reuse on the flower borders. Privatisation has changed all that. While those who run the water companies pay themselves so handsomely for wasting a billion gallons of water a year in leaks, I feel less of an urge to help them with their problems.

At least the Conservatives saved themselves the embarrassment of a Minister for Drought. The last one, Denis Howell, was put in place by the Labour government after the exceptional drought of the summer of 1976. Within days of his taking office, it rained floods.

That summer environmentalists were predicting the end of the world as we knew it. Because of that drought, we lost a big beech tree in the garden. I still miss it, but it was old, and the following autumn we planted another three to take its place. In the long term, the rest of the garden was unaffected by the lack of rain.

If gardening teaches you anything, it is the importance of the long view rather than the short. We have to hang on to that thought. Style merchants treat flowers like scatter-cushions to be strewn here and there where the colours will make a good photo-opportunity for the next snapper who happens to be passing through. If the flowers die, as they tend to when their owner's requirements are put before their own, no matter; there are more to be had at the garden centre. Garden centres market plants like cans of beans.

The long view on drought is that, compared with Somalia, we don't know what it means. That said, there are plenty of things real gardeners can do to help their plants through the next prolonged spell of dry weather. The crux of the matter is the soil. If you get the soil right, the plants will look after themselves. Plants in pots, hanging baskets, growing bags or other unnatural places will always need more water than plants in open ground. Pots in sun dry out more quickly than pots in shade.

On thin, fast-draining ground, the more bulky stuff you can get into the ground, the better it will be able to hang on to what moisture there is. Think of compost, muck and leaf mould as blotting-paper. Soil needs organic matter like this. Nature keeps trying to provide it, but we, as gardeners, keep clearing it away. The easy way to get blotting-paper bulk back into the soil is to lay on thick blankets of mulch through the autumn and winter, when the soil is already damp, and then let the worms drag it into the soil for you. Getting the soil into good condition is the single most important thing that gardeners can do to combat drought.

We should also ask ourselves whether it's our fault or the water companies' that April-planted trees and shrubs die for lack of water. For growing things, the recent lack of rain has been aggravated by lots of sunshine and some searing winds. Until the advent of garden centres with their container-grown plants, the general time for planting trees and shrubs was the autumn. It is still the best time. Most trees and shrubs are dormant then, although roots continue growing until the turn of the year, when the soil temperature drops.

With no top hamper to worry about, plants can concentrate on getting their roots sorted out, getting the browsing and sluicing systems in place before spring, when everything happens at once. This April, leaves emerged earlier than usual, and newly planted trees and shrubs have been losing water by transpiration more quickly than they can pull it up from roots that have had no chance to make close contact with the surrounding soil.

If you plant in autumn, you can get hold of bare-rooted trees and shrubs, dug from open ground, which will have far better root systems than anything grown in a pot. Well-developed roots, snuffling about in well-cared-for soil, will be a plant's best defence against drought.

Container-grown plants are generally raised in soilless compost. That's another problem. After their easy life in the open texture of a soilless compost, plants sometimes can't be bothered to attack the real stuff. They just wander about in the increasingly crowded and starved confines of the pot-shaped bit of compost you have planted, and fail to develop a system capable of keeping up with the rate of growth on top. But if they have never been used to the easy life, they won't miss it.

Loam-based composts hang on to moisture (and nutrients) better than soilless ones. They are not as popular, because they are much heavier to hump about - and if you live three floors up in a building without a lift, that matters. If you don't, use loam-based compost for your containers. Water-retaining granules such as Swell-gel help, too. I now use them as a matter of routine when I am planting up pots for the summer.

In a survey carried out by Gardening Which?, readers said that the most common casualties of drought in their gardens were camellias, azaleas and rhododendrons, growing in containers. That is scarcely surprising. Those acid-loving shrubs have surprisingly compact rootballs. That isn't a problem if they are growing - as nature intended them to be - in a woodland setting. There, a mulch of thick leaf litter prevents moisture evaporating from the ground. Overhead trees provide shade and shelter so that the foliage of the lower-growing shrubs is not dried out by sun or wind. Perhaps we should be asking ourselves whether we should risk the lives of such shrubs by growing them in containers, rather than complaining when they die.

The worst casualties of drought are usually vegetables. This is because, to be a success in our terms, to be fat and succulent, they need to grow with as little competition as possible from other plants. We have to keep them well weeded, which means there is an awful lot of bare soil round them. Bare soil dries out much more quickly than soil that is covered with the leaves of plants. That sounds paradoxical, when you think of the amount of water plants take up from the soil. But it's true, as you would know if, during the dry weather, you were to slip your hand under a fat clump of ground-hugging pulmonaria and feel the cool, moist soil underneath.

When vegetables such as lettuces, peas and courgettes are well established, plant marigolds and nasturtiums to blanket the ground around them.

And ponder on the fact that there was scarcely a heart-beat between shock! horror! reports of the drought and complaints about rain stopping play on the cricket field. DROUGHTBUSTERS

1 Add organic matter to the soil

2 Mulch

3 Plant trees and shrubs in autumn, not spring

4 Use loam-based compost

5 Use water-retaining granules in containers

6 Match plants to positions

7 Soak container-grown plants before planting

8 Buy a rainwater butt