Few vegetables and fruit will grow without adequate moisture. Many plants will grow in dry conditions, but they quickly bolt (run to seed) and tend to be tough and often taste bitter. A constant supply of water is necessary so that growth is steady and uninterrupted. Irregular
supplies of water will lead to irregular growth and many vegetables
and fruit, in particular, will split.
Throughout this book there is an emphasis on adding as much organic material as possible to the soil. Once again, this advice has to be repeated. Any free moisture in ordinary soil is likely to drain away or evaporate from the
surface. However, fibrous material around the plant’s roots will hold moisture in the same way as a cloth or a sponge. If there is excess moisture it will drain away, so that the plant is not standing in stagnant water, but enough will be retained to supply the plant’s roots over a considerable time. Even if the water supply depends on irregular rain showers, the slow release will help to mitigate the dry periods.
Working as much organic material as possible into the soil is one way of pre-
empting a dry summer. Add it to the soil when it is dug or, if you are using a non-
digging, deep-bed system, add it as a top-dressing. Do this every year so that the water-retaining quality of the soil improves.
Keeping water in
One way that moisture is lost from the soil is through evaporation from the surface.
Hot sun and drying winds quickly take their toll on the soil and can dry it to a
surprising depth, simply because more is drawn upwards to replace what has been lost nearer the surface. Covering the soil with a mulch helps to preserve this moisture.
Organic mulches are the best ones to use because they not only act as a barrier, but also eventually break down and are taken into the soil, much to its benefit. A mulch acts as a
barrier partly because moisture does not evaporate from it
quite as quickly as it does from ordinary soil, and partly because it acts as a thermal barrier,
preventing the soil from getting too warm and thus speeding up the drying process.
Non-organic mulches – polythene (plastic), for example – prevent even greater loss as little moisture finds its way through, but, of course, it is not as easy for water to penetrate in the first place. Those to whom the aesthetic qualities of the kitchen garden are important may find that polythene looks ugly and will prefer to use an organic mulch.
It is important that the ground is
thoroughly watered before any mulch is applied. If the ground is left dry the mulch will prevent it from getting wet unless a
very large quantity of water is supplied.
Water is an expensive commodity – and becoming increasingly expensive in some areas – so you should use it only where and when it is really needed. Avoid, if possible, using sprinklers that waste large quantities of water on paths and other non-productive ground. If you have the time and strength use a watering can, supplying water to the base of individual plants. If you do this, you can be sure that the water goes where it is most needed. Sprinklers are especially useful when there is a large area of produce to cover or if watering by hand is difficult for physical reasons.
One efficient way of supplying water is to use a drip hose. This is a hosepipe (garden hose) with holes in it. It is laid along the line of plants and water constantly dribbles out. There is not enough water to flood the soil, but there is sufficient to provide a constant supply to the plants. If the ground is mulched, lay the pipe under the mulch. These hoses are best left on for several hours until the soil has taken up sufficient
moisture, and then turned off, but there
are gardens where they can be left on
permanently. The system works best with permanent plantings, such as fruit bushes.
Whatever method you use, make certain that the ground is thoroughly soaked. A sprinkling of water on the surface will do
little other than lay the dust. To be effective, a watering should supply at least the
equivalent of 2.5cm/1in of rain.