Irrigation: Watering Your Garden
By Alex N •
What is the best way to water my garden?
It might seem obvious that all plants need water...but why? and what is the best way to water my garden Plants need water for many reasons. Seeds will not germinate without water and plants can only use the nutrients in the soil if they are in soluble form. Water gives the plant its shape and stiffness; without it the plant becomes limp.
If the water loss becomes too great the stomata (holes) in the surface of the ‘skin’ close and the basic plant processes come to a halt. You must, therefore, ensure that plants always have enough water for all their needs.
During dry weather you must give your plants the water that nature has failed to provide. The most common mistake, however, is made of watering irregularly and in insufficient quantity.
It is essential to give enough water to penetrate the soil down to the layer where the plant roots are growing. If you only sprinkle the surface, the water will simply evaporate in the heat of the sun.
How much water?
Apply sufficient water to penetrate the soil to a depth of at least 15cm (6 in) - preferably more. This means applying at least 2-3cm (1 in) of water, depending on the soil type. The lighter and more sandy the soil, the deeper this amount of water will penetrate.
If you are using a sprinkler, you can measure the amount of water being applied by placing a number of tin cans over the area being watered. When there is 2-3cm (1 in) of water on the bottom of the tins you will know it is time to turn off the sprinkler.
If you water with a hosepipe then you will have to dig down into the soil with a hand trowel to see how far the water has penetrated.
Start watering before the soil dries out to any great depth; a good guide is when the top 2-5cm (1-2 in) is becoming dry. In hot, summer weather you may have to water at least once a week.
It is usually best to apply water in the evening, as then none will be evaporated by the sun and it will penetrate the soil to a good depth.
Many people do not realize that wind is a major drying agent (especially in spring and early summer), so watering will be necessary after windy weather.
Sprinklers and hoses
Applying all this water will be very time- consuming if you have to rely on a hosepipe alone. It is therefore a good idea to attach a sprinkler of some kind to the end and let it automatically distribute the water.
There are many types on the market to suit all pockets. The cheapest are those with no moving parts (mini-sprinklers), but which produce a fine circular spray from a static nozzle. Often the base of these is equipped with a spike which you push into the ground to hold the sprinkler firmly.
Rotating sprinklers are slightly more expensive. They have two adjustable nozzles on an arm which is spun round by water pressure, giving a circular pattern. These are probably the most popular for private gardens.
The more sophisticated oscillating sprinklers apply water in a square or rectangular pattern. A tubular bar with a row of nozzles (non-adjustable) moves backwards and forwards, watering a very large area. It is worked by water pressure. Some can be adjusted to water a small or large area.
My personal favourite is the sprinkler hoses or weep hose which is often referred to as drip irrigation. These are perforated plastic or rubber hoses of various kinds which are connected to the main hosepipe and produce a gentle spray of water along their complete length.
One of these can be laid along rows of crops, or between plants. they are very economic with the water applying it only where is is needed.
You will, of course, want a good reinforced plastic or PVC hosepipe; a 13mm (1/2 in) diameter hose is a suitable size for general use.
Watering vegetables
Most vegetables benefit greatly from regular watering, especially crops like runner, French and broad beans, peas, marrows, lettuce, radish, cucumbers and tomatoes.
Vegetables such as cabbages and other green stuff, and root crops like potatoes and carrots, can get by without regular watering, although their yields will not be so heavy.
All newly-transplanted vegetables must be well watered in if the ground is dry and then kept moist until established. You can water these individually with a watering can.
Seeds must be kept moist to encourage them to germinate. This is especially true of the modern pelleted seeds, which will fail to grow if they lack sufficient moisture.
Fruit trees and bushes
Fruit trees, provided they are well established, will not come to much harm if you do not water during dry spells, but the fruits may be smaller than normal. However, black, red and white currants, raspberries, strawberries, gooseberries, blackberries, loganberries and other hybrid berries really do need watering in dry weather if they are to crop well.
Flowers in beds and containers
It may not be possible to water everything in the garden, especially in a very dry season when there may be restrictions on the use of sprinklers in the garden. If this is the case, the flower garden must take third place - after fruit and vegetables, which you will be growing to supplement the family budget.
However, flowers in containers (such as tubs, troughs, hanging baskets and window boxes) will soon die if not watered regularly. These dry out rapidly in hot weather and may well need watering twice a day - in the morning and again in the evening.
Watering the lawn
I am not an advocator for watering lawns as I consider it wasteful. Lawns rapidly turn brown in dry weather, but they will green up again very quickly once the rains start.
To keep a lawn green in the summer you will need to begin watering before it starts to turn brown and continue at weekly intervals, or more frequently, thereafter. Remember also not to cut a lawn too short in dry weather - so raise the mower blades.
Mulching the soil
There is a method of conserving moisture in the soil which will enable you to cut down on watering. It is known as ‘mulching’ and consists of placing a 5-8cm (2-3 in) layer of organic matter around and between plants - covering the root area.
Use garden compost, well- rotted farmyard manure, leaf mould, spent hops, straw, grass clippings or bark chip.
Another method, is to use black polythene sheeting. To anchor it to the ground, bury the edges in ‘nicks’ made with a spade in the soil; then place a few stones or bricks on top. You can buy rolls of special black mulching polythene.
All plants benefit from being mulched, for moisture is conserved and so they do not dry out so rapidly. If you have to limit mulching, however, then concentrate on your vegetables and fruits, rather than on your flowerbeds.
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