The Importance of Watering Vegetable Plants
Watering Vegetable Plants
The natural companion to feeding plants is, surely, watering them. Of the two, watering is certainly the more important; a plant can live for quite a long time without food, but can be dead after a couple of days without water. This isn’t very surprising when you consider that about 75 per cent of the weight of a living plant is water.
There used to be a belief, there may still be, that once you start watering the garden, you have to carry on until there’s a really good downpour. This is a time-honoured tradition often perpetuated by older gardeners. It’s nonsense and yet, like so many of these old beliefs and sayings, there’s a grain of truth in it; or rather, it can frequently be based on a half-truth.
The normal drill for a new gardener, when they see that things are getting parched, is to go out into the garden with a watering-can and make it go as far as possible. This usually results in the water soaking in an inch or two at the very most; usually it just lays the dust.
Under dryconditions, plants tend to put out new roots into the soil which is the moistest. Under the above watering conditions, this is on the surface — and it is this surface layer which is the first to dry out when the sun comes out again. Unfortunately, this is the layer where all the young roots are and, without water, they’ll simply shrivel up. You therefore have to keep on watering to ensure that this surface soil remains moist, hence the origin of the belief.
If you water properly, however; and give enough for it to soak down a good 6in (15cm) or so, the problem won’t arise because the roots won’t be duped into growing only near the surface in the damp earth. Also, the soil will stay damp for much longer and, even in the driest conditions, you could well get away with watering only about once a week instead of every day.
Incidentally, the idea that it’s best to water in the evening as opposed to the morning is largely correct. It’s much cooler at night and the plants are under far less stress. This means that they’ll be able to take their time absorbing water and, by the morning, will have taken up all they can hold. Also, the water will have a chance to soak down into the soil and won’t just evaporate the moment it hits the soil.
Timing and Quantity
Quite a lot is known about the water needs of vegetables as, being an economic food crop, a lot of research has gone into it. Not only do we know how much water a particular crop needs but we also know the times during its life when water is most important and when a shortage is going to be most damaging.
Here are a few examples. Peas and beans need plenty of water when they’re flowering and again when the pods are swelling. Root crops, such as carrots,, and , need a steady supply throughout their life to maintain even growth. If water is available in fits and starts, it simply leads to surges of growth and the inevitable splitting of the root. Much the same applies to tomatoes.
With, a thorough soaking when the young tubers are about the size of marbles is the most beneficial, though here again they should never be allowed to run short. If they are, growth will stop temporarily and, after a soaking, it will start again. This doesn’t always lead to splitting but to a phenomenon known as ‘second growth’ when lumps and bumps and odd protuberances grow out from the tubers. Grand for children to make animals from but pretty useless as vegetables. Plenty of water for early potatoes also means that they can often be lifted earlier; when they are at their most expensive to buy.
Brassicas, celery and other ‘green’ vegetables, such as lettuces, usually have a critical time in the last couple of weeks or so before they’re ready to be gathered. Keep them well watered then.
Radishes, summer turnips andshould always be grown fast with plenty of feed and water or they’ll go woody; radishes will often bolt as well (send up a flower stem).
If summer and autumnget any more than a slight check to their development, it invariably leads to the curds bursting and running up to flowers when they are still quite small. Calabrese is the same.
On the whole, there isn’t a single vegetable that actually likes to run short of water; the best that can be said is that some will tolerate it better than others. By the same token, none like to be waterlogged for any length of time either.
The next point we have to consider is the amount of water that should be given at any one time. We’ve seen that ‘a little and often’ is worse than a waste of time because it does the plants more harm than good. Washing them out of the ground is equally bad.
When you water, give at least half an inch (1.5cm) and preferably an inch (2.5cm). If you’re using a sprinkler, this is easy enough to measure. Stand a few empty tins on the area being watered and measure the water that collects in them until it’s reached the amount you want. If you can guarantee turning on the tap to the same point every time, you can see how long it takes to deliver the required amount and make a note of it for next time. You have to be fairly accurate though.
A much better way is to attach a water meter to the tap and run the hose from that. Don’t worry, these can be bought for a reasonable price. It will measure out any quantity you like from about 15 to 420 gallons simply by the turning of a dial. When the set amount has been delivered, it automatically cuts off the supply — couldn’t be easier.
Small areas, such as single rows and the like, can either be watered with a handheld hose with a rose on the end, or a watering can. With the hose it isn’t always easy to judge the amount of water you have given, but with a can you’ll be able to work it out on the basis of I in of water for 1 sq.yd being about 13 pints.
Here are a couple of other useful figures: 1 in over 50 sq.yd is roughly 230 gallons. Four gallons per sq.yd are needed to soak 1 ft deep into medium loam.