Watering Crops in Dry Weather

Watering Crops in Dry Weather

May was a wet cool month as everyone probably remembers – excellent for planting out, digging, weeding and working with the ground – when we could find a short spell when it stopped raining long enough for us to work our plots. But, growth was a bit slow, waiting for some sunshine and heat.

In June we have definitely had that. Growth is rampant, especially with soft fruit of all types that the birds have left alone. I have had to be away quite a lot lately and find, on my return, that my soft fruit crops are way ahead of my picking and using ability. My sugar-snap peas are almost too mature and my summer brassicas – Romanesco and purple cauliflower have headed up but without the water they needed to provide good heads. Most of a bed of Little Gem lettuces have just gone beyond looking their most attractive though I might still be able to salvage some.

I still have some beetroot and winter brassicas in pots waiting to be planted out but, the ground is now too hard and unworkable to plant them. I might have to water the ground well in the beds to be able to plant them out - then water well over days to ensure they have established.

I have a large plot and a poly-tunnel and find that I really must restrict the amount of watering I do. We are not allowed hose-pipes on our allotments but must carry water from fixed points throughout the fields. This can be demanding and very physical work. As I have a poly-tunnel, growing crops which do require water, it is important that this is my first priority. I could choose to water directly onto the root areas of the plants and leave the rest of the ground dry. However, red spider-mites can be a problem. These determined little pests don’t like moisture so I choose to water all of the surface and the paths to discourage the mites which do come in to my tunnel and can move from plant to plant unless discouraged.

If I had lots of energy and unlimited supplies of water I would slosh loads of water around my summer brassicas as they are hearting up and around my peas and runner beans and French beans as they are putting on their flowers and developing pods.

I am watering recently transplanted seedlings and my courgettes, cucumbers and winter pumpkins. The courgettes are now setting, the cucumbers are developing and the winter pumpkins are just putting up their first female flowers – some of them look as though they need some extra water.

I’m not too worried about my runner beans. This year I have planted them around tepees rather than in rows. I have found that, as my plot is on a slight slope, as the season progresses and the plants become heavier, my rows of canes start to lean determinedly downhill. I have chosen to plant them in my no-dig area which has had a good mulch of manure each year for several years. In the last few years I have followed my now naturalised flower bulbs with winter pumpkins, squashes and courgettes. I thought, this year,  it would be a good idea to have a change of crop. Well manured and composted ground will definitely hold onto moisture much longer than ground which lacks humus.

Suggestions:

·        It is important also, to keep weeds off the planted beds as the weeds will compete with your crops for the available water. Although it would seem that the weed cover is keeping the moisture from evaporating, really, those weeds which are probably more at home on your ground than the crops you plant, will take the best nutrients and moisture. Hoeing is good in dry weather, if you can get the hoe through the ground. The decomposing weeds will be a mulch to help keep the moisture in. In wet weather, hoeing is not so useful as the weeds move over and re-root

·        Lots of humus in the soil helps to hold onto the moisture in dry weather. Add manure, either as a mulch in autumn or early spring and dig in well or, in a no-dig bed, add in the autumn and let the worms take the humus into the soil. I have, in the past [and will probably continue to do so, put lots of well rotted manure around my fruit bushes, trees, canes etc. in autumn and early spring to feed them and to act as a mulch. However, I have found that birds – crows, magpies, blackbirds, robins, pigeons, remove it looking for insects and scatter it everywhere but under my bushes.

·        Do think about the response of the plant you are watering to the water you are putting on it.

·        Do think about the amount of energy you expend and water used watering plants which may not need watering.

·        Remember that watering encourages leaf, stem and flower growth, for root crops this is not necessarily what you want.

Water is one of the essentials to make plants grow and most gardeners assume that keeping vegetables well watered will pay dividends. In fact, this is not always the case and excess water can result in rotting, leaching of nutrients, poor taste and poor keeping qualities, especially in onions and garlic.

All vegetables need water to start with, either from seed or when planted out. After this establishment phase is over, they usually grow very strongly and push roots wide and deep, 2 feet or more is common. This is usually early season when water is freely available in the soil and extra watering is totally unnecessary and can result in a weak root growth (with a poor subsequent performance) or the production of large amounts of something you don’t want – foliage on peas, for example. When the plant has grown, the onset of flower and seed formation, which is often the product you do want, means that the plant’s emphasis changes to the production of these and root formation stops. It is at this time that many plants need extra water and they respond very well if you apply it.

Watering technique is also important. Roots are usually deep and you need impractically large quantities of water to get enough down there. The only way to help the plant is to target the roots – light sprays over the foliage or wetting ground are useless. This targeting is assisted if you build in depressions in the soil around the plant (peas/beans) or bury a bottomless bottle next to the plant roots (tomatoes). Many will find the extra hassle of these measures not worth the effort [like me – I have 5 ridges of peas and three tepees of beans. I feel they must take their chances with the weather and, so far this policy has worked well]

See the table below for the optimum and necessary times for watering you crops:

Category 1  - Responds well to frequent watering

Category 2  - Water only at sensitive stages shown

Category 3 -  Not very responsive, water only as advised

 

Category 1 - Responds well to frequent watering

·        Aubergines, peppers and chillies – high maintenance plants which require lots of heat, moisture and food – water twice daily. [I wish! Mine are watered when it suits me, every day if possible though I do give them a good drenching when I do water].

·        Summer cabbage and calabrese – most efficient is one watering 2 weeks before cutting

·        Cauliflowers - most efficient is one watering 2 weeks before cutting.

·        Lettuces – throughout their life.

·        Courgettes and other curcurbits [cucumbers, pumpkins, melons, squash, gourds] – frequently once flowers and fruits form.

·        Spinach/ Swiss chard – frequently.

Category 2 - Water only at sensitive stages shown.

·        All beans – when flowering and throughout pod formation and development.

·        Peas - when flowering and throughout pod formation and development.

·        Potatoes – when flowers start to form and potatoes are the size of marbles – for many plot holders this can be a large area [ I never water my potatoes, whatever the weather].

·        Sweetcorn – at tassle and cob formation.

·        Tomatoes – when flowering and setting fruit, be careful to not over water as this will affect the flavour.

Category 3 - Not very responsive, water only as advised :

·        Beetroot – water before the soil gets too dry.

·        Broccoli [winter] – water well after transplanting to ensure the plants have established.

·        Brussels Sprouts - water well after transplanting to ensure the plants have established.

·        Carrots – before the soil gets too dry, just along the rows.

·        Curcurbits [ cucumbers, squash, pumpkins, courgettes, melons] – water well but slowly to allow the water to penetrate to the deep roots, perhaps once a week. Avoid water on the leaves to prevent disease. But frequently once the fruits form.

·        Garlic and onions – do not water in the later stages but, for spring onions water just along the rows.

·        Leeks – after transplanting to ensure they have established.

·        Parsnips – water just along the rows before the soil gets too dry.

·        Radishes – water just along the rows before the soil gets too dry.