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Watering vegetables
Although vegetables usually need to be watered for the best crops, some can give acceptable results with minimal extra watering. But sowing and transplanting are critical times for watering for all crops.
Sowing
Ideally, thoroughly soak the soil and allow excess water to drain, before sowing. Where this is not possible, dribble water at about 1-litre per 30cm of row (1.75 pints per 1ft), into the drill before sowing. Sow on the moistened soil and cover with dry soil. Avoid watering after sowing as this can pack the soil down and prevent emergence.
Transplanting
Ideally water before transplanting and again after planting and again a few days later. Where preliminary watering cannot be given, use a trowel to excavate a hole big enough to comfortably accommodate the transplants’ roots, place the transplant in the hole, and repeatedly fill with water until the surrounding soil is saturated; this takes 1-3 litres (1.75-5.25 pints).
After planting
Subsequent watering is given every 10-14 days in dry weather to supply enough water, 25-litres per sq m (5.5 gallons per sq yd), to sink deep enough into the soil to wet to about 25cm (10in). To save water and effort watering may, in some cases, be targeted to when the vegetables are at certain growth stages.
- Some leafy vegetables, such as spinach and celery for example, produce more and better quality and are less likely to run to flower if kept moist at all times.
- Cabbages, cauliflower and lettuces are similar, but applying 25-litres per sq m 10-20 days before harvest gives good results if water is short. Brussels sprouts benefit from watering when the buttons begin to form.
- Flowering legumes and sweet corn respond to two soaks (or every 10 days) when flowering begins and when produce begins to form. Watering at other times promotes foliage without increasing yield. Runner beans, courgettes and cucumbers have a prolonged flowering period and need constant moisture and repeated watering to do well.
- Root vegetables are not so needy of water as other crops, but benefit from watering, especially when grown densely.
- Onions show little benefit from watering.
- Potatoes do best when water is plentiful. But if pressed, concentrate on tuber initiation, usually in May, to boost tuber numbers, and during late summer to limit fluctuations of soil moisture that lead to splitting and secondary tubers.
Vegetables grown in closely-planted bed systems usually need more water than vegetables grown further apart in rows.
Growing crops in pots
For information on this topic visit the BBC gardening website