Growing Sweetcorn: Care and development
Sweet corn is well able to smother mostwhen growing vigorously and approaching maturity, but in the early stages it often grows slowly, especially during dry weather, and is then very vulnerable to weed competition. Either hand-weed, or hoe lightly to keep weeds down, remembering that corn has a very shallow rooting system and over-vigorous hoeing can do more harm than good. Keep the plants well watered, particularly in dry weather. Do not over-water, however as this will lead to lush foliage at the expense of cob production.
Liquid feeding is beneficial, at regular intervals from pollination time to harvest; the kinds of liquid fertilizer used for tomatoes are suitable. If the corn appears to stop growing when it is about 30 cm (1’) high, and the leaves turn yellow, apply a quick-acting fertilizer, such as dried blood, at the rate of 5 ml (1 teaspoonful) per plant.
Some gardeners carefully earth-up theirplants, as with , to a height of about 20 cm (8”) when the plants are about 1.2 m (4’) tall. This encourages the production of more roots. A mulch of straw applied in midsummer will retain moisture and also keep down weeds. Some gardeners remove the sideshoots, but this practice seems not to have any beneficial effect.
Harvesting and aftercare
A common mistake is to leave the cobs on too long before harvesting. In general, cobs will be ready for harvesting about three weeks after the silks have appeared on each plant. To determine when the cobs are ripe, watch the silken tassels on the cobs. While the grains are growing thay are moist and pale green. When ripe, they turn dark brown but still remain damp. If they become dry and shrivelled, they have been left too long. The sheath of the cob should be dark green and on no account be left to turn yellow or faded brown.
You can test one of the kernels for readiness by piercing it with a thumb- nail. If creamy ‘milk’ spurts out, the cob is ready for picking. If the liquid is watery, the cob is still unripe, and if little or no moisture emerges, it is over-ripe. Normally, when cobs are left too long on the stalk the sugar they contain will begin turning into starch. Because the conversion from sugar to starch takes place as soon as the cob is parted from the parent plant, you should pick the cob no more than half an hour before it is to be cooked. However, certain varieties of sweet corn have been developed which improve, rather than deteriorate, for a few hours after picking. These extra-sweet varieties should not be grown near other varieties, as cross-pollination will affect their flavour.
To pick a cob, grasp it firmly and split it downwards from the stalk. It should break off easily. Take the big cobs from the bottom first, so the plant channels its energy into the smaller cobs further up the stalk. Cobs on the same plant will ripen at intervals of a few days, but unless it is an exceptionally hot, dry summer, you are unlikely to get more than two fully grown cobs per plant.
Unlike field corn (or maize), which can be stored in a dry place for indefinite periods, sweet corn is harvested while succulent and is best used almost immediately (or prepared for freezing) although it will keep for a few days if stored in a cool, moist place. Do not remove the husks until you are ready to cook the cobs.
The dry stalks of sweet corn after harvesting form a kind of straw which can be used as litter for domestic animals. Alternatively break up the stalks with a sharp spade, and put them on theheap.
Ripe corn has dark brown, damp tassels; those on overripe corn are dry and shrivelled (top).