Sweetcorn

Overview

Sweet corn -  Zea maya                           Rotation group – Others

Sweet corn, or more accurately maize, has been in cultivation for thousands of years. Sweet corn itself is a much more recent introduction and has now become established as an allotment crop. The earlier introductions had a reputation for losing their flavour very quickly - literally within hours; but the more recently introduced super-sweet varieties of sweet corn are able to keep their flavour for several weeks. Sweetcorn prefers warm growing conditions but once again the plant breeder have been busy and now there are hardier, quicker growing and maturing selection available in the catalogues.

Never grow supersweet and non-supersweet cultivars together because they will cross pollinate and the pollen from the non-supersweet will damage the quality of the supersweet cultivars.

How to grow

Sow

Sweet corn is best grown from seed that is sown during April- May under glass. It can be sown outdoors in the warmer parts of the country but it always carries the risk of poor or slow germination. Two seeds are sown 2.5cms/1ins. deep in 10cms/4ins. pots containing fresh seed or potting compost. After germination the weaker of the seedlings is cut out. It is best to cut rather than pull because sweet corn resent any form of root disturbance.

Grow on

Choose a sunny, open site where the soil has been manured before-hand. The plants must be prepared for planting outdoors by hardening them off over a couple of weeks. As soon as the roots begin to reach the bottom of the pot the plant is ready for transplanting into the open ground. Because sweet corn is a member of the grass family and is wind pollinated it has to be planted in blocks to be sure that the female flowers are fertilised. The individual plants should be set out at 75cms/ 2ft 6ins spacings and may still need protection against cold weather or late frosts.

Aftercare

Keep the developing plants well watered and hoe regularly to keep the soil between the plants free of weeds. The plants will need the support of a stake to prevent wind rock blowing the plants over. Draw soil up around the base of the sweet corn plants to increase the root system and to help support them against wind rock.

How to Harvest

Harvesting

Harvest from late August onwards when the tassels at the ends of the cobs have turned black. At this stage gently peel back a small part of the husk coating to reveal a few of the seeds. Press your thumbnail into a plump corn seed and if a milky substance squirts out the cob is ready for harvesting. If the juice is not milky wait a few more days and re try the test. Harvest the cob by gently easing it downwards until it snaps cleanly away. The cob can be stored in the refrigerator for three or four days before using.

Issues

Pest and disease

Thankfully sweet corn is trouble free in the UK apart from being attack by rats who can devastate a block overnight.