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Sweetcorn

Zea mays

INTRODUCTION

A vegetable (technically a grass) that heralds the first signs of late summer, Sweetcorn, also known as Maize/Corn-on-the-Cob has been in cultivation since 7000BC.

A beautifully architectural plant which can double as a windbreak, this kitchen garden favourite should really be on every grower's schedule. Sweetcorn is quite greedy for space on the allotment but relies on others for pollination - it's an easy crop to grow as long as it's not on it's own. Why not make some space on your plot for some Sweetcorn!

Soil Preparation

The site should be sunny, sheltered and away from prevailing winds.

For the very best crops, the soil should be deeply cultivated, rich, fertile and moisture retentive.

Add plenty of well-rotted organic material the autumn before planting.

If the growing site is exposed, consider growing the shorter available varieties.

Prepare the ground by removing any weed from the soil and rake level to a fine tilth.

Sowing & Planting

Sweetcorn is not frost hardy and sowing or planting should only be carried out when all risk of frost has passed.

Sowing can be made directly in situ but sowing under cover in pots or modules is a more reliable method.

Soak seed overnight to soften the outer shell.

Sow seed into multi-purpose compost and keep at a temperature of 15-20oc.

Keep seedlings well watered and harden off before planting out.

Early undercover sowings can be made from mid-April onwards with direct sowings made from early May weather permitting.

If direct sowing in situ, sow 2 seeds per plant station and thin to the strongest plant when large enough to handle.

Sowing/planting should be made at 45cm (18 inches) between plants and rows. Sweetcorn benefits from growing in a block rather than individual rows, to aid pollination. Poor pollination will result in substandard yields.

Growing & General Cultivation

Keep plants weed-free by regular hoeing but ensure plant bases are not loosened.

Support plants if necessary with stakes or canes and string, particularly in exposed areas.

During dry weather, water plants well to keep growth active. Mulching will help to conserve moisture.

If the ground has been previously well manured, further feeding should not be necessary. If foliage starts to turn yellow, apply a liquid feed every 2 weeks.

Pests & Diseases

Sweetcorn is relatively pest and disease-free. The odd issue may arise:

Mice may dig up directly sown seed. If this is a problem, set traps or raise plants in pots.

Slugs and Snails can be a problem for young plants in the early stages of growth, especially with direct sown crops. For remedies - see Product Directory.

Frit Flies will cause yellow stripes on the foliage. Foliage may also become distorted. Crop devolvement will be poor with minimal yields.

Sweetcorn Smut can affect cobs during periods of very hot and dry weather. Kernels turn pale grey and spill black fungal spores. Remove affected cobs and avoid growing Sweetcorn on the same site for 4-5 years.

Badgers and Squirrels are very partial to the cobs as they reach maturity. Be on your guard.

Harvesting

Sweetcorn is not the quickest of maturing allotment fruit and veg.

Maturity is reached when the tassels hanging out of the top of the cobs turns brown after approx 12-16 weeks from planting.

Before cropping, peel back some of the foliage and test the firmness of the individual kernels. They should ooze a milky liquid when ripe.

Do not allow to over ripen, kernels will become tough and inedible.

Harvest cobs by pulling downwards.

Sweetcorn should be eaten as quickly as possible after harvesting as the plant sugars immediately start turning to starch and flavour will deteriorate.

Sweetcorn does, however, freeze very well.