Sweet Corn

Common name: Indian Corn / Maize

Sweet corn is a hybridised variety of maize, bred to increase the sugar content.

The cobs are picked before the fruits mature into hard grains, and are generally eaten as a vegetable.

Sweetcorn is wind pollinated and best planted in groups / blocks.

This method ensures that the pollen from the male flowers at the top of the plant shed their pollen on the female tassels /silks below them.

Subject to variety, each plant will produce one or two cobs.

Care should be taken when choosing varieties, as sugar enhanced varieties should not be grown alongside non enhanced varieties to prevent cross pollination.

To do so would defeat the object of growing the two types.


Week 15: Prepare beds now if not done the previous autumn, by digging in liberal amounts of well rotted manure or compost.

Week 17: Sow seed in pots/trays of seed compost and germinate at a temperature of 18°C (65°F).

Germination should take about four or five days.

To assist germination, soak seed in clean water for twelve to twenty four hours prior to sowing.

Week 18: Prick out seedlings when they are about 75mm (3") tall into 75mm (3") pots of potting compost, and gradually harden off in a frost free cold frame until planting out time.

Sowing directly into fibre pots elimiates the need to prick out.


Sown in Cells


Pricked Out


Sown in Fibre Pots


No need to Prick out.

Week 22: Plant out in blocks/groups in pre-prepared soil, 400-500mm (16"-18") apart both ways in a sunny sheltered location.

Apply a top dressing of a balanced fertiliser at a rate of 100gms (4oz) per sq. m prior to planting.

Planted Out

Growing On


Flower Stage


Week 29: Apply a top dressing of high potash fertiliser.

Week 30: Keep weeds down by hoeing, taking care not to damage the surface roots.

Water regularly during the flowering period, and as the cobs begin to swell.

Lay a mulch of garden compost or straw, to reduce water loss from the soil.

In exposed areas ensure that taller varieties are supported, although the block formation they are being grown in results in them supporting each other.

Week 33>: Check the plants regularly and harvest the cobs as they ripen.

The cobs are ripe when the silks protruding from the end are dark brown.


Cobs Developing


Ripened Cob




Corn on the Cob

Do not allow the cobs to get over-ripe, as this inclines to make them starchy and less palatable.

Another sign of ripeness is the milky juice that exudes from the kernels when pierced by a fingernail.

Eat or freeze as soon as possible after picking.

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