It used to be difficult to get a good crop of sweetcorn in Britain, but in recent years a new breed of modern F1 varieties has been bred for cooler climates.
Their hybrid nature makes them more vigorous and willing to crop. It also improves germination, which was always a problem here, so always opt for a modern F1 variety of sweetcorn.
Some are listed as supersweet and some tendersweet. The tendersweet varieties can be eaten raw, but both stay sweet after picking because the sugars are slow to turn to starch.
When to plant
Sow sweetcorn seeds in early April and plant out after mid-May, once the fear of frost has passed, after mid-May.
Where to plant
Plant sweetcorn in a sunny, warm position that isn't too windy.
How to plant
Sweetcorn loves warmth, but it has brittle roots and dislikes being transplanted. Luckily the seeds are large enough to handle so it’s easy to sow them individually, either into plant modules or small pots.
Almost fill the pots or modular trays with seed compost. Place one large seed in each. Water well and keep the seeds warm: then they should germinate within two weeks.
Once the individual plants are four to six inches high, harden them off for a week outside and then carefully plant them out. Late May and early June are the best times. By then it’s warm enough for the plants to thrive.
Plant carefully, leaving 18 inches (45 cm) between plants, preferably on fertile ground. Water thoroughly after planting out and right through the growing season to encourage large cobs.
Don’t plant them in rows. Put your sweetcorn plants in a block because these wind-pollinated plants need to be close together so that the pollen travels downwards between the male and female flowers in order to produce cobs.
Tap the plants every time you pass them in the early stages to distribute the pollen. Avoid windy situations as the pollen may be blown away and always plant one variety to prevent inferior 'hybrid' cobs being produced.
When to pick
Harvest sweetcorn once the beard (the hairy bit at the top) is brown. If in doubt, squeeze the cob. If a milky liquid oozes out, it's ripe.
Modern F1 sweetcorn varieties
A pleasure to eat, this tender mid-season variety produces thin-skinned, golden kernels even in the coldest gardens. A consistently high performer.
A mid-season variety known for producing the largest tendersweet cobs.
An early variety with golden kernels.
'Marei Yellow F1'
Fat bright-yellow cobs full of flavour and this one can be eaten raw or cooked. Vigorous, even in poor soils, with fully packed cobs.