Advice
RHS Help & Advice
Growing sweet corn
Home-grown sweet corn is delicious cooked the moment it is harvested. Choose new, improved cultivars that have been developed for sweetness, flavour and tender skins.
Sweet corn cultivation
Outdoors, sweet corn should be sown every two weeks from May, giving a succession of cobs until late summer. Alternatively, an earlier sowing can be made under glass in April and the young plants transplanted in June as soon as their roots bind the soil together. Unusually among vegetables, sweet corn is wind pollinated, so planting in blocks, rather than in rows, will increase the chances of successful pollination and lead to well-filled cobs.
Sweet corn are normally ready to harvest when the tassels begin to dry up and turn brown in late summer. When a milky liquid is exuded from kernels punctured by a fingernail, the sweet corn is at peak flavour and texture.
Different cultivar types
Sweet corn is usually sweet but quickly turns starchy after picking. Older cultivars are still offered, but most people prefer newly bred selections that have more tender kernels.
Cultivars described as sugar-enhanced have the same amount of sugar as normal sweet corn, but they take longer to turn starchy after picking and therefore hold their flavour for longer, and they have a more tender skin.
Supersweet sweet corn, with a natural gene for high sugar levels, is preferred by many, but the seeds can be tricky to germinate, as they are prone to rotting when sown in cold soil.
Tendersweet or xtra tender sweet corn are even sweeter than supersweet cobs and have such tender skins they can be eaten, uncooked, fresh from the plant.
Guy Barter