Sweetcorn is a type of maize. It has a high sugar content which rapidly starts to turn to starch once the corn is picked so you’ll immediately notice a difference in sweetness and flavour between your homegrown sweetcorn and the inferior shop-bought equivalent.
Soil & Growing Position
Sweetcorn needs a fertile soil, free draining but high in humus to help retain moisture and a position in full sun, sheltered from winds.
Dig in autumn as usual adding in manure or compost if it hasn’t been manured from a previous crop and rake in Growmore 2 weeks before planting. Sweetcorn prefers a slightly acidic soil so don’t add in lime.
Sowing from Seed
Sweetcorn should be sown and grown in blocks rather than rows as this helps to ensure that the female flowers are wind pollinated. If you live in the south of the country, you can sow directly outdoors in mid May. Sow 2 seeds together at a 1” depth in 18” squares. If you live in cooler parts of the country, you can sow outdoors under cloches in warmed soil from mid May. Better still, or for an earlier crop, sow under glass in mid April-early May. Sow 2 seeds together at a 1” depth in seed compost in a 3” peat pot. As sweetcorn dislikes having it’s roots disturbed, it’s preferable to use a peat pot as the whole unit will be transplanted. Remove the weaker seedling and harden off by putting in a cold frame or cool porch several days before planting out late May/early June.
Growing On & Young Plants
Once the plants are touching the tops of the cloches, they can be removed. Roots may appear above the surface and these should be covered with soil or a mulch. Sideshoots may develop and these should not be removed. During late June/July you should aid pollination by tapping the tassels, when they are fully developed, at the top of each stem.
Crop Care
Use netting to protect from birds and be careful when hoeing not to disturb the plants. Water well in dry weather and in particular, when the flowers develop. If your site is exposed and/or the plants are tall, you should stake them to provide support. Use a high potash liquid feed, such as Tomorite, once the cobs start to develop.
Harvesting
Harvesting will begin from late July and continue into early October. Pick when ready to cook by twisting the cob off the stem. The silks should have turned brown and then you can test for ripeness by peeling back the sheaf to expose some of the grains. Squeeze a couple of them between your fingers. A ripe corn ready for picking will produce a creamy liquid. A watery liquid means the corn is not ready and a thick, doughy liquid means that it is overripe.
