BBC - Gardening - Gardening Guides - Techniques (2024)

About sweetcorn

Sweetcorn is wind pollinated and best planted in large blocks, where the male flowers at the top of the plant have more opportunity to shed their pollen on the female tassels (where the cobs will form) below. Each plant will produce one or two cobs, so work out how many cobs you're likely to need (you can freeze them) and provide enough space to achieve this.

What to do

Soil preparation

• Sweetcorn likes free-draining, moisture retentive soil. If you can, prepare the bed the previous autumn before planting, adding plenty of well-rotted manure to the soil.
• Don't worry if you never had time, beds can still be made in the spring. First remove weeds and dig over the site with a spade, removing any particularly large stones.
• Level roughly and then work over the area with a rake to leave a fine finish.

Seeds or plants?

• Ready-grown plants will establish quickly and provide cobs earlier than sowing seed directly into the soil.

Sowing into pots

• In April, fill a 7.5cm pot with compost, make a 2.5cm deep hole in the top with dibber (a pencil will do if you don't have one) and drop two seeds in.
• Cover, water and put on a windowsill to germinate. When seedlings are about 2cm tall discard the weakest one and put plants in a shady place outdoors to toughen up before planting out.

Planting out

• To ensure your crop gets off to a flying start, spread some general fertiliser granules over the planting area and gently rake in to the surface.
• If you can, try to do this two or three weeks before planting or sowing.
• Ready-grown plants can go into the soil from May. Using a trowel, set sweetcorn plants 35cm apart with 60cm between rows to form a block.
• There are no rules about how large the block has to be, this will be determined by how many plants you decide to grow.

Sowing into the soil

• Alternatively, if you forgot to grow plants earlier, you can still grow corn by planting seeds directly into the soil in late spring and early summer.
• Use a dibber to make 2.5cm holes and sow two seeds every 35cm with 60cm between rows. Cover and water.
• Remove the weakest of each pair of seedlings when they're about 2cm tall.
• In cooler climates it's worth protecting the emerging seedlings with fleece, held down with stones.

Aftercare

• Keep plants well watered and the soil weed free.
• Use a Dutch hoe to slice off annual weeds, taking care not to sever the surface growing roots of the sweetcorn.
• To protect these and to give plants more stability, pile soil up around the stems with a draw hoe.

Harvesting

• Corn is ready when the silky tassels at the end of the cobs turn brown, but check by carefully peeling back the leaves and pinching a kernel.
• If the juice is milky, cobs are ready to pick. To do this, simply twist the cob away from the plant.

Watch video

In this video Alys Fowler sows sweetcorn.

Five to try

• 'Indian Summer' - cobs of mixed kernels - yellow, red, white and purple
• 'Swift ' - super-sweet variety
• 'Sundance' - creamy yellow kernels
• 'Lark' - very soft yellow kernels
• 'Honey Bantam Bicolor' - yellow and creamy white kernels