Nothing says sunshine quite like corn on the cob! Growing sweetcorn in the UK is easier than you might think. With enough space, full sun, and the right timing, you can enjoy cobs so fresh and sweet they hardly make it back to the kitchen. The sugars in sweetcorn begin converting to starch shortly after harvest, so eating them right away gives the best flavour.
Sweetcorn is best grown in blocks rather than rows for successful pollination and pairs well with fast-growing shade-tolerant crops like spinach and salad leaves planted in between.
Some popular UK-friendly varieties include:
Read our guide on how to grow sweetcorn in the UK. Sign up on the Allotment Online platform to post your tips and insights!
Before asking when to plant sweetcorn, let's take a look at the ‘how’ of it first. Sweetcorn is best grown from seed, but it isn’t ideal for containers due to its height and spacing needs. Start seeds indoors from late April in trays or pots (about 3 inches wide), planting each kernel 1 inch deep in compost.
Maintain a warm environment (18–21°C) for germination - sunny windowsills or heated propagators work well. Some growers pre-soak seeds until they sprout, while others use cardboard toilet rolls for easy transplanting (just keep them well-watered as they dry quickly).
When seedlings are 4–5 inches tall, harden them off and plant outside in mid-May.
Instead of rows, plant sweetcorn in a block or square formation to aid wind pollination. If you have 16 plants, plant them in a 4x4 grid, spacing each plant 2 feet apart in both directions.
Use nutrient-rich, well-manured soil as sweetcorn loves nitrogen. Dig holes around 5 inches deep, plant the seedling, and backfill with soil. As plants reach about 2 feet tall, mound extra soil around the base to support root growth.
Sweetcorn plants are wind-pollinated. Tassels (the male flowers) release pollen that falls onto the silk (the female part) below. In smaller patches, help nature along by gently shaking the stems or using your hands to dust the pollen over the silks, ideally within 10 days of silk emergence.
When growing sweetcorn in the UK, water regularly during dry spells, and mulch with compost to retain moisture and suppress weeds. Taller plants may need staking or canes to prevent wind damage, and extra soil around the base provides anchorage.
Once the cobs begin forming, they can attract all sorts of visitors like badgers, squirrels, mice, slugs, and snails among them. Protect your harvest by covering cobs with netting.
The next question you might have is when to pick sweetcorn?
You’ll know your cobs are ready when the tassels turn brown and the cob feels full. Peel back the husk slightly and press a kernel - if a milky liquid appears, it’s time to pick.
To harvest, simply twist the cob downward and snap it off the stem. Keep the husks on if storing. Sweetcorn freezes well, but be sure to defrost fully before cooking. For the best flavour? Wrap in foil and cook on the BBQ!
Whether you’re a green-fingered expert or just starting your growing journey, Allotment Online is here to help. Our step-by-step crop guides and friendly community support you from seed to harvest.
Visit our Grow Your Own section for inspiration and growing tips, and don’t forget to share your growing wins with us!
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