Sweetcorn / maize

1. 1

   Sow indoors

   Late April to early May. Use deep modules or 9 cm pots (root-trainers ideal — sweetcorn dislikes root disturbance). One seed per pot, 3 cm deep, 18–22°C. Germination in 7–10 days.

2. 2

   Choose F1 hybrids for the UK

   Standard varieties don't ripen reliably in UK summers. F1 hybrids bred for cooler climates (Lark, Swift, Earlibird, Incredible, Sundance) are essential. Don't mix sweet and supersweet cultivars in the same block — cross-pollination produces starchy cobs.

3. 3

   Prepare a sunny sheltered bed

   Full sun, sheltered from wind, fertile well-drained soil. Fork in compost. The bed should be roughly square for the block planting.

4. 4

   Plant out in a BLOCK

   After the last frost: mid-May in southern England, early June in the north. Plant in a square grid 45 cm apart — minimum 4×4, ideally 5×5 or bigger. Rows of sweetcorn produce poor pollination and patchy cobs; the block ensures wind-carried pollen reaches every silk.

5. 5

   Water deeply at flowering

   Once tassels (male flowers at the top) appear in July, water deeply twice a week. Drought at flowering and silking gives gappy cobs. Mulch heavily.

6. 6

   Earth up if rocking

   Tall stems can be loosened by wind. Draw soil up around the base of each stem when plants are 1 m tall to add stability.

7. 7

   Test for ripeness

   Cobs are ready when the silks turn brown and dry. Test by peeling back the husk slightly and pressing a kernel with a thumbnail — a milky juice means ready; clear juice means not ready; pasty means past-ripe. Each plant produces 1–2 cobs.

8. 8

   Eat the same day

   Sugars convert to starch within hours of picking. Pick, husk, and eat within 1–2 hours for the sweetest cobs. Refrigerate immediately if you can't eat straight away; freezing whole cobs preserves more sugar than fridge storage.

Corn earworm and slugs at seedling stage; birds may take kernels.