Maize

Maize is a tall annual grass reaching 150–180 cm, producing large leafy stalks topped with male tassels and lateral female ears that ripen into cobs of yellow, white, or multi-coloured kernels. It demands full sun, warmth, rich soil, and consistent moisture to set well-filled ears. Wind pollination makes block planting essential for good cob fill. In Nordic gardens, short-season varieties selected for cold-soil germination and quick maturity are the most reliable choice.

Growing

Pre-start seeds indoors 3 weeks before outdoor planting, sowing 3 cm deep in individual pots once indoor temperatures are reliably warm. Transplant outdoors once nights stay above 10 °C and soil has reached at least 12 °C. Space plants 20–25 cm apart within rows set 70 cm apart, or use double rows with 10–20 cm between paired rows. Plant in a square block of at least four rows to maximise wind pollination. Direct sowing is possible once soil hits 12 °C — sow 3–5 cm deep. Choose early-maturing varieties (70–90 days) for reliable harvest in short Nordic summers.

Care

Water deeply and consistently, especially from tassel emergence through kernel fill; drought at this stage reduces cob size. Apply a balanced nitrogen-rich fertiliser when plants are knee-high and again at tassel emergence. Remove any suckers (tillers) if growing for maximum ear size. Keep the block weed-free when plants are young; once established, their canopy suppresses weeds. Support is rarely needed for compact varieties under 180 cm.

Harvest

Sweet corn is ready when silks have turned brown and dry, the ear feels full and rounded at the tip, and pressing a kernel with a fingernail releases milky juice. Pick immediately at this stage — sugar converts rapidly to starch after harvest, especially in standard (su) types. Twist and pull each ear downward sharply to detach. Popcorn and flour varieties must be left to dry fully on the plant until husks and kernels are hard and the moisture content is low before picking.

In the kitchen

Boil or steam sweet corn cobs for 3–5 minutes and eat straight off the cob with butter. Grill whole or halved cobs over high heat for charred sweetness. Cut kernels from the cob for salads, salsas, fritters, soups, and stews. Flour-type kernels can be stone-ground into polenta, cornmeal, or tortilla flour. Popcorn varieties are best dry-roasted in a hot pan or popped in oil until the kernels open.

Storing

Sweet corn loses sweetness rapidly: consume or process within 24 hours of harvest for best flavour, or refrigerate unhusked ears for up to 2 days. Blanch and freeze kernels cut from the cob for up to 12 months. Dry flour and popcorn types by hanging whole cobs in a well-ventilated spot until fully desiccated, then shell and store kernels in airtight containers in a cool, dark, dry place for up to 2 years.