Sweetcorn

Essential in the Americas’ diet, especially in Mexico and the Andean region, sweetcorn is delicious even when just boiled with a bit of salt and butter.

Sweetcorn grows easily in long hot summers, but new selections suit better UK’s cool climate. Sow indoors at 18-21°C from mid-April to early May in modules of 2.5cm. To have an extended cropping season, try sowing another two times, 3 weeks apart. Cultivate it earlier in colder regions. To sow outdoors, the best moment is late spring. Sow 2 or 3 seeds per station and leave 45cm between stations.

Soil temperatures should be at least 10°C. Sweetcorn grows better in sunny, but sheltered positions, protected from strong wind. The soil should be fertile, so you can add up to two bucketfuls of organic matter/rotted manure and about 100g per sq m of general purpose fertiliser before planting. 

Check the ripeness when the tassels become brown by peeling a bit of the husk and piercing the kernel with a fingernail. If a watery liquid squirts out, it’s unripe. If it’s creamy, it’s ready. If it’s paste-like, it’s over-mature. To harvest, twist ripe cobs and pull them from the stem. For a better taste, harvest when required to use.

Top Tips

– Don’t grow different cultivars next to each other as cross pollination might lead to poor flavour.

– Sweetcorn is pollinated by the wind, so it’s better to grow it in blocks instead of rows; keeping the blocks 45cm apart.

– Stake the plants individually if they get tall or if the location is exposed.

– Tap the top of the plants when the male flowers open to help pollination of the female flowers below them.

Key timings