Preparing the site
Choose a sunny site that's protected from strong winds. Sweet corn is a hungry crop so it's important to enrich your soil before planting. Add a plenty of aged manure and a handful of blood and bone per square metre and fork it in well. Sweet corn will do well in a bed that's previously grown healthy peas or beans. In the right conditions, each plant will usually produce two ears of corn.
Planting
Plant seedlings or seeds 30cm apart and plant in blocks (4 x 4) rather than a single long row (1 x 16). Planting in blocks assists pollination which is essential for the development of kernels. Plant early and late varieties in separate blocks for a longer season. Water seeds well after planting then sparingly until germination occurs as the seeds can rot easily.
When the stalks are about 20cm high, mound the soil up against the stalks. This process, called hilling, encourages more roots to grow which will help stabilise the plant during windy conditions. You can also achieve the same result by planting the seeds in a furrow and backfilling as the plants grow.
Watering and fertilising
Once the plants are well underway it's important to ensure an adequate moisture level, especially since the plants will be at their peak of production over the hot months. Drip irrigate if possible and mulch well to retain moisture.
As soon as the tassel appears at the top of the plant, give the soil a boost with a granular fertiliser that's high in nitrogen.
Pollination
Pollination is key to a successful sweet corn crop. The tassel grows from the very top of the plant and sheds pollen onto the silks of the developing cobs which grow lower down. Each individual silk is attached to one kernel of corn, and in order for that kernel to develop it must be pollinated. Insufficient pollination results in ears of corn with lots of missing kernels.
Planting sweet corn in one long single row can result in most of the pollen being blown away, which is why gardeners plant corn in blocks instead. Some gardeners even hand pollinate their sweet corn by cutting off a pollen-laden tassel each day and gently brushing over the silks with it.
Sweet corn is ready to pick 2-3 weeks after pollination and it's important to keep up the water during this time.
Harvesting
Test for ripeness as soon as the silk on the cob has turned dark brown and the cob is angled away from the stem. Peel back the husk and pierce one of the kernels with your fingernail. If it oozes a milky substance it's perfect for harvesting. Immature kernels will be watery. Hold the stalk and pull the cob down firmly to break it off. Eat immediately after picking for maximum sweetness and refrigerate any excess, leaving the husk intact. How to store vegetables
Look out for these varieties
Terrific - an early maturing variety with large cobs.
Bicolour Snowgold - large cobs with yellow and white kernels.
Minipop - a mini variety which should be picked before the grains begin to swell. Expect five to six ears per plant.
Try some of our other veggie-growing tips
How to grow microgreens
Plant some easy-peasy potatoes
How to grow blueberries
Start an indoor edible garden
