Secrets of Growing Sweet Corn Successfully

Sweet Corn
Beautiful Sweet Corn – ready for picking.

Sweet corn, as opposed to big white mealies or maize, is a great crop to grow in your vegetable garden. While they do need to be reasonably widely spaced, even a couple of short rows at the back of your plot can produce gorgeously sweet corn cobs – better than anything you could ever buy in your supermarket or greengrocer’s shop.

Whichever cultivar you decide to plant, remember that it is essentially a warm-season crop that will thrive in the summer months, particularly in regions that are reasonably dry. Because it grows tall, it doesn’t do well if constantly battered by wind.

Like the squashes, marrows and pumpkins, sweet corn is a dioecious plant, meaning the male flower (in this case a tassel of sorts) is produced at the top of the plant with the female flowers (silks) growing lower down on the stalk. It is pollinated by the wind, and if the weather is consistently wet, pollination may be incomplete and you will produce odd-looking corn cobs with gaps in them – rather like a toothless old man!

As with all other vegetables, the first step when growing sweet corn is to prepare your soil. You need clean, well-drained soil with plenty of nutrients. So dig in compost and manure, and treat with a compound fertiliser containing nitrogen, phosphorous and potassium (N, P, K). Also be sure to aerate the soil to a good depth. This helps improve the fertility of the soil and allows water to soak in thoroughly. This is important because sweet corn does best with regular deep watering.

Sweet corn is propagated by seed, directly into the soil, about 40 mm to 50 mm below the surface. The seeds are in fact dry kernels so they are easy to space out (unlike very find seeds). Plant more than you need, perhaps a little more closely than recommended on the packaging, because then you can selectively remove any seedlings that are not growing strongly. Ideally plant out a block of short rows, running north to south to minimize the impact of shade on the growing plants.

As the seedlings emerge, you will invariably find that weeds do too. Remove these carefully, by hand, as soon as possible so that the corn can develop a nice healthy root system.

Nitrogen is an essential ingredient for successful sweet corn growing, and it will also increase the yield you get from each plant. Generally it is a good idea to side-dress with a nitrogen-rich fertiliser when the plants are about knee high; and then again about two weeks later. Plants also benefit from mulching.

Common pests include cutworm, which attacks young seedlings, and corn earworm larvae that hatch from the eggs laid by a particular type of moth, and then bore their way into the cobs. So watch out for these and treat early with either an organic or a chemical insecticide. Also keep an eye out for aphids.

Sweet corn should be picked when the kernels are plumb and “milky”. If you’ve never grown corn before you might find it difficult to identify when they are ripe for the picking. If they aren’t quite ready, the kernels won’t be fully formed. Generally they take about three months from sowing to get to this point, and the silks will become dry and withered.

Cook as soon as possible after picking – ideally straight away.

153817f56fcb3c512ee2419b72a60214?s=80&d=mm&r=g Annette (74 Posts)

Annette Welsford has a partial degree in Horticulture and a Post Graduate Certificate in marketing. Having lived in the cold, temperate and hot parts of Australia and the UK, she has gained experience over the years with gardening in a variety of climates. Annette also worked for a fertilizer company where she was responsible for developing, editing and publishing a range of technical manuals on nutrition and fungal diseases for a wide range of horticultural crops including tomatoes. Annette is Managing Director of Commonsense Marketing Pty Ltd, a publishing and marketing company, responsible for the editing, design and worldwide marketing of the How to Grow books, and other products. Commonsense Marketing also provides expert offline and online marketing consulting and design services to a variety of small to medium sized businesses.