It’s one of life’s great pleasures. When you sink your teeth into the first cob for the season, you know that Summer has well and truly arrived.
If you want some this Summer, there is still time to get it in the ground. I sow four separate plantings of sweet corn in a season to get a continuous supply for months. Mid September is when I sow the first seeds, followed by three more sowing a month apart. I have been growing it successfully this way for six years in my current veggie patch and this is how I do it.
Sweet corn requires rich soil with plenty of nitrogen and moisture. Even good garden soils may need some fertiliser to produce a top-quality crop. A week before sowing or planting add, aged chicken manure and/or compost, mixed well into the soil, will do the trick. Growing corn in an area that had healthy beans or peas the previous year is a good thing to do because these legumes contribute more nitrogen to the soil. Cornstalks growing with ample moisture and in well-prepared, fertile soil can be expected to produce two ears per stalk and reach 2 meters in height. If needed, adjust the pH to a level of 6.5 by adding lime.
Place two or three seeds into a 3-4 cm deep hole. Each hole spaced 30-35 cm apart in rows that have a spacing of 35-40 cm. Because corn is wind-pollinated, plant it in blocks rather than in a long single row. By doing this you will encourage better pollination because regardless of the breeze direction, the silks are more likely to become covered in pollen. You can buy plants if you prefer but make sure they are young, growing lushly and not stressed in the punnet. I prefer to sow seeds directly into the soil to avoid transplant shock. A tip for first time corn growers, don’t mix varieties. Cross pollination will give you poor tasting, starchy corn cobs. I have learnt this the hard way and it’s very disappointing to sink your teeth into tasteless corn after months of anticipation.
Lack of water is one of the main reasons for a poor sweet corn harvest. Water seed well after sowing because good soil moisture is critical for the germination. If you decide to transplant from punnets or pots, soak them thoroughly. Consistent soil moisture is important for steady growth, so I water every day using drippers. As plants grow and weather becomes warmer, watering frequency increases.
With good soil preparation, most of the nutrition should already be in place for the crop. When the young plants are 20 cm high I give them a light dose of liquid fertilizer and as the crop grows, followed at three weekly intervals with a full strength dose. If it rains heavily, consider giving an extra dose to replace any nitrogen that has washed away.
Snails and slugs will make short work of your seedlings if you are not vigilant. Another problem pest is caterpillars that make their way into the top of the developing corn cobs and wreak havoc. I learnt a trick of gently squeezing the tops of the corn cobs before the silks die off to squash the caterpillars while they are young. I do this a couple of times until the silks have fully died off. Aphid is another pest to contend with and can be controlled by hosing them off or using an insecticide.
When the silks have fully died off, I begin to get impatient and pull back the husk to check if the corn kernels are fully developed. If not, I just recover the corn and wait a couple of days. Depending on the variety, harvesting should be between 80-100 days from sowing.
So that’s it, with a bit of planning and preparation, a good harvest is guaranteed. The very best sweet corn you can ever hope to eat is picked from your own garden, thrown into a pot of boiling water soon after it has been picked, and then served hot, lavished generously with a coating of butter and sprinkled with just a dash of salt.
So get on with it, go and plant your sweet corn!