How to grow sweetcorn

Sweetcorn can thrive in the home patch if it’s in good company. Follow a few simple tips and say cheers to big ears.

By Mat Pember
Sweetcorn can thrive in the home patch if it's in good company, writes Mat Pember. Follow a few simple tips and say cheers to big ears.
Whole societies are fuelled by corn. Half the world would fall apart if corn ceased to exist. More than just a crop, it's a critical food commodity, and in the home garden nothing speaks more of summer than those lanky stems swaying in the sun.
Corn plants rely on each other to pollinate, so to grow corn in the home patch you need a minimum number of plants to ensure a decent return. Any fewer than 12 to 16 makes it a tricky proposition; some may be fully kernelled, but others will look like your grandfather's mouth without his dentures.
When growing sweetcorn at home, you need to allocate at least a square metre of space for your plants because they'll need 30 to 40 centimetres between them to reach healthy maturity. Sweetcorn is particularly hungry for nitrogen, so prepare the space with plenty of compost and good manure. We use slow-release chook poo pellets, which fuel the plants over time.
When planting from seed, make the holes two centimetres deep and 30 to 40 centimetres apart in a grid formation. Sweetcorn seeds have a hard coating, so soak them overnight in water before you plant them. Any that float to the surface during soaking won't be viable, so discard them.
Sow two seeds in each hole, then water them thoroughly. Given that it's summer, the patch will need watering daily to ensure the soil holds enough moisture to germinate the seeds - which should take about seven days - and then sustain the young seedlings. Once the seedlings begin to grow you may need to cull one if both seeds in a hole have germinated, allowing the healthiest to thrive.
If you're planting seedlings, do so during the morning of a relatively cool day if possible. The rule of thumb for planting is that the worse the weather for the beach, the better it is for planting. As always, water the seedlings 15 minutes before planting to reduce potential transplant shock.
Once the seedlings are up and running (about two weeks after germination), it's time to mulch the patch. It's summer, it's hot and soil can become hydrophobic if left to bake exposed in the sun.
We use heat-treated mulching pellets, which are easy to apply around young plants and expand when watered. Because they're heat-treated, they contain no weed seeds, and the pellets are easy to handle and dust free. Mulch to a thickness of two to three centimetres.
The soil type determines the frequency of watering over the next couple of months. Sandy soils and potting mixes will need watering every day first thing in the morning, while a richer loamy soil, which better retains water, will need water every second day. If you have holidays planned, install a simple drip system to ensure you come back to something green.
After a couple of months, cobs will begin to form, and subsequently their kernels. More watering is needed and an application of liquid potash will aid their development. Since the plants pollinate each other, the more plants you have, the greater the likelihood of success, and you can assist with pollination by gently shaking the plants to transfer the good stuff around. This is a good task for the kids; set the shake level to gentle and set them to work. Another way to hand-pollinate is to use the tassels of the corn (on top of the plant) to feather-dust the silks protruding from the cobs. This transfers pollen to where it's needed to fertilise each silk, which then produces a kernel.
When the silks begin to brown the corn is almost ready to pick. Check by carefully pulling aside the husks and, if you're satisfied with the offering, pull down sharply and twist off the cobs. One plant will produce two to four cobs, if you're lucky, so expect a good supply of barbecuing produce for about a month.
Tip of the month: picking seed heads
Lettuce and other leafy greens can develop seed heads for a number of reasons and, other than for the purpose of collecting and saving seeds, none are particularly welcome in the vegetable patch. So why do plants develop seed heads in the first place, and what can we do to stop them? Read on.
Stress factor
Just like us, plants get stressed. While we destress by drinking too much and going paint-balling, plants will shoot out a seed head. It's their way of saying, "It's been fun, but I'm outta here."
Why and how?
A plant's seed can be caused by transplant shock, lack of picking or the natural conclusion of its life cycle. We can't do much when a plant's time is up, but premature seeding can be easily rectified. Using sharp nails or sharper scissors, pinch out the seed heads as far down the stem as possible to refocus the plant's energy into growing food. Simple.