This comprehensive guide provides information on how to grow sweetcorn, including recommended varieties, how to sow and harvest, and tips on feeding, watering, and protecting the plants. It also covers the suitability of different growing environments, the lifecycle of sweetcorn, and how to deal with pests and diseases. The document emphasizes the importance of harvesting sweetcorn as soon as it ripens for optimal taste and sweetness.
I use a rating system to help me decide what to grow and it considers lots of factors, but the main ones are how tasty it is, healthy it is to eat, how expensive it is to buy, how big it's harvest is, when it's harvest period is and whether I can buy it organically and if not how much it's sprayed.
Sweetcorn doesn’t score very highly using this system, because it occupies a lot of ground, during the peak summer growing season, whilst only giving a small harvest, but we still grow it! That’s because it’s one of those crops that tastes so much better harvested and eaten within hours. It also looks great and the kids and grandkids delight in harvesting it.
Freshly picked sweetcorn has a special flavour and sweetness that you cannot buy. The sugars in cobs are only temporary and soon turn to starch, before the kernels eventually become dry corn or maize, so sometimes it’s not about growing the most productive crops!
Assuming you are growing a main crop variety like Incredible and giving it plenty of space, expect 2 cobs per plant and they will come 1-2 weeks apart, so if you want a staggered harvest plant no more than three successions and that might give you a harvest over about 6 weeks. So work out how many cobs you can eat over that 6 week period and divide by 2 for the number of plants.
The challenge is that for good pollination you want a nice block of plants, maybe 3 by 3, ie 9 plants in each succession, which is more than one person will usually eat fresh. So either freeze them or grow for more than one person.
Since most people grow sweetcorn as a treat, rather than a staple, id probably only grow 1m2 of it, unless you have a lot of space, or want to freeze it.
Sweetcorn prefers is well-drained, fertile soil with a pH between 6.0 and 6.8. It is important to ensure that the soil is rich in organic matter and has good drainage, as sweetcorn is susceptible to rot in waterlogged soil. Sweetcorn loves it warm and sunny too, so full sun if possible.
You start sweetcorn in mid to late spring, and plant out ideally after your last frost date, although I’ve seen plenty of crops pull through after a light frost it’s not always the case. I like to plant sweetcorn out when it’s young as it establishes better, that means sowing about 4 weeks before your last frost date for your first succession.
The plants grow extremely rapidly, but when young they are susceptible to high winds, so a sheltered spot or a wind break can be useful if you are only growing a few plants and can afford to make the effort.
Plants develop male flowers at the top from which pollen drops down towards the hairs that develop at the ends of the developing cobs. If successfully fertilised these will soon start to swell.
<aside> 💡 For more details on the model that I use for describing harvest periods (first earlies, second earlies etc) please see the chapter on my growing framework
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