Sweetcorn (also known by its botanical name of Zea mays) is a delicious vegetable, which is easy to grow. Home-grown sweetcorn tastes amazing! It’s markedly sweeter than supermarket sweetcorn, because the sugar inside the sweetcorn kernels starts to turn to starch once they’ve been harvested. The sooner you eat your sweetcorn after harvesting, the sweeter it will be; home-grown sweetcorn tastes sensational!
This is a tender vegetable. Sweetcorn seed can be sown from the beginning of April to the middle of June, in the UK. Seeds need a temperature of 16-30C (60-86F) for germination; accordingly, you may need to sow your seeds inside a glasshouse, polytunnel, conservatory, heated propagator, or on a very bright and sunny window sill. Wherever you’re growing your Sweetcorn seed, use a good quality, peat-free compost.
If you’re growing Sweetcorn seeds on a window sill, find the brightest location you can offer your seedlings and sow your seeds from the beginning of May onwards. I recommend a later sowing for window sill gardeners, because Sweetcorn plants need a bright location to form strong, healthy growth. Plants that are grown on a window sill for longer are likely to become wearier than those grown in this environment for four weeks or less.
Sweetcorn is a tall and naturally deep rooted plant. If you’re starting your sweetcorn plants off indoors, ensure you use a deep, segmented seed tray or use separate containers, which are deep enough to accommodate your sweetcorn plants’ long roots. Sweetcorn plants don’t appreciate any disturbance around their roots, so it is best to sow one seed per container. Empty toilet rolls work well for growing sweetcorn: just fill the roll with a good quality peat-free compost and sow one seed inside each roll. The filled cardboard rolls, together with their compost and seedlings, can be planted out in their entirety, once planting time arrives in early summer.
Harden your Sweetcorn plants off (every day – for a period of two or three weeks – move your plants outside in the morning and bring them indoors in the evening) before you plant them outside. Sweetcorn plants must only be planted outside once all risk of frost has passed, which is usually around the end of May in the Southern regions of the UK, and between the beginning of June and middle of June, in more Northerly locations.
Plant Sweetcorn in a bright and sunny area. Sweetcorn is wind pollinated; to allow for successful pollination, plant your Sweetcorn plants (or sow your seeds directly) in a block or grid formation. Plant your Sweetcorn, or sow your Sweetcorn seeds 45cm (18″) apart. This may look too far apart when you’re sowing seeds or planting young plants; it may seem tempting to plant closer together, but your plants will soon grow and they’ll honestly need all of this space.
Vegetable breeders have worked hard for a great many years to make Sweetcorn much easier to grow, and better adapted to growing in Great Britain’s cooler summers, with great success.
If you’re growing a more recently bred ‘supersweet’ Sweetcorn cultivar, ensure that you can provide your plants with a rich, fertile soil and you’ll be on hand to water your plants during dry periods, as the supersweet cultivars are a little less resilient and they’re not as vigorous a plant, as the older non-hybrid Sweetcorn cultivars. If you cannot provide optimum conditions, you’ll have more success with an older non-hybrid Sweetcorn cultivar.
It’s important to note that the two types – supersweet Sweetcorn cultivars and older Sweetcorn cultivars are best grown on separate sites, as the plants are easily cross pollinated, which can lead to tougher, chewier sweetcorn being produced.
Badgers absolutely love sweetcorn! Badgers can come along one evening, just before Sweetcorn fully ripens on the plant and destroy a healthy crop grown in a garden, or at an allotment, leaving the site looking like it has been targeted by vandals, with half eaten discarded cobs left on the ground and everything in that area out of place.
Slugs and snails, mice, and birds can also be pests of Sweetcorn; between them these creatures may to tempted to eat Sweetcorn at every stage, from the seed that’s freshly sown, to every part of the fully grown Sweetcorn plant and its delicious cobs.
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Articles that mention Sweetcorn:
- Jun. 2019 – Medwyn Williams wins his 12th Gold Medal, at the RHS Chelsea Flower Show 2019
- Apr. 2019 – Lovely things to do in your garden, or at your allotment, from mid-April to mid-May
- Nov. 2017 – Access Garden Products Classic Growhouses
- Sep. 2017 – Asparagus
- Jul. 2017 – Juliet Sargeant and the RHS Kitchen Garden
- Jan. 2017 – Sweetcorn ‘Bodacious’
- Nov. 2016 – Deep Rootrainers and the Rootrainers Racking Station
- Dec. 2015 – Suttons Seeds Bodacious Sweetcorn Shoots!
- Nov. 2014 – Garden Advice for Mid-May to Mid-June
- Nov. 2014 – Gardening Advice for Mid-April to Mid-May
- Nov. 2014 – Gardening Advice for Mid-May to Mid-June
- Nov. 2014 – Garden Advice for Mid-April to Mid-May