How to grow... Sweetcorn

Rocket Growing Guides


Nothing compares to your own home grown, freshly picked corn-on-the-cob. One mouthful and you’ll see just how different it tastes to any sweetcorn you buy in the shops – so much sweeter and juicier. And best of all, they are virtually pest free so you shouldn’t have any trouble growing them.

It is best to plant them in a grid rather than a single row, as this will allow for better pollination (sweetcorn relies on wind pollination) and thus well-formed cobs.

  • Planting Tips
  • Common problems
  • Chef's Corner

A sunny site

Choose well drained soil in a sunny, sheltered site for the best results.


Raised beds or a traditional veg plot is best

Sweetcorn plants need a little space and are best grown in raised beds or an allotment. Because they are so tall they are not well suited to growing in pots, however you can grow baby sweetcorn (Minipop) in pots or a growbag.


How far apart?

Allow 40cm between plants (baby corn can be planted 20cm apart)


Plant in grid formation

The key to growing sweetcorn is to plant them in blocks rather than rows – e.g. 3 adjacent rows rather than one long row – this allows for better cross-pollination, which means you’re more likely to get a good crop (if they don’t get pollinated, the kernels won’t swell).


Protect from frost

You need to wait until the last risk of frost before planting your sweet corns outside – until then, grow them in pots under glass. If in doubt, protect with fleece or cloche.


Water regularly

Water well for the first week or so while the sweetcorn plants are getting established. Thereafter they’ll need watering during dry spells.


Keep weeds down

Use a hoe to weed between plants on a regular basis – a couple of times a week should do the trick.


Earth up as plants get taller

Once the plants reach approx 1m tall, it is a good idea to earth them up around the base. Simply bring a little soil around the base of the plant to make a molehill like mound, and firm it down. This will give the plants a little more stability on windy days. (You don’t need to do this for baby sweetcorn)


When to harvest

Harvest sweetcorn towards the end of the summer/beginning of autumn. Once the strands on the ends of the cob start to turn dark brown (almost black) they are ready to pick. You can double check by peeling back the outer husk and piercing a kernel with your thumbnail – if the liquid is milky, it’s ready to be picked. If it’s clear, you need to be a little more patient!

For baby corn, harvest young while the tassels are still pale.


Slug damage to young sweetcorn leaves can look a little different to normal – they don’t like the ribs in the leaves so tend to eat strips between the ribs, somewhat shredding the leaves. Set slug traps, do a dusk slug patrol, and keep your plot as tidy from debris, weeds and other slug-friendly hiding places as possible.


These are a surprising pest sometimes found in sweetcorn cobs, as they like to bury under the leaves on the husks. To entice them away from your crops, a few rolled up newspapers, dampened, and left lying on the soil can work. Empty out the newspaper roll from time to time at the other end of the garden!

Brown/yellow leaves

This kind of discolouration on leaves is usually due to a lack of water and nutrients. Water regularly, keeping the soil nice and moist, and apply a fortnightly liquid feed.

Storage Tips

Sweetcorn doesn’t store very well – it’s best to pick what you want to eat just before you cook it. They will last in the fridge for a few days, but it changes the texture and flavour for the worse…

Ways to cook

Surely the best way of serving sweetcorn is barbecued straight away when you pick them, with plenty of butter, and a pinch of sea salt and cracked black pepper. It’s one of the highlights of late summer!