Horticulture Magazine

Sweet Corn

corn plantation


Official Plant NameZea mays
Common Name(s)Corn
Plant TypeVegetable / Annual
Native AreaAmericas
Hardiness RatingH2
ToxicityEdible kernels
FoliageAnnual blade-shaped leaves
When To Sow IndoorsApril, May
Plant OutJune, July
Harvesting MonthsJuly, August, September, October

Full Sun

Sheltered (requires protection in colder areas)


1 – 2M

0.1 – 0.5M

Bloom Time


Most fertile soils

Moist yet free draining


Nowadays the most common ways to eat sweet corn involve scooping spoonfuls of kernels out of a tin and into a sauce, a salad, or some other dish.

Corn on the cob makes an appearance at barbecues and grills, sure, but gone are the days where people’s main experience of corn would be in this format.

And you know what? We think this is a little bit tragic. There’s something special about food you eat with your hands, and a corn on the cob is the quintessential example.

In this guide we’ll give you the lowdown on what you need to do to grow your own corn. So if you’re looking for a steady supply of home-grown corn on the cobs, read on!

man harvesting corn on the cobs
Corn on the cobs from the comfort of your own garden

What is sweet corn?

Sweet corn is a yellow vegetable, and the word refers both to the cob, and the kernels that grow on it. Although we’re guessing you don’t need an introduction that basic!

Dig a little below the surface level answer and the properties of sweet corn are actually quite interesting. This crop is a variety of the grain maize, known for its particularly high sugar content arising from a natural genetic mutation that encourages the production of more sugar.

This means that humans have evolved to pick corn before it reaches full maturity and eat it as a vegetable, rather than letting it mature into a grain.

Why grow sweet corn?

Whenever we’re asked why to grow a certain fruit or vegetable, the first reason we usually give is “because it’s delicious!” And with sweet corn, this answer is very much applicable.

A grilled corn on the cob with a crack of salt and a coating of melted butter is amongst the most satisfying and enjoyable dishes we can think of. Using a corn you’ve grown yourself, with its especially sweet and delicious flavour, takes the dish to another level.

toasted corn on the cob with butter
The best dishes are often the most simple

There are other reasons, too. Corn’s tall and distinctive aesthetic makes an attractive addition to your garden, and the crop offers flexibility in the number of varieties available.

Taking time to choose the right variety lets you grow corn whose flavour profile best aligns with your palette.

How to grow sweet corn

In the sections below we provide step by step information on how to grow your own bumper crop of sweet corn.

While you may be used to seeing fields upon fields of corn growing, it’s also possible to grow a few plants in your garden – so don’t be put off if you don’t have much space!

Sowing corn

For best results, sow your sweet corn seeds into pots in a greenhouse or a cold frame or similar.

Doing so gives you a head start when compared to sowing directly outdoors, as you can shelter the seedlings from harsher temperatures.

If you decide to sow this way you can begin growing your corn around a month before the last frost!

Pop some soil into small containers, then push seeds an inch down below the surface. Corn is not fussy with soil types: any potting compost should do the trick.

Sow two seeds beside each other, then remove the weaker seedling before the next step.

Planting out corn

Once your corns are about six inches high, they’re strong enough to make the transition outdoors.

Ideally you’d harden them off before planting them out, and doing this is easy. Just leave the plants outside for short periods of time in the week before you plan to plant them, with the periods gradually getting longer.

If you’ve got a cold frame this is the perfect space for hardening off corn (providing the lid is high enough to accommodate your six inchers!)

young crops hardening in a cold frame
Cold frames are great for hardening off young crops

While many crops grow best in rows, we recommend planting out corn in blocks as this gives it the best chance at pollinating.

Corn is pollinated by wind, and placement in a block increases the spores’ chance to spread. If your crops aren’t able to pollinate enough they’ll still grow, but you’ll have fewer kernels.

Look to plant your corns about 18 inches from each other in all directions. To plant, remove from the pot, tussle the roots to loosen everything up, then pop into individual holes.

Once a corn is in its hole, firm up the soil around the base of each plant to keep it secure.

Where to grow your plant

Before planting your corn, find a good spot and enrich the soil with compost or other organic matter.

Dig this through the soil well to maximise the nutrients available to the corn, potentially even adding a fertiliser that’s high in potassium.

Corn grows best in a spot that gets plenty of sunshine, and while they require wind to assist with pollination, try to choose somewhere that’s sheltered from the worst of the elements.

You want your corns exposed to a gentle and regular breeze rather than strong winds that can build up speed in open spots.

If you’re growing squash you can also grow your sweet corn amongst it, as the two plants complement each other well by taking different things from the soil.

Native American farmers were renowned for growing ‘three sisters’, which is corn, squash, and beans grown in a symbiotic arrangement. If you’re feeling particularly adventurous you could try out this method!


As well as preparing the soil before planting your corn, we advise on mulching the soil at the base of your plant with garden compost while growing.

This will help to retain moisture and to reduce weed coverage.


In dry weather make sure to water your corn plants frequently.

This is especially important when the plants are flowering, as this is when they’re at their thirstiest.


Corn is just as prone to weeds as any other plant, although hopefully mulching should help to reduce their number. If you use a hoe to help with your weeding, go carefully.

Corn has shallow roots and hoeing too aggressively can damage the crop along with the weeds.


Corn is ready for harvesting when its tassels turn brown and darken. This usually occurs a few weeks after they initially appear.

The physical act of harvesting is quite easy: either pull or twist the corn away from the stem. If pulling isn’t working, a gentle twist should help.

To test whether your corn is ready, there’s a test you can do before removing the cob from the plant.

Simply peel back part of the sheath and press a fingernail into a kernel. If the liquid inside is creamy in colour, the corn is ready to go. If the liquid is watery it’s not quite ready yet, and if there’s no liquid you’ve left it too late!

Once harvested, remove the sheaths from your cobs and cook as soon as possible.

Many gardeners swear that the best taste is achieved by cooking almost instantly after harvest.

If you’re not planning to eat it immediately however, we recommend refrigerating before removing the sheaths.

Troubleshooting common problems

Sadly, corn is very appealing to all manner of garden pests including mice, birds, and creepy crawlies. Here’s how to deal with some of these pesky visitors.


You’ve seen the cartoons: mice are suckers for a bit of food placed temptingly in a mousetrap.

Cheese, bits of vegetable, or even peanut butter can make good bait.

Just be careful to not accidentally trap birds: placing your traps under a cover is a good way to prevent this.


While you don’t want to catch birds in a mousetrap, you do want to deter them from eating your corns.

The best way to stop these flying critters from ravaging your crop is to cover it with a material that lets in air and sunlight but keeps out beaks.

Fleece or mesh are good bets.

Slugs and snails

Whatever you’re growing, it’s likely you’ll have to contend with these menaces.

There are many ways to deter them including sacrificial crops designed to distract them, beer traps designed to drown them, or pellets designed to poison them.

The right solution for your garden will depend on the level of humaneness you require.

Sweet, sweet corn

We love sweet corn.

It’s versatile and delicious, and as we said earlier, there’s something deeply satisfying about the tactile aspects of the eating experience, from peeling the sheaths away right through to holding the cob in your hands to eat it.

While it’s less and less common to eat corn on the cob these days, especially fresh from being harvested, doing so is easily within your reach.

We hope that this guide has been helpful in showing you just how easy corn is to grow, and we hope that you’ll soon be enjoying the fruits of your industry.

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