How to grow sweet corn in a small garden

The shape of the planting matters more than the size of it

Corn gets written off as a crop for people with a paddock, and I get why, because every picture of it is a field. The thing that actually decides whether you get a cob worth eating isn't how much room you've got, it's whether the pollen from the tassel on top lands on the silks below, and corn does that job with the wind rather than with bees, so a short fat block of plants works and a long thin row does not.

That's good news if your garden is small, because a block of 16 plants in a square about 1.2 metres each way will pollinate itself perfectly well, and a row of 30 plants down the fence line will give you half empty cobs with gaps in them.

Pick a variety that suits a small patch

We carry sweet corn seed in the garden centre and there are four of them on the rack, Snowgold Bicolour, Early Extra Honey Sweet, Terrific and Kelvedon. They're not on the website, so ring us on (08) 8536 4333 or just come in and have a look at what's on the stand.

If you're tight on room, the earlier maturing types are the ones to go for, because they're generally a bit shorter in the stalk and they clear the bed sooner, which matters when the same square metre has to do something else afterwards.

Plant in a block, and plant it close

Sow the seed about 25mm deep and about 30cm apart in every direction, and make the planting at least 4 plants by 4 plants. If you only have room for 9 plants in a 3 by 3 square, that still works. What doesn't work is 12 plants in a single line, so if that's all the space you've got, run two or three short lines side by side instead of one long one.

Corn wants warm soil to germinate, so wait until the soil has properly warmed up rather than going by the calendar, and if you want a run of cobs rather than all of them at once, sow a second block about three weeks after the first.

Growing it in pots

It'll grow in containers and it does need a decent one, so look for something at least 30cm deep and wide enough to take three or four stalks, because a single plant on its own in a pot has nothing to pollinate with. A group of pots pushed together works better than the same pots spread out around the yard, for the same reason the block beats the row.

Use a proper potting mix rather than soil out of the garden, because garden soil compacts down in a pot and the roots stop getting air.

Feed it, because it's hungry

Corn is a grass and it eats like one. Dig some compost or a pelletised manure through the bed before you plant, and give it something with nitrogen in it again when the plants are about knee high and once more when the tassels start showing at the top. A liquid feed is easy at that point because the plants are too tall to get in amongst by then.

Keep the water up and keep it deep. Corn roots go down a fair way and a quick sprinkle every evening trains them to stay near the surface, which is exactly what you don't want in January. Mulch around the base and you'll water a lot less.

Wind is the other thing

A stalk with a cob on it is top heavy and we get some decent blows through here, so plant where there's a fence or a shed taking the worst of it, or push a stake in beside the outside plants of the block. Mounding a bit of soil up around the base as they grow gives them a surprising amount of extra grip.

Grow something else in the same square

The old Three Sisters planting puts climbing beans and a spreading squash or pumpkin in with the corn, and it's worth doing in a small garden because you get three crops out of one bed. The beans climb the stalks so they need no trellis, and the squash covers the ground and keeps the soil cool. Let the corn get to about 30cm tall before you sow the beans, otherwise the beans win.

Knowing when to pick it

The silks at the top of the cob go brown and dry, and that's your first signal. Peel back a bit of the husk and push a fingernail into a kernel, and if the liquid that comes out is milky it's ready, if it's clear it needs a few more days, and if it's thick and doughy you've left it a bit long.

Pick it in the morning and eat it the same day if you can. The sugars in sweet corn start turning to starch the moment it comes off the plant, which is the real reason home grown corn tastes different to the stuff in a bag.

Shop related products

• Brunnings Premium Potting Mix 36L. For growing corn in pots, where garden soil will pack down hard.
• Neutrog Rapid Raiser 20kg. A pelletised manure to dig through the bed before you sow.
• Neutrog Whoflungdung Mulch 20kg. Goes on around the base to hold the moisture in.
• Go Go Juice 1 Litre. A liquid feed for when the plants are too tall to get in amongst.

Did you know we also stock sweet corn seed in the garden centre, four varieties of it, along with pea straw and seed raising mix. They aren't on the website, so give us a ring on (08) 8536 4333 to check what's on the shelf.

The rest of the seed rack, the fertilisers and the potting mixes are all in the garden centre, and if you're not sure which variety suits your spot, come and ask, because that's a two minute conversation in the shop and an hour of reading otherwise.

More from the garden

• Succession planting, how to keep a summer patch producing
• Companion planting, flowers to grow with your vegetables
• 7 mistakes to avoid in a new vegetable garden

I still plant mine a bit close together every year and then complain about getting in there to pick it, so learn from that one.

Cheers,
Candeece

Follow our Facebook page: Strathalbyn H Hardware