Grow sweet corn

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The sweetest corn of all is one picked from your own garden. Why? Because corn has natural sugar in it and as soon as it’s picked off the plant, the sugar starts turning into starch (which isn’t sweet).

The best way to grow sweet corn is from seed sown straight into the garden. Here’s how…

  1. Find a sunny sheltered spot. Make sure the soil is loose and crumbly. It should be damp but not wet and boggy. Mix in lots of compost and blood & bone.
  2. Plant seeds about 25mm deep, and water gently. Plant in a grid pattern with about 30cm between each plant. Plant two seeds in each place in case one doesn’t germinate. (Pull out the smallest of the two seedlings once they pop up.)
  3. Lay snail bait.
  4. Keep the soil damp (not wet) while you wait for the first leaves to appear in one to two weeks.
  5. Spread mulch, such as compost or straw, around the plants to keep the soil moist. Sprinkle some blood and bone and water thoroughly before you add the mulch.
  6. Fast growing corn needs lots of watering and feeding. It’s easy to feed with liquid fertiliser about once a fortnight. Do this after you have watered. Watering is very important when the cobs start to grow. Soak the soil thoroughly, to ensure water soaks deep down to the roots.
  7. Time to shake your sweet corn! Corn is predominantly wind pollinated. Pollen needs to move from the male 'tassels' (at the top of the plant) to the female 'silks' (on the top of the developing cobs). Give pollination a helping hand by regularly shaking the plants, to release as much pollen as possible.

Its better to plant corn in a grid rather than a single row. This makes it easier for the plants to swap pollen from the tassels at the top of the plant to the silks below. Without enough pollen the cob will be gappy, with grains missing.

When to pick

It's important not to pick too early or too late. In the final growth stage, the silks turn dark brown and dry out as the cob begins to ripen. Also, the cob will start to angle away from the stalk. When pricked, ripe kernels will produce a milky white substance. If the fluid is clear, it’s not ready; if no fluid runs at all, it’s past maturity and likely inedible.


Look for these products, tips and advice at an Go Gardening garden centre near you.



Sweet corn seedlings ready to plant from punnets

Transfer of pollen from tassles to silks will result in succulent corn cobs.