Growing Sweetcorn at the Allotment

Growing Sweetcorn at the Allotment

Sweet and juicy, and nothing says summer quite like a corn on the cob. 

Sweetcorn is started from seed (kernels) and is not suitable for growing in containers due to the size and space the sweetcorn plants require. Start the process from late April onwards.

Some growers like to soak their seeds first until they sprout, or you can just plant one or two in a 3 inch-pot, approximately one inch deep in compost. Some growers also like the method of using toilet paper cardboard rolls, however, be mindful that they will dry out quicker and will require more watering. They can be transferred this way, as the cardboard will decompose in the soil when you plant them out.

Wait until the plants are approximately 4-5 inches tall; choosing the strongest and healthiest of your seedlings to plant outside in mid-May. Unlike traditional rows of vegetable plants, the best method for planting out, is to plant them in a grid/square. This helps them pollinate. So, if you have 16, plant them 4 x 4 or as near as, if you have an odd number. Allow 2 ft each way between the plants.

Plant them in manure-rich soil for these nitrogen hungry plants, approximately 5 inches deep and fill the hole with soil. When the sweetcorn has reached approximately 24 inches, draw up some soil around the stem to help strong root growth.

Water well during dry spells and keep weed-free.

The sweetcorn plants will grow tall and will form tassels at the tips. The flowerheads form and pollinate via the wind. When the flowerheads have opened, you can help them along by giving the stems a gentle tap or shake. This will help ensure that the fully formed cobs are filled.

Once the tassels have turned brown, the cobs should have formed and be ready for harvesting. You can feel the cobs for fullness or by peeling back some of the husk and squeezing a kernel. If it seeps milky fluid, it will be ready. Just twist and snap off the cob from the stem.

Keep the cobs in the husks (leaves) until you use them; they freeze well as long as they are fully defrosted before cooking them. They are amazing wrapped in foil and cooked on the BBQ!



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Growing Sweetcorn in Summary

Sowing Sweetcorn

  • Sow indoors late April or directly mid May
  • Sow in blocks, not rows
  • You can soak the seeds until sprouted

Growing Sweetcorn

  • Keep well watered and weed-free
  • Mound up soil around the stems
  • Gently shake the stem when tassel flowerheads have opened to help pollination

Harvesting Sweetcorn

  • Cobs are ready when the tassles have turned brown
  • Squeeze a kernal for milky residue to test
  • Can be frozen