Raising onions from sets may not produce as big a crop as raising them from seeds, but you will have onions in a much shorter time. You can buy sets of certified bulb onions and the heat-treated ones are resistant to bolting.

Once the soil is more workable, sets should be planted around 10-15cm (4-6in) apart in rows the same distance. Don't just push them into the soil, plant them with a trowel and trim off the dry skin at the tip of the set to stop birds pulling them out of the ground.

Onions need good soil and free drainage, but sets require neither the fine tilth nor high humus content which is necessary for seed-sown onions. Soil should be dug in early winter and compost added. Liming may be necessary if you have acid soil. The aim is to grow them dry and hard.