Sowing onions
Many gardeners grow their onions from sets (small bulbs), forgetting that seed is capable of producing a much larger crop of onions come the summer. Onion seeds are not long lived so, rather than settling for last year’s leftovers, always buy new. Keen growers with their eyes on the show bench will traditionally sow their onion seed on Boxing Day, but I think that January or February is soon enough. It allows plenty of growing time for them to make up ground on sets that are planted out in March/April.
Germinate the seeds in a temperature of between 16°C and 21°C. The warmer the temperature, the quicker germination – anything between one and two weeks. When they are large enough to handle, transplant the seedlings into individual cells and keep them in a bright, frost-free place (16-18°C) until April when they can be planted out on the veg plot.