Dry and store onions now that their top growth has browned and begun to droop: this is a sign that they've drawn all the energy in their leaves deep down into the roots and are going dormant, ready to store.
Drying your onions hardens the skins and preserves the inner core, keeping it fresh and ready for you to use later in the year. Don't hurry the drying process: you'll need at least a couple of weeks. The idea is to keep the skins baking steadily while keeping the air circulating around them. Ideally you should do this in the sunshine, laid on the surface of the soil, but as we all know in the UK two weeks of solid sunshine is a tall order at this time of year!
A slatted drying rack is ideal for keeping the air circulating around your onions as they dry – and you can move it into the greenhouse or conservatory if it's raining, then back outside when the sun is out. You'll find easy-to-assemble flat pack racks on sale right now in our garden centre here in Chorley. Spread your onions over the top and leave them somewhere warm and sunny to dry off perfectly for winter storage.