Onions

It really depends on your weather and what is yet to come. Older seedlings can handle cold weather, younger ones don't always do as well. If the forecast is still unpleasant and cold, move the seedlings into larger pots or some sort of planter where they can keep rooting until it's a better time to plant out. Left in small units, the roots 'girdle' - keep going round and round inside the pot and are sometimes difficult to straighten and/or separate.