I have planted far too many alliums. Last autumn I set out a ridiculous number of shallots, lots of garlic, and overwintering onions. In late winter I sowed onions from seed, and I have leeks growing in a container to be transplanted later in the year. I really do not need any more onions, but, of course, I bought some sets anyway. I really am running out of space and the only available spot was in our new and rather shady border, which needed a bit of preparation to loosen the compacted soil before it could be planted up.
I laid these sets out at four inch spacings, a little closer than normal, perhaps, but I am not sure how they will develop in this position, and they are a bit late going in due to the recent cold. Once in growth, a cold spell may encourage them to bolt so although onion sets are often available early in the year it is better to wait until at least the latter part of March to put them in the ground. This year it had to wait until mid April. Of course, they can be started under cover in cell trays or small pots, and in colder parts of the country that may well be a good idea. I would not normally have to wait so long here in the South, but it has been a pretty harsh start to the season.