A few weeks ago I sorted through the remains of last years onions, mainly
the variety 'Stutgarter' which had been stored in string bags over Winter.
There were a few small ones that were sprouting and too soft to use in the
kitchen, but rather than putting them on the compost heap I planted them,
thinking they would either fatten up or run to seed in which case I'd
harvest the green shoots for stir fries. However, today I noticed that each
onion has become three onions! They are like spring onions! Is this normal
behaviour for Stutgarter onions or have some shallots somehow got mixed up
with them?

David.