Best to buy crocosmias in good sized pots, not corms, etc. they really are a very i vigorous plants, even the smallest of varieties. You are sure to see them in garden centres now or in B & Q, etc. crocosmias are weeds in Cornwall...we are constantly digging them up. It's wild cousin montbretia can be seen in the hedgerows, fields etc etc. I think crocosmias are damaged by frost if it's severe in colder parts of the country