Are Alliums Evergreen?

Are Alliums Evergreen? Are alliums Evergreen? Noteworthy Characteristics. Allium fistulosum, commonly called spring onion, Welsh onion, or Japanese bunching onion, is a clumping, slowly-spreading, evergreen perennial onion that is primarily grown as a vegetable for harvest of its tasty onion-flavored leaves. Are alliums deciduous? Some alliums in fact no longer produce seeds at all, but