Allium fistulosum. Bunching onion grows as a clump which is joined at the roots, and is non-bulbing. They are vigorous, evergreen and hardy, can be planted in any season. Also known as scallions or spring onions. Grows 1-2' tall by 1' wide. Blooms late summer to fall. Full sun. Plant in loose, loamy soil. Zones 6-9.