This grower is sure of this plant identification.
Allium sphaerocephalon (Round-headed leek). This is a perennial species with linear mid-green basal leaves, and the reddish purple flowers are held tightly in small egg-shaped umbels in early summer.
You should grow in fertile well-drained soil with full sun. The bulbs should be planted in the autumn and will prefer to be grown in hot dry areas in a sandy loam-based potting compost.
Borders, ornamental, often used in 'prairie-style' plantings.
Italics = data drawn from parent genus or speciesView Full Plant Finder Record