Allium Sphearocephalon

Allium sphaerocephalon

This green to purple summer-flowering ornamental onion looks great planted in combination with Nepeta 'Six Hills Giant', Centranthus ruber and Rosa 'Gertrude Jekyll' ('Ausbord') AGM. Its oval flowerheads stand about 60cm or more tall - insects love them, and they add movement and interest to borders.

Vital statistics

Common name

Round-headed leek

Family

Alliaceae

Height & spread

60 x 90cm (2 x 3 ft).

Form

Bulbous perennial

Soil

Fertile, well-drained soil

Aspect

Full sun

Hardiness

Fully hardy but may be tender when young

 
Round-headed leek is easy to grow. The bulbs should be planted fairly deeply, in a light well-drained soil in a sunny position. Once established the plants are fairly drought-tolerant. It grows well with most plants, especially roses, carrots, beet and chamomile, but it inhibits the growth of legumes. It should not be planted near alfalfa, as each species affects the other negatively. Plants often divide freely at the base.