This week... Alliums

Ornamental onions will add an architectural dimension to the garden

- GRAHAM RICE

ALLIUMS are instantly recognized by the smell of their leaves, especially when crushed. Edible types include onions, spring onions, and leeks. Herbs and flavourings include chives and garlic. Ornamental types, often known as ornamental onions, are grown for their attractive heads of tiny flowers.

Ornamental onions either grow from bulbs or make clumps of fleshy roots and may have a particularly pungent smell.

In all alliums, vertical stems are topped with clusters of tiny tubular or star-shaped flowers gathered into heads of anything from 20 or 30 to many hundreds and up to 12in (30cm) across.

Great performers

The leaves may be slender and almost thread-like, or broader and flatter and up to 3ft (90cm) long as in 'Globemaster'. They may die away during flowering or remain green until autumn.

Brent & Becky's, which is the US's top bulb suppliers, tells us: "Ornamental onions perform beautifully, blooming late spring through early summer. They add an architectural dimension to the garden, with many suitable for heirloom gardens and sunny, well-drained meadows. They are also good as dried flowers and pollinator attractors."

Many alliums are good planted between perennials in mixed borders, while perennial alliums are shorter and ideal for the front of a sunny border.

Two kinds of ornamental onions

Some alliums grow from bulbs, in the same way as daffodils, and eventually, make clumps. There are other alliums that grow from slowly spreading roots.

How to buy

THE most economical way to buy most alliums is to buy bulbs from a mail-order bulb supplier, where you will also find the widest choice. Bulbs are also sold in retail nurseries and garden centres.