Alliums

Ornamental Alliums. In my opinion, a plant every garden should have. Five minutes of effort will give you many years of reward.

Alliums are a large collection of bulbous flowering plants including Onions, Shallots, Chives, Leeks and Garlic. Indeed Allium in Latin means Garlic and also in Greek ἀλέω (aleo) means to avoid, presumably due to the smell of garlic.

But it’s the Ornamental Cultivars of Allium, I’d like to write about.

These tall plants are bold and architectural, with large rounded heads of, usually, purple flowers, followed by attractive seed-heads that last through most of Autumn. Cut them back when they look tatty and the whole glorious firework display starts again in late May and June.

Alliums belong to a large and ancient group (emerging about 60 million years ago) of flowering plants called Monocotyledons, or Monocots for short. They include Orchids, Grasses and grass-like flowering plants. In agriculture they include the major grains (rice, wheat & maize), sugar cane, and the bamboos.

Bit of Botany……Monocots usually have well developed, underground storage structures. The plant draws upon these during its winter dormancy and hence the vast majority are Perennial, producing soft, non-woody growth and dying down in the winter. The other part, and the largest, of the flowering plant family (Angiosperms) are called Dicotyledons (Dicots) that include trees and shrubs.

Hence Ornamental Alliums grow from a storage organ, in this case most are from bulbs with a few species (like Allium angulosum) that are rhizomatous, with small bulbs growing from rhizomes.

Ornamental alliums weren’t commonly cultivated until the late 1800’s when botanists introduced species from central and southwest Asia to European botanical gardens. Today there there are over 850 species, and numerous hybrids and cultivars available.

If you were to have just one, then I would go for Allium hollandicum “Purple Sensation’.

It has large 10cm, rounded heads of deep violet, star-shaped flowers, on tall 75cm stems. Perfect for growing in drifts or large clumps in a sunny border. It has been been given an Award of Garden merit (AGM) by the Royal Horticultural Society (RHS).

If you want something larger and more spectacular, then there are several giant Cultivars.

Allium ‘Giganteum’ is perhaps the tallest, growing to 1.5m high with a 12cm spherical flower head. It makes an impressive sight at the back of a border. Again awarded an AGM.

If you’re looking for even larger flower heads, then try Allium ‘Globemaster’ with its 25cm diameter flower head on 90cm stems, again awarded an AGM.

or Allium “Christophii’, the ‘Star of Persia’ with its 25cm flower head of star shaped silvery flowers is a dramatic addition to any border, particularly if planted with ‘Purple Sensation’

If you don’t want purple, then try Allium ‘Beau Regard’

or Allium karataviense ‘Ivory Queen’ with white star shaped flowers on short 20cm stems. Ideal for the front of a border or container.

Or Allium nigrum with a pretty creamy white semi globular flower head on 40cm stems

…so many different Cultivars to choose from.

Planting & Care

• Plant in a sunny position (ideally South facing) but some will tolerate partial shade.

• It’s best not to plant the bulbs in areas of the garden that are regularly cultivated as it is easy to damage the bulbs when digging

• Plant in early Autumn at 4 times the bulb depth, in well drained soil (to prevent the bulb from rotting).

• Alliums are drought tolerant and don’t like to be in wet soil. Once established in a border they won’t need watering. No feeding is required.

• Provide support for the very tall ones, although most are self supporting.

• In winter once the seed heads look tatty, cut back to the ground.

• If planted in a container, then winter protection may be required.

• If clumps of older plants are becoming overcrowded you can lift, divide and replant them after the foliage and flowers have died down.

So Ornamental Alliums. One of the most spectacular plants for little effort. If you haven’t already, then I recommend planting this Autumn.

Most of all, enjoy your Garden