Alliums (Ornamental onions)

The genus Allium has many species and cultivars. We offer a number of large-flowered Alliums and a number of Alliums suitable for naturalising.

The large-flowered Alliums (Dutch name: sierui or garlic) prefer a sunny spot, but also thrive in partial shade. Ornamental onions flower when most perennials have only green leaves. They are therefore great for combining with perennials. Plant them in large numbers, give them some extra fertiliser every spring and enjoy a blooming border in May and June! When planting, pay attention to the height of the ornamental onions and perennials: During flowering, the ornamental onions should stick out above the perennials! Flowering Alliums may disappear under the leaves of the perennials later in the season.

How do you propagate Allium (Ornamental Onion)?

Propagating ornamental onions can be done generatively by seed or vegetatively by daughter bulbs. Sowing out makes sense only with pure bulb varieties. Until the seed has developed into a bulb that can flower, several years may pass.

Is Allium (ornamental onion) perennial?

The majority of Allium are perennial bulbs. When digging up the larger varieties, 2 bulbs together form one plant. One bulb is sold and the other replanted. After flowering, they can remain for years. The leaves draw nutrition from sunlight and strengthen the bulb, which blooms again the following year. Let the leaves turn yellow before removing them; this energises the bulbs. They can also spread by seed. Sowing and raising them is easy. The species A. moly, A. oreophilum, A. sphaerocephalon, A. stipitatum, A. atropurpureum, A. caeruleum, A. cernuum, A. flavum, A. puchellum, A. triquetrum, A. ursinum and A. zebdanense are suitable for naturalising.

Where do I plant Allium (ornamental onion)?

Most ornamental onions do well in the sun, in well-drained soil. Plant the tallest varieties in a protected spot so that the stems are not too much of a nuisance when it is windy. In gardens with more shade, you can plant Allium moly.