One in an occasional series of guides on growing popular plants. Other guides include lenten rose, peony, redbud, azalea, elephant ear, lantana, coneflower, savory calamint and rudbeckia.
Alliums, with their clusters of tiny starry blossoms, are close cousins of onions, chives, leeks and garlic. In most popular allium varieties, the form has been perfected in various guises, so that the florets radiate to form a ball that ranges from two to six inches across — or more — depending on the variety. Others have domed umbels. Most garden alliums come in shades of purple, but several are white and some are a bright yellow.
They divide generally into lower growing, small flowered plants and tall alliums with showy floral spheres. They bloom in May and June — rose time in the Mid-Atlantic — when the garden is at its most verdant as it transitions to summer.

Size
The flowers typically reach two to three feet high, though some of the smaller types are just 12 inches tall and the giant spherical ones can have stems four feet tall. Individual plants are rarely more than a few inches across.
[Planting bulbs offers a bit of hope for better things to come]

Use and placement
Smaller alliums, such as the yellow flowering Allium moly and the pink Allium unifolium, look good in drifts that are allowed to recede as the leaves wither in early summer and the bulb goes dormant. The tall, spherical alliums are among the most architectural forms in the garden and should be interspersed among other perennials or ground covers in a way that gives each stem and flower its own space to be admired.

The showy alliums can be cut when ripe, dried and used in arrangements. Some of the less pungent varieties can be cut fresh for the vase, including Allium aflatunense varieties, A. sphaerocephalon and A. moly. Don’t take the foliage; it feeds the bulb for the next year’s growth.

Planting and care
Alliums are not as reliably perennial as daffodils, especially in heavy soil. To give alliums the best chance of persisting and returning each year, give them a sunny location and well drained soil. Those that have spread beyond their bounds can be lifted as the leaves begin to fade, and the bulbs can be separated for planting elsewhere. But in general, plan to augment your stock annually to keep the spring display looking robust.

Varieties
The price of individual allium bulbs varies greatly. Typically, a bulb of an Allium aflatunense variety might sell for 60 cents, while a bulb of an A. giganteum may go for $6. The cost is linked to the ease of propagation and the amount of time it takes the grower to raise a mature bulb. Because you don’t plant alliums singly in a garden, the cost can add up.
For the cost-conscious, I would suggest the popular May flowering Purple Sensation, a variety of A. aflatunense. It grows to 24 inches or more, and the violet-purple blooms are four inches across. Another budget-friendly option is the drumstick allium, A. sphaerocephalon, which rises to 24 inches or so but with groups of small, tightly formed, intensely red-purple blooms that are barely more than an inch across. It blooms from June into July. Or try the one-leafed onion, A. unifolium, a small, umbel flowered bulb growing to 18 inches with two-inch, deep pink blooms. It flowers from mid-May into June. Jeannine is the common variety of Allium moly, another umbelliferous and lower growing allium, but with bright yellow flowers on 10-inch stems in late spring.

Allium “Purple Sensation.” (Colorblends)

Allium karataviense. (Shutterstock)

Allium sphaerocephalon, also known as Drumstick allium. (Colorblends)

Allium “Gladiator.” (Colorblends)
TOP LEFT: Allium “Purple Sensation.” (Colorblends) TOP RIGHT: Allium karataviense. (Shutterstock) BOTTOM LEFT: Allium sphaerocephalon, also known as Drumstick allium. (Colorblends) BOTTOM RIGHT: Allium “Gladiator.” (Colorblends)
If your pockets are deeper, Gladiator is four feet tall with tight, rose-purple globes six inches across. Globemaster is another big flowered hybrid, with long blooming eight-inch lavender flowers. Ambassador is of the same ilk, but with blooms that are of a deep violet-purple. Large white flowering alliums are represented by Mount Everest, with a five-inch bloom on a 36-inch stem. White Giant is about seven inches across and rises to 40 inches or higher. Both bloom from May into June.
Allium karataviense is a low growing novelty, grown less for its dull white blooms and more for its straplike leaves, gray-green and mottled purple.
Lead illustration by Washington Post staff/Colorblends and Shutterstock. Icon illustrations by Jeannie Phan.
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