Most gardeners like surprises — such as seedlings that come back spontaneously a second year, or flowers that look as if the life had been sucked out of them by winter frost budding during the first warm days of spring.
The fall planting of a variety of bulbs can make for plenty of delightful surprises as the flowers start emerging during late winter. Thanks to the Bay Area’s Mediterranean-like climate, we can choose bulbs from other regions of the world with wet winters and dry, hot summers, including parts of Australia, Chile and South Africa.
Onions (from the genus Allium) are not just for eating; they include more than 500 species, many of them ornamental. These hardy, carefree plants can be incorporated into any garden setting. Not only do they add a spectacular architectural dimension to the garden, but they can be used in fresh flower arrangements or dried displays. Silver leafed Allium and the lime-green tones of Alchemilla mollis Allium combine wonderfully with old roses.
The three Allium varieties described below are easy to care for and last long in bouquets. When freshly cut, the stems do smell of onion, but that aroma goes away when the cut stem is submerged in water. The blossoms themselves generally have a light floral fragrance.
Allium aflatunense ‘Purple Sensation’ produces a ball of tiny violet-purple flowers tightly compressed into gorgeous baseball-size flowers atop 20- to 30-inch stems. This early summer bloomeroffers a great display. To make the color really pop, plant it among perennials of contrasting shades, such as Phlomis russeliana or ‘Moonshine’ yarrow.
Allium christophii yields starry, silver-amethyst blossoms that make one large, round spidery head about the size of a softball. This early-summer bloomer looks amazing amid ornamental grasses, and makes a spectacular addition to a bouquet. A native of Asia, it reaches a height of 12 to 20 inches.
Allium sphaerocephalon, often called ‘Drumstick allium,’ produces flowers that start out green and mature to a deep wine color. The tightly formed, quarter-size blossoms reach a height of 12 to 24 inches and look stunning amid Asiatic lilies or Hemerocallis. A native of Africa, Allium sphaerocephalon likes full sun, requires an average amount of water and will naturalize in the garden.
As with other bulbs, you should not cut Allium leaves when they start to fade. Instead, allow them to die naturally, which helps nourish the bulb for the coming year. Bulbs can be thinned if Allium starts taking over.