Recently announced as the bulb of the year for 2016, the Ornamental Onion or Allium, has finally come into its own. Just ten years ago, these bulbs were rarely seen in gardens, but now I see them everywhere I turn. And the colors, shapes, and sizes that they come in is phenomenal. When the leaves start to fall, start planting these beauties, and if you can’t find them in local nurseries, a whole range of colors and sizes are available online. Native to the mountains of central Asia, where the winters are cold and the soil is thin and porous, Alliums like to be kept on the dry side. One of the oldest cultivated plants, first as an edible bulb, and then later in the 1800’s as an ornamental and highly coveted by plant hunters.
With their plump flower heads held on hollow stems above strappy basal leaves, hovering like purple clouds, Alliums are one of the highlights of the late spring into summer garden. If you select carefully, you could have Alliums bloom for over 20 weeks in the garden. Starting in May with Allium karataviense (Kazakhsatan onion) to October-blooming Allium thunbergii ‘Ozawa’, Alliums will keep your yard blooming all season long.
Alliums are easy care, a snap to grow, and last for weeks in the garden in flower and months in the garden in the form of decorative seed heads. And did I mention, deer, voles, moles, and rabbits, leave them strictly alone? The one drawback is that the larger ones like Globemaster can set you back an average of $8 a bulb. Large eight to ten inch lilac orbs will reward you in the late spring if you thought far enough ahead and set aside some bucks to bankroll this investment. They last for years and years.
Odorless unless you step on their leaves or foliage, they will emit a sulfurous bitter-tasting compound, thus the deer repelling effect. In contrast, the flowers produce a sweet nectar that draws bees and other pollinators, a perfect plant!
The strappy foliage is beautiful when the flower is blooming, but will wither and disappear quickly as the flower matures. The seed heads as they dry on the stem make a statement in the garden, and in the fall, they become little tumbleweeds rolling around like lost puppies.
Plant bulbs at 2½ times their own depth in autumn and space them about 8 inches apart. Make sure the soil is porous and well draining and avoid irrigated gardens as they will just rot. Full sun is best, but partial sun will do. That’s all there is to it and you will have these gems come up year after year.
Coming in a broad palette of colors, heights, bloom times and flower forms, Alliums are plants with tough constitutions. Excellent flowers for fresh or dried bouquets, even fully planted gardens can accommodate these bulbs which need little room. I find them good companions to grasses, and large leaved plants where the dried seed heads contrast nicely with the foliage.
Used in flower arrangements and as decorations in the house, the seed heads last several seasons.
Alliums multiply naturally and prefer to be left untouched in the same area for years. There are no serious diseases or insect pests that bother them.
I often wonder why Alliums or Ornamental Onions are not more widely planted, and I think it is a naming problem. Ornamental Onions conjures up a supermarket food and not a beautiful bulb like a tulip or daffodil. Alliums are the best kept secret of the bulb world and once you start planting them, you will add to your collection every year. For more information about varieties and history, go to National Garden Bureau.