Alliums are a members of the lily family, containing 1100 species, including the edible kinds that you add to your burgers and salads. In the ornamental flower world include spring- blooming bulbs, culinary herbs and durable foliage and bountiful summer flowers.

Whether your summer garden is located in a challenging part of the U.S. such as Texas or Oklahoma or a moist humus-rich ground in New York or Virginia, take a peek at the perennial gems in the onion family (genus Allium). Recently, Richard Hawke, Director of Ornamental Plant Research at the Chicago Botanical Gardens CBG), published the top-rated rhizomatous alliums in the Midwest region (see below).

Rhizomatous alliums just ask for sun and well-drained soil. All are all drought resistant and thrive on dry sites. They are all highly drought tolerant, especially after plants have established themselves their first season.  Pest and disease issues are usually rare. Watch for occasional leaf spots, molds, thrips, and onion flies. Allium plantings are busy with beneficial insect life, covered by numerous bees and butterfly species. And deer don’t dig onions or chives.

I have a number of favorites, many of them on the “CBG’s Best Of” listing which appears in the August ‘22 Fine Gardening Issue. Let me start with A. ‘Millenium’, Perennial Plant of the Year winner in 2018. It produces masses of 2.5″ rosy-purple flowers above the dark green foliage in midsummer.

A. ‘Windy City’- thin dark-green leaves provide a dramatic backdrop for 2″ lavender-purple flower clusters on strong, dark stems. Spent flowers persist for winter interest, and are near-sterile, meaning very little seed. This compact variety is perfect for small spaces such as in a rock garden. 

A. tanguticum ‘Summer Beauty’ – long-blooming ornamental onion that produces showy, globe-shape 2” lavender-pink blooms in mid-summer and shiny deep green throughout the season.

In the CBG evaluation, three rhizomatous alliums were highly mentioned but not rated:

A. ‘Serendipity’ – sport of ‘Millenium’ great stuts attractive blue green foliage. Globe-like, 2.5” rosy-purple blooms that flower abundantly in mid to late summer. 

A. ‘Big Beauty’- soft pink 3” flowers with gray-green foliage in early to mid-summer.

A. ‘Lavander Bubbles’ – blooms a month later than ‘Millenium’ with darker shade of 3″ purple floral globes above attractive glaucous blue-green foliage.

Read the full CBG report in Fine Gardening magazine (August 2022 issue).