Home & Garden

Weekly planter: Agastache is an underexposed winner

The Easter Tiger Swallowtail is very fond of all of the hummingbird mints, including this Blue Fortune.
The Easter Tiger Swallowtail is very fond of all of the hummingbird mints, including this Blue Fortune. TNS

The agastache comes with a lot of common names like anise hyssop, giant hyssop and hummingbird mint, but, I assure you, “outstanding,” will be one of your adjectives if you grow it. About a year ago I wrote about Black Adder, which was and still is dazzling in our garden. It became the perfect backdrop in our daylily garden, helping show off all other colors.

We also had planted several Blue Fortune at the Coastal Georgia Botanical Gardens, and as anticipated they sent up spikes of lavender blue flowers from late spring until frost bringing in bees and butterflies like few other plants. They had no trouble reaching 36 inches in height, creating excitement in the garden by virtue of their spiky texture.

Both Blue Fortune and Black Adder are hybrids of the U.S. native Agastache foeniculum and Korean Agastache rugosa. This cross has given us perennials of participation. You will want to visit them often, even get a chair and stake out a position to watch and enjoy. The pollinator activity will amaze you, and for those of you who consider yourself to be a culinary artist, these are plants that will thrill with flavor.

Agastaches have become addicting for many horticulturists. Depending on the variety, they do well in hardiness zones 4 through 10, which includes almost all of South Florida except the Keys.

This year we added two more selections to our gardens and already they are living up to expectation. One is Blue Boa that won the “Too Good to Be True Award” at Colorado State University perennial trials. It was also a winner in North Carolina State University. Blue Boa is an unknown cross but absolutely stunning with deep violet blue flowers and dark green foliage. The larger flowers also attract hummingbirds and have a tantalizing fragrance. It is expected to be taller, topping out close to 4 feet.

The last one we planted is Agastache Violet Vision. This one is a unique cross with the Korean, A. rugosa and A. cusickii that is native to the western United States. It won best of Penn State Trials and features lush violet flowers on a more compact plant, all the while serving as a magnet for bees and butterflies.

To grow yours, select a site in full sun for best blooming and to keep the plants compact and better branched. The soil should be fertile and well drained. Wet feet will spell doom for the anise hyssop during the winter, so incorporate organic matter to loosen the soil or plant on raised beds. You will want to space plants 18 to 24 inches apart.

Though the plant is drought tolerant, watering during prolonged dry periods will pay dividends with added flower production. If you have an established clump, feed with spring growth using a light application of a slow-release fertilizer. Another application in mid-summer will keep the plants at peak for the fall.

All of the agastaches respond well to any cutting back, so feel free to do so if the plants begin to look a little leggy or you simply wish they were bushier. It’s funny, the branches I cut or prune always go unnoticed by others. In other words the plant still looks great.

These anise hyssops or hummingbird mints are a great choice for cottage gardens, herb gardens and the butterfly garden or backyard wildlife habitat. Despite being such persevering beautiful perennials, they are still not the staple they need to be at garden centers. This year, however, has been much better and well worth the search.

Norman Winter is director of the Coastal Georgia Botanical Gardens at the Historic Bamboo Farm, University of Georgia Cooperative Extension, and author of “Tough-as-Nails Flowers for the South.”