Pycnanthe-whom?

Lowell Halvorson

This year’s Perennial Plant of the Year award goes to an admittedly obscure selection: Pycnanthemum muticum. Attracting a wide range of beneficials is the pycnanthemum’s signature. Big bees, little bees (basically lots of bees), wasps, moths, caterpillars and beetles all enjoy the nectar along with the shelter the habit provides. It outperforms super-pollinators like salvia and makes a natural anchor in the high summer for any pollinator program out there.

Pictured: This species has an allium-style flowerhead. Photo courtesy of North Creek Nurseries. 

Among the pycnanthemums, P. muticum has the most ornamental value. Its silvery bracts surround the small flower as if it were a miniature poinsettia. Though the bracts are small, they tip the end of every stem, so an entire drift of P. muticum feels like it’s frosted with a creamy white topping. Hardy to Zone 4, it sits in a vertical column within a pot. When the plant matures, it reaches somewhere around 2- or 3-ft. tall. From far away, drifts look best; up close, it’s all about the stand and its bees.

If there’s any hesitation it’s because pycnanthemum is a false mint. An optimist would say, “It spreads, but not as much as spearmint.” A pessimist would say, “It’s a kaiju. It’s not Godzilla, but it’s still a kaiju.”

Personally, I think if you can handle monardas like Jacob Cline, you can handle pycnanthemums. They evolved in the same North American grasslands and meadows. In fact, entangling the two keeps them busy and slows both down a bit. Throw in an andropogon or solidago, and you have an easy-peasy corporate park.

Pycnanthemum already generates commercial revenue in the landscaping business. Corporate, hospitality and housing markets see major benefits: attractive drifts, bunches of bees, a long lifespan, no disease, and natural rain and deer resistance. It crowds out the weeds, cuts down on mulch and looks good from a long distance.

While P. muticum is available at a number of suppliers, pycnanthemum has interesting variations among its species. Two businesses actually have supplied a full pycnanthemum selection to the industry for decades.

Pizzo Native Plant Nursery in Illinois sells four species in 50-deep liners. They don’t have much trouble with spread in Midwestern gardens. Dry soil and lower natural rain keep the plant in check. Pizzo has also profiled the distinctive minty scent of each type for customers who value fragrance:

■ P. muticum—Spearmint, sweet mint fragrance

■ P. pilosum—Strong and spicy peppermint; smells like a candy cane

■ P. tenuifolium—Very faint mint scent with a hint of grass

■ P. virginianum—Lemony, citronella mint scent

North Creek Nurseries also sells in trays of 50 deep. They have one of the best photo libraries of pycnanthemums, a mix of flower mugshots and garden habit scenes that document the significant features of each species. Their website shows native mappings down to the county level and has a handy landscape calculator to figure out how many plants you need:

■ P. flexuosum—Better for shady gardens; slender leaves, no bracts, bigger flowers; core range in the Southeast leading up to the mountains (but not in them)

■ P. muticum—Tipped with silvery bracts; more compact habit; scattered widespread through the Eastern U.S.

■ P. pilosum—Fuzzy foliage; a little taller; no bracts, but a globe-ish flower; centered around Missouri and Illinois

■ P. tenuifolium—Dense foliage with slender thread-style leaves; no bracts, small flowers; pretty much everywhere in the East

When asking around, Prairie Moon Nursery comes up a lot. Their photo library is also excellent, especially the seed shots. They sell seed and liners directly to consumers, but they also provide a number of commercial growers with the seed they need to start their crops. Seed for pycnanthemum is considered easy to germinate—cast on top of the soil and expose to light.

From the breeding community comes Smokey Mountain Mint from Intrinsic Introductions. It’s a natural hybrid with the broad leaf and silver touches of P. muticum and the larger flowerheads of P. incanum. The quirk is its dark brown foliage—a little taller than P. muticum with the silver frosting on top. Only the bees know where the bronze came from. Good photos on the site show the plant well.

Pictured: P. muticum flowerhead with silvery bracts. Photo courtesy of Pizzo Native Plant Nursery. 

I should also point out that Mount Cuba initiated a trial garden test for the genus earlier this year. They spent 2024 bringing in material for a three-year run with a good number of choices in the ground. All this activity shows the bubbling interest in pycnanthemums over the past few years.

The Perennial Plant of the Year for 2025 hints at an underlying shift in the psyche of the American garden. P. muticum isn’t the classic pretty plant with the big fat flower. Its signature feature is the diverse set of pollinators drawn to the plant.

An ornamental’s job is to color the home, otherwise, our bedding gardens would be lined with alfalfa and soybeans. Here, P. muticum colors the home with butterflies, bees and beneficials. For the mainstream American garden, the PPOY award shows a rising desire to integrate the garden into the local ecosystem. Ornamental is still important, but a new value has joined it. This is why P. muticum, the most ornamental of the pycnanthemums, caught the brass ring at the PPA. GT 

Lowell Halvorson is a consultant and writer in Fairfield, Connecticut, for retail and wholesale horticulture, specializing in business development. He also covers the breeding community for GrowerTalks magazine. You can contact him at (203) 257-9345 or halvorson@triadicon.com.