![Two photos show an overview, left, and close-up, right, of a plant with delicate silvery-white flowers and green stems and leaves.](/remote/aHR0cHM6Ly9naWVjZG4uYmxvYi5jb3JlLndpbmRvd3MubmV0L2ZpbGV1cGxvYWRzL2ltYWdlLzIwMjQvMDgvMDIvbW91bnRhaW5taW50LXBwb3kuanBn.Sv1TMdO2F3E.jpg?w=948&h=533&format=webp&mode=pad&anchor=middlecenter&scale=both&bgcolor=F0F1F2)
Photos courtesy of Chicago Botanic Garden
The 2025 Perennial Plant of the Year is Pycnanthemum muticum, the Perennial Plant Association announced at the 2024 PPA National Symposium on July 31 in Asheville, North Carolina.
Pycnanthemum muticum, voted the 2025 PPOY by PPA members, is known as clustered mountain mint, blunt mountain mint or short-toothed mountain mint and is native to meadows and open woodlands across much of the eastern United States west to Texas. It is not a true mint (Mentha spp.) but belongs to the same family and has similarly scented leaves.
The PPA said Pycnanthemum muticum is a must-have for pollinator gardens, with heads of tiny white to light pink blooms attracting butterflies, wasps and bees from July to September. Although the flowers are inconspicuous, they are surrounded by silver bracts that give the illusion of frost in summer and can persist for months.
“While not necessarily the show-stopper with large eye-catching flowers, it’s a great pollinator plant, adding to its supporting role credentials," says Kyle Lambert, perennial and rose manager at The Growing Place Garden Center. "It provides a nice textural contrast to finer leaved plants and has a minty fragrance when touched. Silvery bracts top the plant when in bloom, adding to the interest. It is less of a spreader when planted in a lean, well-drained location, and it looks great all season with no effort.”
Clustered mountain mint is a tough and adaptable perennial native with no serious disease issues, and due to its aromatic foliage, it is unpalatable to deer and rabbits. Branched, vertical stems grow two to three feet tall and form a dense, weed-suppressing clump. It spreads through underground rhizomes and can be aggressive in moist conditions, although it is not invasive to the degree of true mints.
Pycnanthemum muticum prefers an area where it can freely naturalize and mingle among other plants. Its silver sheen plays well with other flower colors and contrasts wonderfully with plants with dark foliage. Some good companions include black-eyed Susans (Rudbeckia spp.), bee balms (Monarda spp.), blazing stars (Liatris spp.), Joe Pye weeds (Eutrochium spp.) and native grasses such as little bluestem (Schizachyrium scoparium) and switchgrass (Panicum virgatum).
Hardy in USDA Zones 4 to 8, Pycnanthemum muticum does well in full sun to part shade and grows 24 to 36 inches tall, spreading widely by rhizomes.
Clustered mountain mint can spread aggressively, especially in wet soils. Rhizomes are easy to control by cutting them to the desired size with a spade and pulling the shoots by hand in spring. Seed heads may be left until early spring for winter interest. It tolerates heat and drought once established, with no serious pest or disease issues.
It prefers medium to high moisture, fertile, well-draining soils and tolerates clay soils, but it's less tolerant of drought than most other mountain mints.
For growers: Pot in fall to bulk/overwinter for early spring sales. Pot in early spring for late spring/early summer sales (does not require vernalization). Finishing schedule for 1-gallon: 4 to 6 weeks from a 32-cell liner; 6 to 9 weeks from a 50 or a 72. Shear in spring (repeatedly, if necessary).
“If you are looking to attract pollinators en masse to your garden, look no further than Pycnanthemum muticum," says Sam Hoadley, horticulture research manager at Mt. Cuba Center. "It is invaluable to gardeners thanks to its beauty, vigor, adaptability and disease and herbivore resistance.”
The Perennial Plant of the Year program began in 1990 to showcase a perennial that stands out among its competitors. Selected perennials are suitable for a wide range of growing climates, require low maintenance, have multiple-season interest and are relatively pest/disease-free.
The Perennial Plant Association Board of Directors reviews the nominated perennials and selects three or four perennials to be placed on a voting ballot. PPA members vote for the Perennial Plant of the Year and nominate additional plants for the following year’s ballot. PPA members also have access to several marketing resources to assist with promoting the Perennial Plant of the Year.
For more information on Pycnanthemum muticum, visit perennialplant.org/page/2025PPOY.
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