Ontario Native Mountain Mints
Mountain mints are native plants in the mint family, valued by gardeners for their resilience, ease of growth and very high pollinator value. They are some of the most reliable and low-maintenance native plants, thriving in various soils and conditions with minimal care. Each species — from the silvery, velvety Hoary Mountain Mint to the airy and graceful Slender Mountain Mint — brings unique traits that make them useful in a variety of garden settings. Their dense clusters of white flowers and fragrant foliage are unmatched in their ability to attract bees, butterflies, and other pollinators. Whether you are planting a rain garden, praire garden, meadow garden or naturalizing, there is likely a mountain mint suited to your needs.
Hoary Mountain Mint (Pycnanthemum incanum)
Sun to part sun | 90cm tall | Average to dry | Sand, clay, gravelly/rocky | Prairies, open woods, dry oak woodlands |
Hoary mountain mint could be grown for its bushy form and beautiful silvery-white foliage alone! That being said, you’ll also want to grow it for its high wildlife value, showy flowers, extended seasonal interest and ability to tolerate a variety of tough growing conditions such as that dry, sun-baked garden. Ideal for prairie gardens, meadow gardens and natural garden design.
Appearance:
Hoary mountain mint is a perennial with a bushy, upright growth habit and strong, square stems. The upper leaves have an attractive silver-white patina, giving the plant a hoary look. Leaves are wonderfully fragrant, smelling of mint. Stems are topped by clusters of tightly packed, tubular flowers ranging in colour from white to lavender and bloom for over a month, starting in mid-summer. Compared to other mountain mints that usually sport white blooms, hoary mountain mint usually has larger and deeper purple blooms. Flowers fade into attractive seed heads that stand tall through the winter months to add a silvery-grey colour and texture to the winter garden.
How to grow:
Hoary mountain mint is easily and reliably grown in average to dry conditions in full sun and most well-drained soil types, including heavy clay! It is drought tolerant and perfect for hot dry locations with poor soil. Part shade is tolerated but flowering and vigor will be reduced. Speaking of vigour, this mountain mint will spread quickly by rhizomes to form colonies so it may not be ideal for small gardens. That being said, the rhizomes are shallow and easily pulled out to control spread. Keep in mind that rich soil or lack of competition from other plants may result in floppy plants.
Hoary mountain mint is easily propagated by divisions or seeds. The minty taste of the leaves makes the foliage highly deer-resistant so you may want to plant it strategically to deter deer from other plants.
Ecology:
Hoary mountain mint is a pollinator powerhouse! Native bees, butterflies and moths flock to the blooms as do predatory insects. Endangered in Ontario mainly due to fire suppression and invasive species.
Slender Mountain Mint (Pycnanthemum tenuifolium)
Sun to part sun | 60-90cm tall | dry to average soil | Sand, loam, clay, gravelly/rocky | Prairies, meadows, open woods |
Slender mountain mint is valued by native gardeners for its reliability, ease of growth and ability to attract copious numbers of pollinators. The clusters of elegant white flowers light up prairie gardens, meadow gardens and naturalization projects for weeks. Despite having ‘mint’ in its name, it isn’t as aggressive as you may think and is suitable for most garden settings.
Appearance:
Slender mountain mint looks good all year round. It has a strong, upright form and is heavily branched, giving it a bushy look. Its narrow, needle-like leaves add a soft texture to the garden and differentiate it from other mountain mints. For several weeks in late summer, clusters of white blooms with lavender spots sit atop the stems, lending an elegant aesthetic to the garden. Flowers mature into attractive seed heads that stand strong through the winter months to add interest and texture.
How to grow:
Slender mountain mint thrives in average to slightly dry conditions, adapting to a variety of well-drained soil types including clay and compacted soils. It can tolerate occasional wet conditions. Part shade is tolerated but flowering may be reduced. Though not as aggressive as other mountain mints, it still spreads by rhizomes to form dense colonies. That being said, it still fits in well with home landscapes. The minty aroma of the plant makes it highly deer-resistant.
Ecology:
The flowers attract an impressive number of pollinators. Expect to see long-tongued bees, short-tongued bees, butterflies, wasps, skippers and beetles. The wasp species who visit are completely non-aggressive while they forage for nectar and pollen.
Whorled Mountain Mint (Pycnanthemum verticillatum)
Full sun to part sun | 60-120cm tall | Moist to dry | Sand, loam, clay | Prairies, open woods, rocky outcrops, shorelines |
Whorled mountain mint adds a refined look to the garden with its bushy form, greyish-green leaves and clusters of long-lasting white flowers. Strong winter interest and high wildlife value make this a must-have plant for any garden that suits its growing needs. Due to its tendency to spread, it is best grown in a meadow-type garden, rain garden or naturalistic planting rather than a formal garden.
Appearance:
Whorled mountain mint looks great all year long. It has a strong, upright form with densely hairy leaves, giving the plant a soft, fuzzy texture and a green-grey colour. In mid to late summer, upper stems branch out, displaying flower heads densely packed with white flowers with purple dots. Flowers mature into attractive, greyish-brown seed heads that persist into the winter months to extend seasonal interest. During drought, the lower leaves of the plant may fall off.
How to grow:
Whorled mountain mint does best in moist to slightly dry, fertile loams in full sun. That being said, it's adaptable to moisture conditions and will tolerate dry conditions once established. Part shade is tolerated but its flowering and form are best in full sun. Poor and rocky soil is tolerated. This is typically a clump-forming plant but may spread into large clumps by rhizomes. Cut back roots in the spring to control spread or pair the plant with plants of a similar spreading habit. This plant is easy to divide and transplant. Grows well with taller plants.
Ecology:
The flowers support an incredible diversity of pollinators including native bees, flies, solitary wasps, butterflies, skippers and moths. Deer and rabbits avoid the plant due to its minty aroma.
Virginia Mountain Mint (Pycnanthemum virginianum)
Sun to part shade | 90cm tall | Sand, loam, clay, gravel | Medium to moist | Mesic prairies, stream edges, marshes, wet meadows |
Virginia mountain mint is valued by gardeners and pollinators alike for its elegant, nectar-rich blooms. It makes an ideal companion for a variety of meadow and prairie species. This one is less aggressive than the other mountain mints and tolerates more shade. It is ideal for rain gardens, shoreline plantings and semi-formal landscapes.
Appearance:
Virginia mountain mint is a stout, upright plant with highly branched upper stems, giving it a bushy look. Its slender, dark green foliage lends an attractive texture to the garden even while the plant is not in bloom. Note that the lower leaves may fall off during drought. Stems are topped with clusters of tightly packed white flowers dotted with purple. They bloom profusely from mid-summer into early fall. The leaves turn to attractive shades of yellow in the fall. Flowers fade into attractive grey-brown seed heads that persist well into the winter months to extend seasonal interest. Virginia mountain mint is best grown in large clumps or drifts to mimic the colonies it forms in the wild.
How to grow:
Virginia mountain mint is very easy to grow due to its adaptability. It thrives in moist, well-drained soils in full to part sun. Drought and seasonal flooding are tolerated once the plant has been established. It will tolerate part shade, with reduced flowering, and is the most shade-tolerant of the mountain mints. Virginia mountain mint typically maintains a clumping form, spreading outwards at a moderate rate by rhizomes and is the least aggressive of the mountain mints. If spread becomes problematic, plant your garden more densely or use a spade to cut off the spreading rhizomes once each spring. Established clumps are easily divided and transplanted.
Ecology:
Virginia mountain mint flowers support many pollinators, including native bees, solitary wasps, butterflies and beetles. The plant is resistant to deer and rabbit browse.
