Photo: no rights reservedCC0 1.0via iNaturalist
Slender Mountain Mint Plant Care
Pycnanthemum tenuifolium Schrad.
Updated · Sources · How we source care data
With its slender, lance-shaped leaves covered in fine hairs, this plant originates from North America and is highly sought after by plant collectors for its attractive foliage and delicate white flowers. Its unique appearance and ability to attract pollinators make it a standout addition to any garden or collection.
Every 7–10 days
Full sun to partial shade
60–80°F
40–70%
At a glance
How do you care for Slender Mountain Mint?
Water Slender Mountain Mint every 7–10 days, letting the top layer of soil dry out between waterings, and give it full sun to partial shade. It prefers temperatures of 60–80°F (16–27°C) and 40–70% humidity. Fertilize it every 6 months during the growing season.
Where Is the Slender Mountain Mint Native To?
What Is the Slender Mountain Mint?
Slender Mountain Mint (Pycnanthemum tenuifolium) belongs to the Lamiaceae family within the Pycnanthemum genus. Slender Mountain Mint is native to central and eastern North America. Slender Mountain Mint is also known as Narrowleaf Mountain Mint.
Slender Mountain Mint displays an upright, bushy perennial growth habit, reaching up to 2 ft tall with a spread of approximately 1.5 ft. Slender Mountain Mint produces clusters of small, tubular white or lavender flowers.
Leaf size: approximately 3 inches.
How Often Should You Water a Slender Mountain Mint?
Pycnanthemum tenuifolium requires watering every 7–10 days. Allow the top layer of soil to dry between waterings to prevent root rot. Reduce watering frequency during winter when growth slows.
Watering Frequency
Every 7–10 days
Let soil partially dry between waterings
What Light Does the Slender Mountain Mint Need?
Slender Mountain Mint thrives in full sun to partial shade.
Light Requirement
Full sun to partial shade
What Temperature and Humidity Does the Slender Mountain Mint Prefer?
Pycnanthemum tenuifolium grows best at temperatures of 60–80°F. Slender Mountain Mint prefers humidity levels of 40–70%.
Temperature
60–80°F
Humidity
40–70%
What Soil Mix Works Best for a Slender Mountain Mint?
Well-draining sandy loam with added organic matter for moisture retention. Good drainage is essential for Slender Mountain Mint to prevent waterlogging, which leads to root rot and fungal issues.
How Often Should You Fertilize a Slender Mountain Mint?
Feed Slender Mountain Mint every 6 months during the growing season (spring and summer) with a balanced fertilizer diluted to the strength on the label.
Pause feeding in autumn and winter, when growth slows, and never fertilize dry soil — water first.
Fertilizing
Every 6 months
During the growing season
The PlantoScan app can remind you when to water and when to fertilize each plant.
How Do You Repot a Slender Mountain Mint?
Repot every 2-3 years in early spring. Choose a pot one size larger than the current container, and ensure it has drainage holes to allow excess water to escape.
How Do You Propagate a Slender Mountain Mint?
Slender Mountain Mint can be propagated through seeds, division of clumps. Similar propagation techniques also apply to virginia mountain mint plant care, which shares the same genus.
Is the Slender Mountain Mint Toxic to Pets and Children?
Pet safety not verified
The ASPCA does not list Slender Mountain Mint, so we can't confirm whether it is safe for cats and dogs. Keep pets from chewing it as a precaution.
This is a general caution, not veterinary or medical advice. If your pet ate a plant, contact your vet or animal poison control.
See all plants toxic to cats and plants toxic to dogs.
What Pests and Diseases Affect the Slender Mountain Mint?
Slender Mountain Mint is susceptible to aphids, spider mites, whiteflies. Inspect the foliage regularly, especially along leaf undersides and stems. Treat infestations promptly with insecticidal soap or neem oil to prevent spread.
Yellow leaves, brown tips or drooping? See common plant problems and how to fix them.
What USDA Hardiness Zone Does the Slender Mountain Mint Need?
Slender Mountain Mint grows outdoors in USDA Zone 4a – 8b. It survives winters down to planting zone 4a. Slender Mountain Mint is native to central and eastern North America.
Hardiness Zone
Zone 4a – 8b
Keep exploring plants
Slender Mountain Mint is one of many species covered in the complete plant care and identification guide, which groups plants by genus, attribute, and popularity.
It belongs to the Pycnanthemum genus — compare its care with other Pycnanthemum species on PlantoScan.
Pycnanthemum is part of the Lamiaceae plant family — browse all Lamiaceae genera and species.
Slender Mountain Mint thrives in bright light and direct sun — see other bright-light plants.
More Pycnanthemum Species
Other Pycnanthemum species in PlantoScan's care catalogue share similar watering, light, and soil preferences:
Sources
- Scientific name & taxonomy: Pycnanthemum tenuifolium Schrad., family Lamiaceae (first published in Hort. Gott. : 10 (1809)) — World Flora Online record, IPNI name record.
- Pet toxicity: Pet safety not verified: the ASPCA does not list Slender Mountain Mint, so we can't confirm whether it is safe for cats and dogs. Checked against the ASPCA plant list; any other toxicity note on this page comes from PlantoScan's plant database.
- Photo: Public domain, CC0 1.0, iNaturalist — original.
- Hardiness zone: USDA Zone 4a – 8b, estimated from the plant's typical growing conditions.
- Care values(watering, light, temperature, humidity, soil, fertilizing): PlantoScan's plant database, filtered by automatic plausibility checks — values that fail them are hidden. How we source and check plant data.
Spotted a mistake? Email info@upvision.media with the page link — we check and correct reported errors.
Identify Plants Like the
Slender Mountain Mint Instantly
Scan any plant with your phone camera and get instant ID, care tips, water and fertilizer reminders, and health checks — all in one app.
Free
to download
iOS & Android
platforms
Light & dark
mode
100,000+
species