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Slender Mountain Mint, Narrow-leaved Mountain Mint
Pycnanthemum tenuifolium

Family: Lamiaceae (lay-mee-AY-see-ee) (Info)
Genus: Pycnanthemum (pik-NAN-thee-mum) (Info)
Species: tenuifolium (ten-yoo-ih-FOH-lee-um) (Info)

Category:

Perennials

Height:

12-18 in. (30-45 cm)

18-24 in. (45-60 cm)

24-36 in. (60-90 cm)

Spacing:

18-24 in. (45-60 cm)

24-36 in. (60-90 cm)

Hardiness:

USDA Zone 5a: to -28.8 C (-20 F)

USDA Zone 5b: to -26.1 C (-15 F)

USDA Zone 6a: to -23.3 C (-10 F)

USDA Zone 6b: to -20.5 C (-5 F)

USDA Zone 7a: to -17.7 C (0 F)

USDA Zone 7b: to -14.9 C (5 F)

USDA Zone 8a: to -12.2 C (10 F)

USDA Zone 8b: to -9.4 C (15 F)

Sun Exposure:

Full Sun

Sun to Partial Shade

Danger:

Unknown - Tell us

Bloom Color:

White/Near White

Bloom Time:

Mid Summer

Late Summer/Early Fall

Foliage:

Grown for foliage

Herbaceous

Silver/Gray

Blue-Green

Smooth-Textured

Other details:

This plant is attractive to bees, butterflies and/or birds

Average Water Needs; Water regularly; do not overwater

Soil pH requirements:

5.1 to 5.5 (strongly acidic)

5.6 to 6.0 (acidic)

6.1 to 6.5 (mildly acidic)

6.6 to 7.5 (neutral)

7.6 to 7.8 (mildly alkaline)

Patent Information:

Non-patented

Propagation Methods:

From seed; direct sow outdoors in fall

Seed Collecting:

Unknown - Tell us

Regional

This plant has been said to grow in the following regions:

Marietta, Georgia

Lisle, Illinois

Minneapolis, Minnesota

Cole Camp, Missouri

Elsberry, Missouri

Lincoln, Nebraska

Glouster, Ohio

Royersford, Pennsylvania

West Chester, Pennsylvania

Fairfax, Virginia

Appleton, Wisconsin

show all

Gardeners' Notes:

3
positives
1
neutral
0
negatives
RatingContent
Positive

On Apr 25, 2011, Erutuon from Minneapolis, MN wrote:

I bought a mountain-mint at the Friends School Plant Sale (maybe in 2009) as Pycnanthemum flexuosum. I assume it's actually this species, since it was supposed to be Midwest-native, and photos of P. flexuosum look different from my plant.

Edit: This, like its relative Pycnanthemum virginianum (both of which I have), is an excellent plant for attracting wasps. During its bloom period I see many wasps on the flowers, mostly harmless species, not yellow jackets or hornets. The flowers are small enough that they can reach the nectar. I would recommend planting this to attract parasitic wasps to help control pests in the garden.

Positive

On May 21, 2010, papaverred from Fairfax, VA wrote:

Native, less-invasive (as mints go), can grow in deep shades, and an insect magnet. Tall 20 plant in the shade. Provides some height and texture in the woodland garden. Make sure to deadhead or else a carpet of seedlings will greet you in the spring.

Neutral

On May 20, 2008, podster from Deep East Texas, TX (Zone 8a) wrote:

I received this plant from a PDN fall plant sale last Nov. It was incredibly root bound so I repotted to a 1 gallon pot. In May, again unbelieveably root bound it went in ground. Located in a morning thru noon sunny spot with sand/gravel based soil as we receive drenchings.

It has a delicate foliage and a delicate fragrance. This plant is budding to bloom in the middle of May.

I hold reservations about rating this plant as I've not made a full year with it. I am on the southern hardiness zone for this plant. Also, for some gardeners, the root system might present a problem. Will try to update this in a year...

Positive

On Jun 21, 2005, PurplePansies from Deal, NJ (Zone 7a) wrote:

This plant is a U.S. native to the eastern portion of the United States. (to the Mississippi I think? :) )..... It is a tallish/gangly plant/mint. It likes partial sun/partial shade the best and can adapt to deeper shade and brighter/hotter sun. It is fairly easy to grow. It likes slightly less to well drained soil. But it doesn't like to dry out too much. It gets fairly unshowy white flowers in summer. (resembles and unshowy eupatorium).... The scent is not as strong as say spearmint or peppermint but is pleasent. It has a minty scent of its own but I think most closely resembles pennyroyal with a prevalent "tea" note. Not a showy plant, good for a wildflower/woodland garden. Said to (as most mints) have some medicinal properties (similar I think to peppermint? (medicinal attributes) .... read more