Pycnanthemum incanum
Common Name: mountain mint
Type: Herbaceous perennial
Family: Lamiaceae
Native Range: Eastern United States
Zone: 4 to 8
Height: 2.00 to 3.00 feet
Spread: 3.00 to 4.00 feet
Bloom Time: July to September
Bloom Description: White sometimes tinged with lavender
Sun: Full sun to part shade
Water: Dry to medium
Maintenance: Low
Suggested Use: Naturalize
Flower: Showy
Leaf: Fragrant
Attracts: Butterflies
Tolerate: Drought, Erosion, Dry Soil

Culture

Easily grown in average, dry to medium, well-drained soils in full sun to part shade. Best flowering in full sun. A vigorous and sometimes aggressive grower which spreads by long rhizomes. If naturalizing is unwanted, prune roots in spring with a spade to keep clumps from spreading.

Noteworthy Characteristics

Pycnanthemum incanum, commonly called hoary mountain mint, is best distinguished by the hoary/whitish appearance of the upper leaves and bracts beneath the tiered flower clusters. This is an erect, many-branched perennial that typically grows 2-3' tall on square stems. Broad-ovate, toothed leaves (1.5 to 3" long) are hoary beneath. Small, two-lipped, white (sometimes lavender-tinged) flowers with purple spotting on the lower lip bloom in mid to late summer in tiered terminal and upper axillary clusters (to 1.5" wide). All parts of the plant emit a strong, spearmint-like aroma when crushed. Leaves have been used to flavor teas. Flowers are a favorite of butterflies, moths and beneficial predatory wasps.

Genus name comes from Greek pyknos meaning dense and anthos meaning flower for its densely packed flowers.

Specific epithet means hoary.

The common name of mountain mint for this mint family member is somewhat misleading since the plant typically grows in dry open woods, thickets and fields in the eastern United States from Maine to Illinois south to eastern Texas and northern Florida.

Problems

No serious insect or disease problems. Plants can spread aggressively.

Garden Uses

Best when allowed to spread in naturalized areas, native plant gardens, dry meadows or herb gardens. May be planted in border perimeters as long as spread is monitored.