Content Detail

In the summer, common mountain mint has white flowers flecked in purple that appear in dense clusters on top of tall stems that are covered in small, narrow leaves. When crushed, the leaves smell strongly of mint. The plant can grow well near streams and ponds, in rain gardens, herb gardens, native gardens, and pollinator gardens. This species is native to the Chicago region according to Swink and Wilhelm’s Plants of the Chicago Region and current research.

  • Family (English) Mint
  • Family (botanic) Lamiaceae (formerly Labiatae)
  • Tree or plant type Perennial
  • Native locale Chicago area, Illinois, North America
  • Size range Large plant (more than 24 inches)
  • Light exposure Full sun (6 hrs direct light daily), Partial sun / shade (4-6 hrs light daily)
  • Hardiness zones Zone 3, Zone 4, Zone 5 (Northern Illinois), Zone 6 (City of Chicago), Zone 7
  • Soil preference Moist, Sandy soil, well-drained soil, Wet soil
  • Tolerances clay soil, Occasional flooding, Wet sites
  • Season of interest midsummer, late summer
  • Flower color and fragrance White
  • Shape or form Narrow, Upright
  • Growth rate Fast, Moderate
  • Wildlife Butterflies, Insect pollinators

Size and method of spreading:

Common mountain mint is often between 2 to 3 feet tall and 1 to 1 ½ feet wide. This is a plant that spreads via underground stem structures (rhizomes). 

Native geographic location and habitat: (include C-value if appropriate)

The native range of common mountain mint includes the Eastern and Central United States. C Value: 5.

Attracts birds or pollinators: 

Common mountain mint attracts pollinating butterflies, bees, wasps, flies, and beetles. 

Leaf description:

Common mountain mint leaves are often up to one-half inch wide and 2 ½ inches long with pointed tips and rounded bases (linear or narrowly lanceolate). They are a grayish-green color. The leaves are stalkless (sessile) and attach to the stem in opposite pairs. When a leaf of common mountain mint sustains damage, it will emit a strong minty fragrance. 

Flower description:

Dense, flat-topped clusters of white flowers covered in purple spots develop at the terminal ends of common mountain mint stems. The individual flowers are approximately one-quarter inch across with a petallike, tubular structure (corolla) that divides into two lips (bilabiate) at the tip. The upper lip has two lobes that may appear as one, and the bottom lip is divided into three equally sized-lobes. Protruding from the center of the corolla are four long, white structures (filaments) topped with light to dark purple pollen structures (anthers) and another long white structure with a two-branched tip (style). Surrounding the base of each corolla is a small, leaflike tubular structure (calyx) with triangular lobes. The clusters can contain up to 50 small flowers each and are surrounded at the base by pointed, leaflike structures (bracts).

Fruit description:

Each flower produces tiny, dry fruit that splits into four single-seeded segments (schizocarps).

Plant Care:

Common mountain mint can be grown in clay, loam, sandy, or gravel soils that are well-draining and wet to moist. It is a species that may require some supplemental watering during drought conditions. 

List of pests, diseases, and tolerances:

No serious pest or disease issues are prevalent for common mountain mint, but foliar rust can become fatal for stressed plants.


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