HARDINESS: Zones 4 to 9
PREFERRED SOIL pH: Neutral
PREFERRED SOIL TYPE: Average, well-drained
PREFERRED LIGHT: Sun to partial shade
ATTRIBUTES: Profuse flowers on compact plants; for edging, beds, hedges
SEASON OF INTEREST: Late spring through summer
FAVORITES: 'Dropmore', 'Snowflake', 'Six Hills Giant', 'Dawn to Dusk', 'Walker's Low'
QUIRKS: Grows poorly in wet soil and when overfertilized
GOOD NEIGHBORS: Herbs, roses, yarrow, verbena
WHERE IT GROWS BEST: Sun, average soil
POTENTIAL PROBLEMS: Virtually pest and disease free; grows poorly in hot, humid weather
RENEWING PLANTS: Plants live many years; divide every 3 years or when clumps start to die
CRITTER RESISTANCE: Good
DIMENSIONS: 1-3 ft (0.3-1 m) high, 1-3 ft (0.3-1 m) wide
Catmint in the Landscape
If you want a care-free perennial plant loaded with white or blue-hued flowers, opt for catmint. In summer, its profuse wands of small, trumpet-shaped, flowers cover the compact 1-3 ft (0.3-1 m) tall plants, contrasting nicely with the silver gray foliage. Catmint should not be confused with catnip (Nepew catena), which, unlike catmint, is fascinating to felines but makes a comparatively unexciting garden plant for humans.
Catmint works well anywhere you want strong color in early summer, whether in an herb garden, along a path, or at the feet of rose bushes. After the prolific blooms pass, the dense, velvety, lighdy fragrant foliage persists the rest of the season. If you want catmint to rebloom, cut it back by a third right after the first round of flowers fades. For a while, you'll have a small shrubby-looking plant. By late summer or early fall, that little bush will stage a flowery encore.
Cats of a Different Color
Plant breeders have expanded catmint's color range and created plants of varying statures to give gardeners more flexibility with this handsome, durable plant. 'Dropmore', at only 1 ft (0.3 m) tall, has deep lavender flowers that are larger than those of other varieties. 'Snowflake' is similar in stature but has white flowers, while the blossoms of the 3 ft (1 m) tall 'Dawn to Dusk' are light pink. Perhaps the best-known catmint is 3 ft (1 m) tall 'Six Hills Giant', a lush beauty with violet-blue flowers, splendid for use as a low-maintenance, seasonal hedge. Standing equally tall, despite its name, 'Walker's Low' has the benefit of forming a nice round orb that doesn't part in the center under the weight of its own flowers, making it ideal for use as a hedge.
Once established, catmint is a tough plant well adapted to poor, gritty soil. However, it grows best in soil of average fertility in full sun or with a little afternoon shade in hot-summer areas. Mulch and fertilizer are unnecessary. In fact, fertilizer can cause catmint to stretch, growing unattractively long and lanky. Although catmint is in the mint family and will grow in average-to-moist soil, it's not a water guzzler like its relatives. Instead, once established, it is admirably drought tolerant, and too much water can also cause stretching and flopping. It's virtually pest and disease free.
Start with small nursery plants. Dig a hole as deep and twice as wide as the root ball and gently pull the roots loose so they can grow freely. Set the plant into the hole and fill with crumbly soil. After planting, water well to eliminate air pockets, and water every few days until you see new growth. From then on, water only if the plants begin to wilt in the heat. Established plantings survive for years. Divide clumps only when the central portions of plant clumps begin to stop flowering and die, or if you want to increase your stock.