Nepeta x faassenii
Vigorous, spreading members of the mint family with aromatic foliage. With the exception of catnip (Nepeta cataria), these plants are valuable for their spikes of two-lipped blue or blue-violet (or sometimes pink, white, or yellow) flowers. As soon as blossoms fade, shear plants back by half or cut faded flower stems to the ground to encourage rebloom. (Most species seed freely and can become invasive if spent flowers are not removed.)
Plants make attractive, informal low hedges or edgings. In winter or early spring, cut out last year’s growth to make way for new stems. At that time, you can also divide clumps for increase, though it’s easy to start new plants from cuttings (take them before flower buds form). When buying named varieties, be sure to obtain cutting-grown plants; seedlings vary in flower color and habit. In cold-winter climates, nepetas are occasionally used as a substitute for lavender (Lavandula) in borders and edgings. Most species resent heat combined with high humidity. In desert Zones 12 and 13, most are best treated as winter annuals. They tolerate regular moisture if soil is well drained.
Sterile hybrid of Nepeta racemosa and a European species; often sold as Nepeta mussinii. Soft, silvery gray-green, spreading mound grows to 1 ft. high, 1 1/2–2 ft. wide. Scallop-edged, heart-shaped gray-green leaves to 1 in. long. Attractive to some cats, who enjoy nibbling on and rolling in plantings; insert short sticks in the ground among the foliage to discourage cats and prevent destruction. Loose, lax spikes of 1/2-in., lavender-blue flowers in late spring, early summer.
Set plants 1–1 1/2 ft. apart for ground cover.
‘Select Blue’ has darker flowers than the species; ‘Snowflake’ has pure white blooms. ‘Dropmore’ grows to 1 1/2 ft. high and 3 ft. wide; it may be a hybrid involving another species.
European native for rock gardens or naturalizing. In bulb and leaf, resembles small hyacinth, but 10-i...
Grows 2 ft. tall. Smooth deep green leaves with yellow variegation have a spicy apple fragrance and fl...
Native to much of North America, the dramatic coreopsis tinctoria is slender, upright, 1 1/2 –3 ...