Gardening Articles: Flowers :: Bulbs
Hot Color: Crocosmia (page 3 of 3)
by Eileen Murray
In spring after the threat of frost has passed, plant the corms in clumps of 4 to 6 (except in regions where crocosmia becomes weedy), if you want an abundant display quickly. (Remember: You'll have to divide them in a few years to promote abundant bloom.) Set corms at a depth of 3 to 5 inches and space them 6 to 8 inches apart.
Growers in coastal and inland areas of southern California can plant as early as January through February. If you live in the Pacific Northwest, wait until April. The plants prefer full sun and moist, well-drained soil with average fertility and pH of about 6.5. Crocosmia tolerates partial shade, especially in the South and other hot areas. The plants are injured at temperatures below 28°F and need winter protection where temperatures fall below 10°F.
Most crocosmia varieties won't return where winter minimum temperatures fall below 20°F (zones 5a and colder). If you want to grow them in such areas, you have to dig up the corms after the first frost and store them in peat moss over the winter at about 50°F, as you would gladioli. However, the blaze of color that crocosmia sets in a garden may make that extra work worthwhile to you. Dusting lifted bulbs with sulfur helps to deter rot during storage. Don't let the stored corms dry out completely.
Lift and divide corms every three years or so to maintain vigorous blooming and to increase your supply of plants. Removing offsets found at the base of the main corm in the spring before growth begins is another method to produce more plants.
Pests. Spider mites can mar foliage, but they don't kill the plants. Generally, these plants are trouble-free. Some growers report that because crocosmia is related to gladioli, they may also be susceptible to gladiolus thrips.
Companion plants. The intense colors of crocosmia contrast well with hypericum, sundrops, baby's breath, coreopsis, Madonna lilies, rudbeckia, or white Shasta daisies. You could try unusual purple and reddish orange combinations of crocosmia with hydrangea, iris, or lavender.
Try planting it among orange and yellow azalea (Rhododendron species, hardy to zone 4), yellow and red weigela (W. florida, and other kinds hardy to zone 5), and other medium-sized shrubs in complementary colors. Deutzia (D. carnea 'Stellata') blooms earlier than crocosmia, extending successive flowerings of carmine blossoms in the garden from early spring into late summer.
Eileen Murray is a former editor of National Gardening magazine.
Photography by Suzanne DeJohn/National Gardening Association