How to Care for Crocosmia

Crocosmia (Crocosmia x crocosmiiflora), also known as montbretia, is a sturdy summer bloomer that produces thick, strappy foliage topped with masses of bright, funnel-shaped flowers in shades of orange, yellow or red. At maturity, the flower stalks grow to heights of 2 to 3 feet. Native to South Africa, crocosmia flourishes in U.S. Department of Agriculture plant hardiness zones 6 through 10. In cooler climates, crocosmia's bulblike corms must be removed from the ground in autumn and stored for the winter.

Spade

Balanced garden fertilizer (all three numbers equal)

Organic mulch

Shovel

Paper bag or cardboard box

Sawdust or peat moss

Garden scissors

Plant crocosmia corms after the ground can be worked in springtime. Select a spot with well-drained soil, and work a balanced fertilizer into the soil before planting. A granular, slow-release, 10-10-10 fertilizer at a rate of 1 tablespoon per 3 square feet is sufficient. Plant the corms 6 to 8 inches apart and 3 to 5 inches deep. The plant likes full sunlight but tolerates light shade. In warmer climates, crocosmia can be planted in either fall or spring.

Water the crocosmia deeply at planting time, approximately 1 gallon of water per square foot, so the soil is saturated. After that time, crocosmia requires no supplemental irrigation until growth emerges in a few weeks. After growth appears, water crocosmia thoroughly to saturate the soil every seven to 10 days.

Spread 2 to 3 inches of organic mulch over the planting area after planting the crocosmia. Mulch helps retain the soil's moisture and keep soil temperatures from fluctuating. Mulch also helps deter growth of weeds that compete with crocosmia for moisture and nutrients.

Fertilize crocosmia, using a general-purpose garden fertilizer, when the shoots are 6 to 8 inches tall. Use a water-soluble fertilizer with all three numbers the same, such as 15-15-15. Mix 1 tablespoon of fertilizer with 1 gallon of water, and water thoroughly. Repeat the process again when the blooms appear.

Clip crocosmia blooms as often as desired for cut flower bouquets. Use sharp garden scissors, and sterilize the blades with household disinfectant before and after cutting to prevent spreading disease. Remove spent blooms regularly, by hand or with scissors, to promote more blooms. After blooming, leave the foliage. Let it die down naturally on its own. This helps refuel the corms for next year.

Divide crocosmia every three to four years to keep the plant from becoming overcrowded. Don't divide more often; crocosmia blooms most profusely when slightly crowded. Dig the entire clump in autumn with a garden spade, then divide it into smaller sections. Wear gloves, gently pull the corms apart, and replant the smaller sections in a prepared spot. Crocosmia has few pests or diseases, but throw away any soft or damaged corms that look unhealthy.

Dig crocosmia corms after the foliage dies down in autumn, if you live in a climate cooler than USDA zone 6. Place the corms in a sheltered spot to dry for one or two days, then place the corms in a paper bag or cardboard box filled with sawdust or peat moss. Store the bulbs in a cool, dry room where temperatures will stay between 35 and 45 degrees Fahrenheit for the winter months. When spring arrives, replant the crocosmia corms in your garden.