Crocosmia

Fundamental Facts

HARDINESS: Zones 5 to 8
PREFERRED SOIL pH: Near neutral
PREFERRED SOIL TYPE: Average
PREFERRED LIGHT: Sun
ATTRIBUTES: Vivid flowers atop graceful, sword-shaped leaves; for beds, cutting
SEASON OF INTEREST: Summer to early fall
FAVORITES: 'Lucifer', 'Jenny Bloom', George Davidson', Aurora', C. masonorum
QUIRKS: Flower spikes arch, and the individual florets face to the sides
GOOD NEIGHBORS: Ageratum, daylilies, petunias, zinnias
WHERE IT GROWS BEST: In sunny, well-drained locations
POTENTIAL PROBLEMS: Sparse blooms due to overcrowding; yellow leaves due to poor soil
RENEWING PLANTS: Lives up to 5 years; divide: discard old corms and replant young ones
CRITTER RESISTANCE: Excellent
PLANTING DEPTH: 5 in (12.7 cm)
SOURCE: Corms
DIMENSIONS: 3-4 ft (1-1.2 m) toll, 12 in (30.5 cm) wide

Crocosmia in the Landscape

When the show from your spring-flowering bulbs is long gone, you'll never miss them when the brilliant summer blossoms of crocosmia take center stage. Imagine arching flower spikes holding rows of vibrant trumpet-shaped florets that open gradually over several weeks, extending the show into early fall. Most often seen with bright red flowers, crocosmias also have yellow, orange, or bicolored blossoms. All are easy to grow and provide excellent cut flowers.

Crocosmias look best when grown in a grouping of several plants at least 2 ft (61 cm) wide. The flat, pointed, sword-shaped leaves don't look spindly when grouped, and a sizable planting also provides the scale needed for these 3-4 ft (1-1.2 m) tall, narrow plants. Because crocosmias bloom in such hot colors, they are best grown in the company of plants with quieter flowers. Summer annuals, such as white petunias, blue ageratum, or yellow zinnias make a fine frame for crocosmias and calm their fiery flowers. Crocosmias also make good partners for yellow-flowered daylilies and fall-blooming asters.

All in the Family

The saturated red flowers of 'Lucifer' is nearly synonymous with crocosmia, and it may be the hardiest and most reliable variety for Zones 5 and 6. 'Lucifer' is an old. reliable hybrid, as are yellow-flowered 'Jenny Bloom' and 'George Davidson'. Other good choices are 'Aurora' for orange flowers, 'Solfaterre' for apricot blooms, and 'His Majesty' for large red flowers with yellow centers.

The red-and-orange flowers of Crocosmia masonorum, which grow on 28 in (71.1 cm) tall stems, are particularly eye-catching. The individual flowers face upward, and look like summer-blooming daffodils.

Growing Crocosmia

Plant dormant crocosmia corms in early spring in a sunny, well-drained site. The corms are flattened disks with a slightly raised, pointed bud on the top of each one. Plant 5 corms per square foot and set them 5 in (12.7 cm) deep. Add organic matter if needed to improve the soil's texture, but don't worry about fussing over these plants. For best results, fertilize with a controlled-release, all-purpose plant food in early summer, following label directions. The leaves will yellow if soil nutrients are lacking. After the first freeze in late fall, snip off foliage at ground level and dispose of the leaves. In Zones 5 and 6, spread 4 in (10.2 cm) of straw, leaves, or other organic mulch over the dormant corms after the first freeze to insulate them from the ravages of winter.

Dig, divide, and replant every 4-5 years in early spring to avoid overcrowding, which leads to decreased flowering. When you lift the corms, you will see new ones atop the old ones. Break off the old, woody corms and replant only the young ones. They will bloom heavily the second year after division. Pests and diseases seldom trouble these care-free beauties.