Among the greatest beneficiaries of this welcome resurgence are Canadian gardeners. Corms planted in spring will keep blooming all summer and produce many new corms by fall. In severely cold areas, these can be lifted like gladioli (but with less effort, since they're smaller) and stored for winter. Crocosmias also look great in containers, with progressive blooms from base to tip over five to eight weeks and cleanly dropped spent blossoms. When cut for bouquets, their blooms last up to two weeks.
In the garden, crocosmias fit in almost anywhere. Heat them up with similar warm tones of late-blooming daylilies, Rudbeckia spp., blanket flower (Gaillardia x grandiflora) and tickseed (Coreopsis spp.). Or simmer them down with contrasting blues and purples of clematis, perennial salvias, Russian sage (Perovskia atriplicifolia) or bluebeard (Caryopteris x clandonensis cvs.).
Smaller-flowered types such as 'Jenny Bloom' make jewel-like accents against subdued green foliage, but are equally effective mixed with multicoloured annuals and perennials. Larger, broader-leafed types such as 'Emily McKenzie' are right at home among bold tropicals—cannas, hibiscus and bougainvillea—but are also not out of place in a cottage garden setting. And all crocosmias keep perfect company with dahlias, especially those with dark foliage, such as 'Bishop of Llandaff'. Other dark-foliaged, sun-loving plants that make can't-miss companions include 'Diablo' ninebark (Physocarpus opulifolius 'Diablo') and New Zealand flax (Phormium tenax).
Since they bloom in late summer and don't require winter chilling, look for packaged corms in garden centres in spring, not fall; named cultivars are sold in summer already potted. Plant corms as soon as danger of hard frost is past, spacing them 10 to 15 centimetres apart and a good 10 centimetres deep. Add a pinch of bone meal under each corm to speed root growth.
In Zone 6 and up, crocosmias can be left in the ground indefinitely, especially if lightly mulched for winter. In Zone 5, a heavier mulch is necessary, as is the careful selection of cultivars (see New choices and old favourites). When flower production declines because of overcrowding, lift clumps in spring as soon as new growth appears, divide into sections and replant immediately.
In Zone 4 and below, corms must be grown in pots and treated as annuals or lifted and overwintered indoors. Do this after the first frost, dividing the clump into fist-sized sections and cutting the plant tops down to two to three centimetres tall. Shake off excess soil, but don't wash, clean or separate sections, since bare corms can shrivel in storage (they're never fully dormant). Dry the sections in an airy, shaded place for a few days, then store in dry peat moss in a cool area (10 to 15°C). In spring, separate corms and replant.
Top photo: Crocosmia 'Lucifer'