Jane's Garden 8/24/14: Choosing perennial Crocosomia

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Gardeners like perennial flowers that re-emerge each spring after winter dormancy. Most plants flower naturally in their particular season for about four weeks. The trick to having something in flower for every month is to select a variety of plants that will bloom at different times.

Crocosmia flowers from June to August in central Florida. It is hardy in zones 5 to 9 and does not need to be lifted for winter locally. A blanket of pine needle mulch is sufficient winter protection.

In the family Iridaceae, Crocosmia is an iris with flat, grass-like leaves in a clump at the base. There are seven species in the small genus, originally from South Africa in the Cape Floristic region. The leaves are alternate, lanceolate with parallel veins and entire, untoothed margins (edges). Dried leaves smell like saffron spice when steeped in boiling water.

The name Crocosmia is derived from the Greek word “krokos,” meaning “saffron” and sometimes translated as “odor.” Real saffron is made from crocus flowers, a related iris. Some gardeners are fascinated by the origins of plants and their names.

The best feature of Crocosmia is its spectacular display of summer flowers. They contain nectar that Ruby-throated Hummingbirds and large swallowtail butterflies find irresistible. Each plant sends up one arched, somewhat flexible flower stem 2 to 3 feet tall. This branches and from four to 20 six-petaled, sessile (without a flower stem) flowers hang down. The flowers can be so heavy as to bend the stalk to the ground after heavy rain.

The flower display can last several months in summer as a succession of plants each bloom. Crocosmia makes a long-lasting cut flower.

The tubular, nodding flowers are vivid, scarlet red to fiery orange. One bright hybrid is called ‘Lucifer.’ There are manmade yellow varieties. French botanists began hybridizing Crocosmia in the 1880s.

Common names in the United Kingdom include Montbretia, Coppertips and Falling Stars. In America, the botanical name is commonly used and easy to pronounce. The full scientific name is Crocosmia X crocosmiiflora, referring to its crossed hybrid status.

These irises grow from underground solid corms, similar to a bulb but without layers. The corms form vertical chains, with the youngest and smallest on the top closest to the soil surface. The contractile roots at the corm’s base pull the older corms deeper in the soil as they grow larger. The chains of corms are easily separated after the leaves die for winter dormancy. Dry leaves mark the corms as ready for division.

Plant corms 2 to 3 inches deep about 6 to 8 inches apart to allow room for natural spread for a few years. Masses of 12 or more corms produce a more attractive display than scattered individual flower stems. They flower best in full sun, but can tolerate high dappled shade, such as under Longleaf Pines. Soil should be well drained (sandy), humus-rich and moisture-retaining.

Crocosmia is a deciduous perennial well suited to Florida’s hot, humid summers and mild winters. There are potted plants awaiting adoption in my backyard nursery. Few retail outlets have caught on to gardeners’ desires for a wider variety of species.

Jane Weber is a professional gardener and consultant. Semi-retired, she grows thousands of native plants. Visitors are welcome to her Dunnellon, Marion County, garden. For an appointment, call 352-249-6899 or contact JWeber12385@gmail.com.