Culture
Grow in medium moisture, moderately fertile, well-drained soil in full sun to part shade. Prefers full sun, but appreciates part shade in hot summer climates. Plant corms in spring after last frost date approximately 3-4” deep and 6” apart. Not reliably winter hardy in USDA Zone 5 where it needs a protected location and winter mulch. In order to insure winter survival in USDA Zone 5 and perhaps Zone 6A, digging up the corms in fall and storing them in a dry medium over winter (in somewhat the same manner as gladiolus) is an option that may be considered.
Noteworthy Characteristics
Crocosmia is a genus of about 7 species of cormous plants from grasslands in South Africa. They are good fresh cut flowers which are frequently used in commercial flower arrangements.
Genus name comes from the Greek words krokos meaning saffron and osme meaning a smell for the smell of dried flowers steeped in warm water.
'Cropom' is an upright selection of montbretia (Crocosmia x crocosmiiflora) that features 1.75" diameter, bright orange flowers with red markings held on gently arching flowering stalks above narrow, sword-like foliage. Mature clumps will reach up to 3' tall with a similar spread. Commonly found in nurseries and garden centers sold under the name IRISH SUNSET. Plant patent number PP14885 applies to this cultivar.
Problems
Spider mites can cause significant damage to the foliage, and, if left unchecked, can impair normal flowering. Rabbits will eat the foliage and can impede blooming. Winter hardiness is a concern in the St. Louis area.
Uses
Best when planted in clumps of 12 or more. Provides color and contrast to the perennial border. May be grown in containers where lifting in winter is perhaps easier.