Purple firespike (Odontonema callistachyum) is a vigorous, multi-stemmed shrub from Mexico and Central America that produces large, purple flower spikes (i.e., inflorescences) from October to July. The individual flowers are small (ca. 1” long) and born profusely on elongate spikes that can reach 2 feet or more in length. The small pinkish-purple flowers contrast nicely against the darker purple subtending bracts and produce copious nectar, attracting butterflies and hummingbirds throughout winter and spring.
In its native habitat, and in the absence of freezing temperatures, purple firespike is evergreen and can flower year-round. Plants typically reach 8-10 feet in height, which makes them excellent in foundation plantings, and as hedges and screens. Purple firespike is vigorous and can grow 6-8 feet in a single season, requiring occasional pruning, particularly in more formal and/or smaller landscapes. Maintenance pruning can be performed at any time of the year, while rejuvenation pruning (i.e., pruning to within a foot or two of ground level) is best done in late summer or early fall after cessation of flowering.
Purple firespike is reliably hardy in south Florida, but hard freezes will occasionally kill the plant to the ground in central Florida. In north Florida, purple firespike is probably best treated as a die-back shrub (i.e., root hardy perennial), but should still do well even in warmer areas of zone 8 and can be mulched in late fall or early winter to help insulate roots.
Purple firespike prefers moist, well-drained soils and is moderately drought tolerant once established. Plants may benefit from supplemental fertilization in sandy soils, but are not heavy feeders and should do well in most central Florida soils. In its natural habitat, purple firespike frequently occurs in forest understories; however, in the landscape plants perform best in full to part sun. Plants at Bok Tower Gardens do well in full sun but are happiest when given a brief respite from our hot, afternoon sun.
This blog was written by Patrick Lynch, Plant Records Curator and photographed by Cassidy Jones, Social Media Coordinator