Depend on allamandas for plentiful flowers
Allamandas have enlivened Florida’s landscapes with their bright blossoms for more than a century. The most popular allamanda (A. cathartica), though undeniably beautiful, is the least appropriate for most gardens. Misleadingly labeled ‘’shrub allamanda,’’ this vigorous Tropical American species climbs up to 20 feet high by weaving its stems through the branches of nearby shrubs and trees. If sited where it cannot climb, however, this yellow-blossomed, would-be vine demands frequent pruning to prevent an unkempt appearance.
Much more suitable for local landscapes is Allamanda schottii, also — unfortunately — called shrub allamanda or bush allamanda. A true shrub that grows 4 to 6 feet tall and wide in sun, this Brazilian species with trumpet-shaped flowers has slightly smaller leaves and blossoms and is less sensitive to frosts and freezes. Indeed, specimens in sheltered locations may bloom year-round. Like all allamandas, this plant’s foliage is mildly toxic.
Purple allamanda (A. violacea), also Brazilian, features a growth habit that’s in between its two yellow-blossomed brethren. This handsome species, with light-purple, bell-shaped flowers, grows 5 to 10 feet tall and — if given the opportunity — will clamber. Due to its smaller stature, purple allamanda is much easier to maintain as a shrub than A. cathartica.
Confusingly, purple allamanda is sometimes called chocolate allamanda as well as Cherries Jubilee allamanda. Such overlapping and blended names can make it difficult to distinguish species and varieties. Among options, however, are white-flowered forms including Allamanda Cream and Allamanda x Alba. There’s also a lovely gold-tinged variety called Indonesian Sunset.
Regardless of their names, all Allamandas demand bright light and well-drained locations. Enriching sites with organic matter and keeping them mulched encourages healthy growth and abundant flowers.
Brazil isn’t the only source of Allamandas. Interestingly, a smaller, distant relative called wild allamanda (Pentalinon luteum) has become increasingly popular. Not a true Allamanda, this native plant does, however, belong to the same vast Apocynaceae family. Labeling, however, is still problematic, with this plant often listed as yellow mandevilla.
Wild allamanda, ranging from South Florida to South America, is a sprawling shrub or vine with stems that grow 4 to 12 feet long in full or part-day sun. It features 3-inch yellow, trumpet-shaped flowers nearly year-round if shielded from north and northwest winds. Wild allamanda thrives even in poor soil and is drought tolerant. As with true Allamandas, it’s mildly toxic and propagated with warm-season cuttings.