pronounced: KOST-uss bar-BAY-tuss
Costus is derived from the Sanskrit name for the species, Kushtha; barbatus is Latin for ‘having a beard; woolly, downy’. The underside of the leaves of this species is velvety.
The Costaceae are related to the true gingers, and were originally part of the ginger family (Zingiberaceae), but have now been re-classified into their own family. It is hard to make generalizations about them, because they are so varied. Some like full sun, some like shade, some are cold-hardy and some are strictly tropical. Most of them are great landscaping plants. They are fast-growing and quick to flower, and are much more forgiving of poor soil than heliconias. Costus flowers will often last up to 9 months on the plant. Costus are well-behaved and easy to remove. This makes them useful if you want a quick fill in the garden while other plants are maturing.
This plant, a native of Costa Rica, grows in a nice clump, up to about 2 m tall and about the same width. The foliage is attractive, with dark green elliptic leaves that are fuzzy underneath, spirally arranged up the slender cane-like stems – hence the common name. The long-lasting inflorescence creates a virtual tower of flowers. The bright yellow flowers poke out from the red bracts, making this an exceptionally showy ginger. The inflorescences are popular as a cut flower, as they can last up to a month in water. The plant is a favourite of hummingbirds.
Costus barbatus will grow in a fairly wide range of light conditions provided that the soil is kept moist during active growth, but prefers partial shade and high humidity. It flowers for nearly all of the year, both from the tops of the stems and from basal stems. It also makes a good pot plant for patios and verandas. It is so easy to grow that it is a great plant for novice gardeners, cool-climate gardeners, lazy gardeners, people looking for a quick-growing garden, and landscape gardeners.
Propagation is from the rhizomes or from cuttings.
The yellow flowers are edible, with a sour lemony flavour. An extract of the stem is used in traditional medicine against gonorrhea, against the common cold, for eye problems, and as a laxative.
