Curcuma--The "Hidden" Ginger
Curcumas are interesting plants, and most of them are easy to grow, once you understand their growing cycle. Curiously, the complaint I hear most often is that the plants go dormant. My opinion is that for several months of the year, you don't have to do anything to maintain them ! Several of the species are widely used as a spice, such as C. domestica and C. longa, also known as Turmeric. Most of the cultivated species and selections have attractive flowers, many of which can be used as cut flowers.One of several orange species used to be popular, but has fallen out of favor for unknown reasons.
There are dozens of species in the genus, from petite species under a foot tall to semi-giant species over 7 feet tall. One of them, C. alismatifolia, has made it to the mass flowering plant market in many areas, erroneously called a "Thai Tulip" . More than a few people think it is indeed a tropical tulip, not a ginger. It has been produced in mass quantities by local So. Florida growers, and shows up for sale in early Summer.
The plants need abundant water and fertilizer combined with bright filtered light to grow their best. When the plants drop their leaves, the plants should be left dry for as long as possible. In containers, this is easy, but in ground beds, many species won't tolerate errant rainfall or irrigation, so a rainproof cover may be needed. The rhizomes will sprout when there is enough heat, usually May or even June in cooler climates. The plants will grow in most parts of the Gulf South, and in all of Florida. They can be grown in containers anywhere that is frost-free in the wintertime, with warmth and sunshine in the summertime. As conservatory or tropical garden-window plants, they lend a great tropical flair in a small area.
The Thai Tulip Ginger
One of the problems faced by collectors is trying to find different species to purchase. There are mail order firms which can ship rhizomes almost anywhere. A comprehensive plant search on eBay or Amazon would like have some good contacts for such plants.
The species and varieties are worth a try in a subtropical garden or in a large window where there is ample light and humidity./ Choose a soil mix suitable for African Violets, mix in a controlled release fertilizer such as Dynamite or Osmocote, and keep the plants well watered. The inflorescences are of rich color and interesting true flowers. The rhizomes of turmeric ginger can be harvested fresh for use in the kitchen. All of these species propagate readily via rhizome divisions, as with most gingers or irises. Propagate them after they have gone dormant, keep the plants dry after the foliage goes dormant, and give them plenty of resources when in active growth. The effort is well rewarded....