Curcumas thrive in tropical summer conditions

Over a month ago I was gifted an exotic curcuma with two beautiful flower stalks. The tag said to give it full sun and keep it moist, so I placed it in an area that gets late afternoon sun and I added water every other day. This showy tropical plant has continued to thrive, producing new growth and new flower stalks, making it my new favorite plant.

This new plant is Curcuma alimatifolia "Siam Shadow," one of several releases in the Shades of Summer series. Also called tulip gingers, these plants mature at 18 inches tall, are native to Thailand, and were bred and owned by K.P. Holland. Although they are listed for zones 10 and 11, according to Tom Wood, ginger breeder and grower, these plants are reliable at surviving winters in landscape beds in zones 8 and 9.

Curcuma is a group of plants in the ginger family (Zingiberaceae) called hidden or surprise gingers. Some curcuma produce flowers that are on low flower stalks covered up by their lush foliage, hence the name hidden ginger. Plants range in size from one to more than eight feet tall and leaves are broad, similar in shape to canna lilies. Leaves are sometimes pleated or have colorful markings, so they create interesting texture and color even when plants are not in bloom.

Flowers are colorful cone-like structures that are sometimes atop tall terminal spikes, while others are low to the ground. As with many gingers, these make great cut flowers and are frequently used in floral arrangements. What most people consider as flowers are actually colorful leaves referred to as bracts. If you look closely, the flowers are tucked away inside at the base of the lower bracts. The "Siam Shadow" has beautiful purple-pink bracts with a deeper tone at the tips and the actual flowers are blue-purple in color. Leaves have a faint burgundy stripe down the center midrib.

Like other curcumas, they can be grown in a container or in the landscape in either full sun or partial shade. Check the species and variety because some prefer more shade than others. They prefer a well-drained rich organic soil and can be mixed in with other heat-loving plants like bananas, blue salvia or hibiscus. Curcumas like to be on the dry side during the winter months and moist during the growing season. If soils dry out during summer months, leaves will turn an unattractive brown and plants will stop producing flowers. Keeping soil moist is especially important if plants are growing in full sun.

Most curcumas are perennials in our area, but the foliage will turn yellow in the fall. This is natural, so just prune off the yellow leaves and the plant will rest until next spring. Apply a layer of an organic mulch to protect the rhizomes during the winter months. Once soils heat up in April or May, leaves will emerge from underground rhizomes. The best time to fertilize these plants is in early spring and again in summer to promote new growth. Use a slow-release fertilizer that includes micronutrients. As with other ginger-type plants, expect them the spread, so give them plenty of room. Periodically, plants may need to be divided for best performance.

You might look for other popular members of this group. One that is very attractive because of the amazing red stems is "Scarlet Fever." This one can reach six feet in height and produces cones with pink bracts with yellow flowers. Even if this one isn’t in bloom, it’s a great landscape plant. One that is a little shorter in stature topping out at around three feet tall is Curcuma petiolata, which sports large cones with pink bracts and yellow flowers. If you want variegated foliage, look for Curcuma "Emperor" with a creamy white edge or "Snowdrift," which has even more variegation.

Another variety that might be of interest to many is turmeric, Curcuma longa. Turmeric is popular in Indian cooking and is an ingredient in curry. This plant grows well in Florida landscapes, allowing you to harvest your own rhizomes. Plants reach around three feet in height and flowers are yellow with white bracts. Grow them in partial to full shade and harvest the rhizomes as plants die back in late fall to winter. For more information on growing and using turmeric, go to http://gardeningsolutions.ifas.ufl.edu/plants/edibles/vegetables/turmeric.html.

If you are interested in adding a tropical look to your landscape, add curcuma to your shopping list. Based on my experience, this plant will become one of your favorites too.

Terry Brite DelValle is a horticulture extension agent with the Duval County Extension Service and the University of Florida/IFAS.