Special Research Report #509: Production Technology

Ornamental as Flowering Potted – Part 1 General Aspects Jeff S. Kuehny, Depart. of Horticulture, Louisiana State University, Baton Rouge, 70803-2120 Richard A. Criley, Depart. Tropical & Soil Sciences, University of Hawaii, Honolulu, 96822-2279 perennials (USDA Zone 8 - held in dry storage for 11) or summer annuals in approximately 3 months. exterior landscapes Gingers can also be depending upon the climate. purchased in plug trays from The most common genera tissue culture companies. used for these purposes However, the Kaempferia FUNDING INDUSTRY SOLUTIONS include: , Globba, species are the only ones TODAY & TOMORROW Hedychium, Kaempferia, and recommended for growing Phone: 618/692-0045 Fax: 618/692-4045 Siphonochilus. from a tissue cultured plug, if E-mail: [email protected] a finished plant is desired in a Website: www.endowment.org Most gingers are 60 day period. Those gingers herbaceous perennials with grown as flowering potted BACKGROUND aromatic, short, thickened (or plants (see Table 1) flower Ornamental gingers long, thin) rhizomes. Some more quickly and uniformly ( family) are a rhizomes, e.g., Curcuma and when grown from rhizomes. diverse and versatile group of Globba, have tuberous If tissue-cultured plants are plants. They are increasing in storage vessels attached by a purchased, a fuller plant can usage as flowering potted modified underground stem be grown if plants are plants, landscaping, and fresh that have been termed “t- allowed to go dormant in the cut flowers. The various roots” or “milk sacs”. fall by withholding water as heights, flower colors, and the days became shorter and postproduction longevity (up temperatures become cooler. to four weeks or longer) of Many growers then remove these tropical and subtropical the dead foliage and force the plants brings diversity to the rhizomes in the same floriculture industry. containers the next spring, Characteristics that make i.e., after February. them attractive as flowering potted plants are: (1) the ease As with most bulbous and of production in the shade tuberous crops, the media house or greenhouse; (2) must have excellent drainage unique foliage; (3) and water holding capacity. production of many The soils of the native habitat flowering stems per pot; (4) of gingers have a slightly long-lasting colorful bracts; acidic to neutral pH. Thus, (5) a 90 to 100 day dolomitic limestone should production cycle; and (6) few be added to the medium to disease or insect problems. Underground storage organ provide a pH of In addition to being used as of C. alismatifolia. approximately 6 to 7. A potted plants, they can be “standard” depth container or Many of these gingers are marketed not only for use in a deeper pot must be used. It produced in Thailand. The year-around interior will not only provide rhizomes are harvested from landscapes but also as either drainage but also provide November to December and space for placing the tuberous rhizomes. The grading Some ginger are boron roots attached to the rhizome system is usually based on accumulators, which may toward the bottom of the pot the number of tuberous roots lead to marginal necrosis. while allowing the covering per rhizome. After the initial Therefore, plants should be of the rhizome with irrigation, plants should be fertilized with a water soluble approximately one inch of given a preventative fertilizer low in boron or media. Breaking the fungicide treatment. without boron. Other cultural tuberous roots from the requirements are provided in rhizome it not advised. It Greenhouse temperatures Table 1. may decrease flowering and should be kept at 85 to 90oF delay time to emergence. until emergence of shoots. For additional information Thus, care must be taken to This helps to promote a more contact Jeff Kuehny at keep the entire tuberous root uniform plant emergence. [email protected]. intact. Two or three, two year old rhizomes planted in After emergence, greenhouse 2003 November © Copyright a six inch pot will produce a temperatures should be The American Floral marketable finished plant. lowered to less than 85oF. Endowment. All Rights Some companies grade the Reserved

Table 1. Species information on the most popular ornamental gingers. Species Average Inflorescence and Foliage Plant Height Cornukaempferia 1 foot Leaves with silver feathered margins to dark maroon centers, aurantiflora small orange flowers. 40 to 60% shade. Curcuma alismatifolia 2 feet Tulip shaped flowers, ~ 3 - 4", pink or white. PGR required. Full sun. Curcuma cordata 2 - 3 feet Cone shaped flowers, ~ 4 to 6", pink. PGR required. Full sun to 50% shade. Curcuma roscoeana 2 - 3 feet Cone shaped flowers, ~ 4 - 5", bright orange. PGR required. 40 to 60% shade. Curcuma sp. ‘Precious 1 foot Tulip shaped flowers, ~ 1 - 2", pink, pink w/green tips. Full Patuma’ sun. No PGR required.. Curcuma petiolata 2 to 3 feet Grown for variegated foliage. Full sun to 50% shade. No ‘Emperor’ PGR required.

Curcuma thorellii 1 foot Tulip shaped flowers, ~ 2 - 3", pure white. Grown from ‘Chiang Mai Snow’ rhizome. No PGR required. Globba spp. 1 to 2 feet Arching pendulate flower stalks with white, pink, dark purple, or yellow bracts. Grow from rhizome. ‘White Dragon’ requires a PGR drench. 40 to 60% shade. Kaempferia spp. 1 to 3 feet Grown primarily for foliage. Can be grown from tissue culture or rhizome. 40 to 60% shade. No PGR. Siphonochilus spp. 2 to 3 feet Flowers borne on spike, yellow or pink. Grow from rhizome. 40 to 60% shade. PGR may be required.