Plant Gingers and other Root-Hardy Tropicals in Spring

Published 6:30 pm Friday, March 10, 2023

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Perennial flowering plants is one of my favorite garden topics. I like things that can be planted once and relied on to return for a number of years.

Some of the plants that we grow as herbaceous (non-woody) perennials are root-hardy tropical or subtropical plants. Here, the tops die back partially or completely during the winter, and plants regrow from the roots in the spring. Of course, not all tropical plants are root-hardy here, but there are quite a few from which to choose.

While fall is considered the best time to plant most trees, shrubs, and herbaceous perennials of temperate origin, root-hardy tropicals may not survive if they’re planted shortly before cold temperatures arrive. Wait until no more freezes are expected to plant these.

Many gingers are among the root-hardy tropicals that enrich our landscapes in southeastern Louisiana.   

Butterfly ginger (Hedychium coronarium) is one of the more commonly grown and cold-hardy gingers. Plants grow to approximately 4 to 6 feet tall. Flowers are white and fragrant. Butterfly ginger can grow in partial shade or full sun, though leaves may look stressed in full sun. They need a good deal of water and fertilizer for optimal performance.

One of my favorite groups of gingers is the Curcuma genus, which includes the “hidden” and “surprise” lilies, as well as turmeric (C. longa). A spike with colorful bracts emerges either prior to (surprise lilies) or after (hidden lilies) leaves. The name Siam tulip is applied to C. alismatifolia and some Curcuma hybirds. Some of these are root-hardy here, though it’s likely not all are. The hybrid cultivar ‘Laddawan’ has survived for eight years at the Hammond Research Station. C. elata is an especially large root-hardy Curcuma, reaching 6 to 8 feet tall.

While we might choose a Curcuma ginger as a southern substitute for tulips, peacock gingers (Kaempferia spp.) fill a similar landscape niche as hostas. They’re low-growing and grow in shade. Species include K. rotunda and K. pulchra. The former gets larger than the latter.

Other genera that contain one or more root-hardy species of ginger or its relatives include Alpinia, Costus, Globba, and Zingiber.

Let me know if you have questions.

Dr. Mary Helen Ferguson is an Extension Agent with the LSU AgCenter, with horticulture responsibilities in Washington and Tangipahoa Parishes. Contact Mary Helen at mhferguson@agcenter.lsu.edu or 985-277-1850 (Hammond) or 985-839-7855 (Franklinton).