The increasing availability of gingers in rhizome form has many people opting for this often less expensive way to build their collection. Gingers that have natural dormancies are often produced and sold by wholesalers in this dormant state. For the retailers and collectors rhizomes are often the preferred method of sending plants. Rhizomes can store for long periods, they weigh less than growing plants, and the receiver need not plant them immediately. For people buying rhizomes, it is often a less expensive option. Those selling rhizomes often pass on the savings to customers, preferring to move more rhizomes at a lower cost than having to pack and process plants. Rhizomes can be sent at any point during their dormancy, though one should make sure they aren’t exposed to any temperature extremes during transit. Many retailers that have no experience growing gingers from rhizomes are now carrying these new exotics and unfortunately are passing along bad information with the rhizomes. This article should explain how to improve your success with rhizomes, and point out some important information that most people are unaware of.
To start, we need to make a distinction between rhizomes of naturally deciduous gingers, and those of evergreen species. Rhizomes of evergreen species often do not store well. Some retailers offer rhizomes of evergreens and suggest that they can be treated the same as the deciduous species, this is unfortunately not a good practice at all. Rhizomes of evergreen species are best bought close to spring time so the can be planted immediately. To learn more about which gingers are natural deciduous and which are evergreen please read the article on this topic on the articles page. The rhizomes that this article focuses on are those of naturally deciduous gingers such as Curcuma and Kaempferia.
For those obtaining rhizomes for the first time a few things must be kept in mind. One very common question people have AFTER they have planted rhizomes is “I planted these things two weeks ago, why haven’t they sprouted?” What so many people that sell rhizomes either don’t know, or fail to tell their customers is that gingers do not automatically sprout once planted. In the wild these gingers are exposed to 3 seasons: The rainy season, the dry season, and a very hot dry season just before the rains return. It is this hot season that stimulates gingers to sprout. The soil temperatures rises and this makes the rhizomes break dormancy. By the time they sprout the rainy season has begun. Those living in the south expect their gingers to sprout when other bulbs and perennials have begun sprouting, but gingers are often the very last plants to return. Even in the ground, gingers take a long time to sprout because the soil temperature is still not warm enough in early spring. It is a fact of life that people must deal with, but its well worth the wait to have these plants thriving in the heat of summer when everything else looks terrible! Patience is very important when growing gingers from rhizomes. The counter does not start until the soil temperature is high enough, regardless of planting date.
Ginger rhizomes should be planted shallow, with about a ½ an inch of soil covering the rhizomes. It doesn’t serve much purpose to plant rhizomes in the middle of winter, so they should be planted or potted definitely after the last freeze date. If growing in pots, the soil should only be kept slightly moist until the rhizomes have sprouted. Rhizomes can be planted directly into the garden, but it is often easier to start them in pots. For those unfamiliar with ginger rhizomes, and their parts, one important feature must be recognized.
Gardeners often want the most for their money and are tempted to separate ginger rhizomes before they are planted. It is best to divide them AFTER they begin to sprout. More importantly, many often mistake storage tubers and fattened storage roots as additional growing parts and break these off!! These storage parts are what makes gingers sprout so fast and removing them can seriously damage the plant. What would have been a beautiful blooming ‘Tulip Ginger’ can be reduced to a few weak leaves and no blooms by doing this.
Another frequently asked question regarding rhizomes is “Which side is up?” This is hard to explain in text, so please look at the included photos for planting instructions.
For those who already grow gingers but want to store rhizomes, the question of how best to store their rhizomes is often asked. For those wishing to divide rhizomes to share, I recommend multiplying the plants during the growing season and just lifting the new divisions once they go dormant. One can divide dormant rhizomes, but this often can lead to rot or the rhizomes drying up too much. Just lifting a plant, washing, and drying it so much easier and safer. Rhizomes should be kept in a cool dry place for the dormant period. Some air movement is necessary to prevent mold from sprouting. In addition, rhizomes should not be stored directly on top of plastic or other surfaces. The addition of paper towels, shavings, or anything else to prevent the rhizomes from “sweating” on top of a flat surface will prevent moisture from building up underneath the rhizomes, causing rot.
Horticulture researchers in both Thailand and the US have been experimenting with forcing ginger rhizomes into breaking dormancy early. Some of this information may end up being useful for the average gardener and will be incorporated into future updates of this article.