Ginger (Zingiber officinale) is a tropical plant that naturally thrives in warm, humid climates and is extremely sensitive to cold temperatures, especially frost. As a rhizome-producing perennial, it will not survive the winter outdoors in most temperate regions, as temperatures below 40°F (5°C) can cause the plant to die. Successfully preserving ginger requires a deliberate strategy: either forcing the entire plant into a cool, dormant state or harvesting the underground rhizomes for separate storage. This intervention ensures the viability of the plant or the harvest for the following growing season.
Overwintering the Dormant Potted Plant
Keeping a ginger plant alive but inactive over the winter is an effective method for ensuring its return in the spring. The first step is to wait for the natural seasonal signal, which is the dieback of the above-ground foliage. As temperatures cool, the leafy stems will begin to yellow and eventually dry out, signaling the plant is entering its natural dormancy period.
Once the foliage has completely died back, the stems should be cut down to just above the soil level. The potted rhizome can then be moved indoors to an appropriate location for its winter rest. The ideal conditions for dormancy are cool and dry, with the temperature consistently maintained above 50°F (10°C).
During this dormant phase, the plant requires only minimal care to prevent the rhizome from completely desiccating. The goal is to keep the potting medium barely moist, not wet, which means watering only very sparingly, perhaps once per month. Overwatering during dormancy is a common mistake and can quickly lead to rhizome rot. The pot should be stored away from any direct heat sources, such as radiators, which can dry out the surrounding air and soil too quickly.
Harvesting and Curing Rhizomes
For those who prefer to harvest the rhizomes rather than overwinter the entire plant, timing the harvest is crucial for maximum maturity and flavor. The best time to harvest mature ginger is typically 8 to 10 months after planting, when the plant’s leafy stems have fully yellowed and dried out. This natural dieback indicates that the plant has directed its energy and nutrients into the rhizomes underground.
The harvesting process should be done carefully to avoid damaging the rhizomes, often by gently loosening the soil with a garden fork before lifting the entire plant. Once lifted, excess soil should be shaken off the rhizomes; however, the ginger should not be thoroughly washed with water at this stage. Instead, use a soft brush or cloth to clean off any remaining dirt, as washing can introduce moisture that promotes mold and decay during storage.
After cleaning, the rhizomes must go through a short but important process called curing. Curing involves letting the harvested ginger dry for several days in a warm, dry location with good air circulation. This period allows the skin to harden and any minor cuts or nicks to form a protective callus. This callus is a necessary barrier against pathogens and excessive moisture loss during long-term storage. The stems and any small, fine roots should be trimmed off before the curing begins.
Long-Term Storage Methods
Once the ginger rhizomes are fully cured, they can be prepared for various long-term storage methods depending on whether they are intended for replanting or culinary use.
Storing Seed Ginger
For storing seed ginger intended for replanting, the goal is to keep the rhizomes dormant and firm until spring. Layer the cured rhizomes in a breathable medium such as peat moss, sawdust, or dry sand. This storage medium should be placed in a container and kept in a dark, cool environment, ideally with a temperature range between 40°F and 50°F (4°C and 10°C). The medium should be kept barely moist to prevent the rhizomes from shriveling, but not wet, which would cause them to rot. This cool, slightly humid environment minimizes shrinkage while preserving the rhizomes’ ability to sprout.
Storing Culinary Ginger
For rhizomes intended for cooking, a simpler approach often suffices, such as storing them in a paper bag or a loosely covered container in a cool pantry or basement. The ideal storage conditions for culinary ginger are temperatures around 55°F (13°C) and a relative humidity between 65 to 75 percent. For immediate and longer-term convenience, freezing is an excellent option. The whole or portioned rhizomes can be sealed in an airtight bag or container and stored in a freezer, where they will maintain their flavor and texture for many months.