Growing ginger hydroponically offers advantages over other methods of cultivation. The plant needs much less maintenance than if you were to grow it in soil, and relatively little space is necessary for the amount of harvest you will obtain. You must plant ginger from a piece of root (also called a rhizome) with a visible bud. Although for most of its life the plant will not grow in soil, it is helpful to start the plant in compost and move it to a hydroponic system later.
Cut the rhizome into several pieces, ensuring that each has a bud on it. Even if you intend to plant only one ginger plant, it is helpful to attempt to germinate several rhizome sections at once to ensure germination success.
Fill the pot with compost and plant the rhizome pieces about an inch deep into the soil. Water it well and regularly.
Prepare the hydroponic system to receive the ginger plants. Ginger plants require about 1 square foot of growing room each, so ensure that you have a tray or other container with room to keep each plant (if you intend to plant more than one) 12 inches away from the others. The tray should also be between 4 and 6 inches deep.
Check the ginger frequently to see if the rhizomes have germinated. Once several are growing robustly and have produced stems and some leaves, carefully remove the strongest plants (depending on how many plants you want to grow) and rinse off their roots.
Put 2 inches of growing medium into the hydroponic container. Immediately place the ginger plants on top of the growing medium, spreading out the roots. Space plants 12 inches apart. Pour in enough growing medium to cover the roots and keep the plants in place.
Set up your hydroponic system to water and feed the ginger every two hours or so. Use a standard hydroponic nutrient solution to nourish the plants, according to the instructions provided by your hydroponic system manufacturer. Keep the pH of the fluid between 5.5 and 8.0.
Provide your plants with plenty of light, allowing them to rest for at least eight hours out of every 24. Natural sunlight or artificial grow lights will serve this purpose.
After about four months, your plants will have produced rhizomes to their fullest capacity. Harvest the roots, wash and dry them, and store them. Each plant can produce up to 1 lb. of ginger root.