There are many species of ginger. Ginger lilies, for example, make beautiful ornamental plants. The kahili ginger, can reach up to 8 feet in height and produce beautiful cascading flower clusters that can reach the size of a loaf of bread. But once ginger is introduced into your garden, it can quickly become an invasive menace. Aggressive species like wild ginger, red ginger or the kahili ginger lily grow quickly and will choke out nearby plants if not killed.
Cut the ginger plants back to a few inches in height using a sharp pair of pruning or lopping shears. Gather up the cut stems, cut them into 1 inch pieces and compost them.
Water the planting area so that it is quite moist to a depth of 4 to 5 inches. This will loosen the soil and make removing the ginger roots easier.
Dig up each of the ginger bulbs. Use a trowel to dig in a 3-inch radius around the cut stalk of the ginger plant. Then grab the stalk of the ginger plant and pull the entire root up. If the stalk is stubborn, use your trowel to dig a little deeper while pushing the stalk back and forth to loosen the soil.
Check the soil. Any overlooked pieces of ginger root will likely germinate to form new ginger plants. Use your trowel to dig around the soil up to the depth of the ginger root you uprooted. Remove any leftover pieces of ginger root, no matter how small, and compost them.
Spray the ginger plants with an herbicide between spring and late autumn if you do not want to dig them up. Use an herbicide prescribed for use on tubers like Meturon Knapsack and a penetrant like Pulse. Mix the herbicide with water, following the manufacturer's instructions (Meturon should be mixed at a rate of 5g per 10 liters of water) and then add the penetrant (Pulse should be added at 100ml per 10 liters of herbicide/water mixture). Then cut the ginger's foliage back to 2 inches in height. Remove the dirt around the plant until you expose the tuber. Then spray the tubers and the plant tissue with the herbicide mixture until they are wet but not dripping wet. The ginger root will dry out and die in three to four months.