Termites eat wood and wood byproducts. Wood byproducts may include fibrous wood mulch that has not yet broken down into the soil. This can include wood-chip mulch and some wooden garden stakes. While there may not be enough wood material to sustain a large colony, the termites may move on to larger fibrous roots. In most cases, termites may not bother living tissue unless the plant is weak from disease.
Remove all wood material that is laying on the ground in the garden site. Cleaning all wooden material is the first step to eliminating any food source for the termites. This may include any and all tree branches and wooden stakes. Ensure that any wood material used for raised garden beds is one that is insect- and rot-resistant.
Replace any wooden support plant stakes with those of red cedar. Red cedar contains a natural oil that most insects, including termites, do not like. Red cedar is also extremely rot-resistant and will last for many years in a garden space.
Cultivate the soil in areas where termites may be present. Termites dislike disturbed soil regardless of the food source that is present. Use both a hand cultivator for areas next to growing plants and a mechanical, powered rototiller for areas between rows. Not only will the cultivated soil aid in disturbing the termites, but it will reduce weeds and loosen the soil as well.
Insert an applicable termite bait into the soil near termite activity. The result will not be immediate as the termites take the food poison bait back to the nest. Generally the bait will take a few weeks to destroy the entire colony.
Apply a termite insecticide to the soil. Follow all label instructions that are provided by the manufacturer.