Termites attacking a live palm tree (Arecaceae) will eat it from the inside out, often starting at the roots and working their way up. Act quickly at the first sight of termites or telltale mud mounds to salvage the palm tree. Start by removing and burning any branches that seem dead or hollow and raking mulch away from the base of the trunk. Then, choose your counterattack: nematodes, homemade sprays or a professionally applied termiticide.
Release Natural Predators
Nematodes are microscopic roundworms that eat termites and many other pests. The nematode species used typically include Heterorhabditis bacteriophora, Steinernema carpocapsae, and Steinernema feltiae. These aren't the same roundworm species that infect people or pets, so they're a completely safe option for your family and for the environment. Best of all, nematodes can kill a termite colony within three months.
Nematodes must be kept refrigerated until use, or they'll die. To ensure they arrive live and well, select an appropriate shipping option if ordering online. They're packaged inside a spongelike material. Soak the sponges in a bucket of warm water and wring the water out into the bucket to transfer the nematodes to the water.
Spray the soil around the palm tree with water from the hose. Pour the nematode water onto the wet soil. Early morning or late afternoon is the best time to do this, because the water may evaporate too quickly in midday heat and because nematodes are light-sensitive.
Other Natural Solutions
Other natural remedies exist for killing termites, but they're ineffective against a large colony attacking a palm tree. That's because the remedies are topical solutions that work only when they come into direct contact with termites. Termites are very sensitive to sunlight and prefer to stay hidden underground or inside the tree where they build vast networks of tunnels. They're unlikely to come aboveground and into contact with the lethal substance.
However, these topical remedies may suffice in protecting the tree from termite scouts, which are easy to recognize because they have wings. These termites are looking for a new food source for the colony. Killing them as soon as possible could prevent a full-blown infestation.
One option is to mix 1/2 cup of distilled white vinegar with 1/3 cup of fresh lemon juice in a spray bottle and spray the solution directly onto termites or anywhere termites are suspected. Another option involves sprinkling borax powder around the palm tree, or mixing it with water in a spray bottle to spray it directly on the trunk or branches. An orange oil spray will also kill termites on contact.
Termiticides: Last Resort
If you decide that the infestation requires a termiticide (a pesticide that specifically targets termites), call a professional to ensure that the health and environmental effects of these toxic chemicals are properly mitigated. The active ingredients in termiticides can cause irritation of the skin, lungs and more. Some, such as imidacloprid, last for years in the soil, whereas others, like fipronil, break down relatively quickly.
Choose a reputable and licensed company and ask plenty of questions about the termiticides they use and how these will affect your live palm tree and the environment in general.