While it offers many benefits, mulch can also attract termites to your home and other structures. As with everything in home and garden care, the safety or danger of mulch all depends on the materials you use and the way you apply them.
Every year before applying new mulch, make sure you rake away your old mulch or turn it underneath the soil so that you do not end up with a thick build-up of mulch around your foundations.
Woodchip or Bark Mulches
Woodchip or bark mulch attract termites more than other types. Take a few preventative steps to make sure the bugs don't get into your home.
Make sure to keep the mulch several inches from your house and other structures. Be sure that it doesn’t collect on windowsills, decks or steps when you are applying it.
TIP: It is recommended that your mulch remains at least 8 inches away from any wooden surface on your home. Where it is absolutely necessary for mulch to come in contact with your home, make sure that the depth of the mulch does not exceed 2 inches.
Consider using woodchips or bark from trees that are known for their natural insecticide/repellent properties, such as cedar and tea tree.
When buying your mulch, know where it originated. Some market mulches can already be infested with termites (or their larva), and you may unwittingly import the pests into your garden when there wasn’t an issue before.
Other Types of Mulch
If all of these precautions still leave you feeling nervous about some uninvited houseguests, consider using mulch that is not as attractive to termites, such as compost, lawn green waste (leaves, cut grass, etc.) or newspaper.
TIP: It is a common misconception that termites will not infest mulch that is not wooden. All types of mulch keep the ground warm and moist, conditions that certainly appeal to termites, even stone mulch. Regardless of what type of mulch you use, keep the depth of the mulch near your home to a maximum of 2 inches. Any deeper and the ground will never have a chance to dry out. This moisture will attract termites.
There are types of mulch that have been coated in termite poison, typically boric acid. This mulch has been known to work extremely well, but before laying it down it is wise to apply a small test patch in your garden. The boric acid has been known to affect plants in some circumstances.
Barriers and Traps
One smart preventative measure is to apply termite bait traps. These devices are small metal or plastic containers that you half bury in the ground in a perimeter around your house. Inside, you place some bait wood, generally pine, their favorite. If and when you notice termites chewing on the wood, you replace it with poisoned wood, which the termites will then carry back to their hive. When the queen eats the poisoned wood she will die and the hive will disperse.
TIP: If you can, gradually grade the ground around your foundation to slope away from your home. This will offer maximum drainage and eliminate the moist warm environment that attracts termites.
Application and Maintenance
Remember that regardless of the type of mulch you choose, you should always keep it several inches away from your house and other structures to ensure that it will not provide a bridge for any termites to invade your home. It is also important to give only the appropriate amount of water: mulch traps water and heat in the soil, creating a moist warm environment that is perfect for breeding termites.
TIP: Other ways to keep the mulch around your home well-drained is to make sure that your downspouts and gutters are all working properly and that your sprinklers are never aimed at the house.
As long as you research the type of mulch you need and apply it appropriately to your garden, issues with insects will be minimal.
Frequently check your mulch for signs of termites. View some pictures of what a termite hive or infestation would look like. It is also a smart idea to have a professional termite inspection performed yearly.
At the first sign of termites or other pests, immediately have your home treated by a reputable pest control company.