Compost Pile Tips: Ant Control

Lots of ants on an old man's hand on a compost pile.

If you have a compost pile, there are times ant control may be an issue. While many new gardeners believe that ants in their compost is a bad thing, experienced gardeners know that ants actually help mix the compost—as long as they don’t over run the pile! Follow this advice to regulate ants in your compost pile.

TIP: Using a closed bin could be what your pile needs to keep the creepy crawlies away. If your pile is enclosed and still experiencing infestation problems, rinse the outside of the bin with soapy water to wash off any enticing smells or ant scent markers. Search for cracks or holes in the bin and patch them up.

Bury Your Food

Ants are like any pests—they’re attracted to food. If you are simply dumping food scraps onto your pile, you’re probably attracting more ants than you need. Mix it up and bury food materials.

TIP: If you are using a compost bin, place sticky traps (double sided tape works well) around the rim of your bin to catch these critters before they enter.

Keep the Heat in

Ants like a cool places, so heat it up. Keep your compost pile hot by covering it with plastic to hold in the heat. Other insects will steer clear too and you’ll avoid infestation if you keep the pile working by turning it regularly and using plastic to hold in the heat.

TIP: Also, including the right ratio of "brown" to "green" elements in your compost pile keeps the compost producing heat. Brown elemets add carbon to the pile and include hay, fall leaves, sawdust, and wood chips. Green elements add nitrogen and include grass clippings, fruit and vegetable scraps, and used coffee grounds. Try and keep a 30:1 brown to green ratio to maintain the highest heat possible.

Keep It Smelling Good

While the natural odor of decomposing matter may smell, it shouldn’t reek. Give your pile a sniff. If it’s not up to snuff, cover the pile with up to 2 inches of manure, dry leaves, bark, eggshells or wood ash. Not only will this give you healthier, more nutrient-rich compost, it will improve the smell and discourage ants.

Keep It Moist, Not Wet or Dry

Compost piles are supposed to be moist, not wet, and not dry. If your pile is dry you’re not mixing it well enough. The soil should be turned every few weeks to ensure that the consistency of the pile is damp to moist, but not wet or soggy. In very hot weather, sprinkle your compost pile with water weekly to keep it moist. Dry compost isn’t decomposing, and wet compost turns away the beneficial creatures, like worms and ants, that you need to help move the compost.

TIP: If ant colonies are forming inside your pile, this is a sign that you are not turning your compost enough. If the pile is being turned regularly, ants cannot build colonies there. Make sure you are turning your pile weekly to discourage infestation.

Things Not to Us

Don’t use orange oil in your compost heap to discourage ants. It will also kill or discourage helpful and necessary worms that turn the compost. And steer clear of pesticides and poisons. Those will remain in the compost and be transferred later to your garden.

TIP: Some inappropriate materials actually attract ants to compost piles. These no-no's include dairy products, fats, oils, meat, and bones. Steer clear!