Dear NRRI Experts,
"Is there a non-chemical or natural way for me to get rid of bugs in my garden and rid my yard of large ant hills?"
A safe, reliable and natural weapon in your arsenal against garden insect pests is diatomaceous earth (DE). Pulverized DE has been used for decades by gardeners with great results. Some versions of powdered DE can be purchased with pyrethrum but the powder alone is safe and effective. DE products can be purchased on line but surprisingly you can find DE locally at a bargain price.
Diatomaceous earth is from the sedimentary remains of diatoms, a group of algae with siliceous (i.e. glass) cell walls that have microscopic pores that give them incredible filtration properties. When crushed and pulverized this results in a powder with microscopically abrasive edges. When an insect contacts this abrasiveness, its exoskeleton becomes scratched, resulting in eventual desiccation. DE is effective on a wide variety of insects and their immature forms, but especially good on ants. DE is not a toxin or chemical, it is an abrasive.
DE can be used in dry form or mixed with water (one to two cups in a gallon of water). Powdered DE can be liberally dusted onto plants or soil surfaces. Since dispensing of powders can be messy, not very precise and sometime irritating (eyes and inhalation), a very effective alternative is to mix one cup of DE into one gallon of water and apply it as a suspension. Water does not reduce the abrasiveness, however heavy rainfall or irrigation does wash DE off plant surfaces. Apply DE directly and liberally to ant hills and note the rate of effectiveness. DE is also very effective on turf insect pests, without harm to pets or humans. It can be used as a spot treatment or general broadcast.
Diatomaceous earth is commonly used as a filtration medium in the maintenance of swimming pools. These types of businesses are your best source of DE at bargain prices. In Duluth, Pools of Fun on Haines Road sells large bags. This grade is finely pulverized and requires some caution relative to irritating particulates, so mixing with water is advisable.