Organic Pest Control

Theresa Rooney
Hennepin County Master Gardener

Mother Nature has a mind of her own…as do the insects and animals, especially when it comes to our own backyard. In general, using a more natural option to control pests lasts longer and only affects the targeted insect or animal. Using stronger chemicals can often kill more than the “bad” bugs and the insect pest population will rebound more quickly than the insect predator population, which can cause a worse problem later on.

Protecting your plants from pests by using barriers like fences or “hiding” the plants by using smelly products and inter-planting, rather than planting all the same kind of plant in one area, is one way of saving your plants. Fences can be used year after year and are very cost effective. These methods can save you money while being gentler on the environment. Use this grid to control any invaders naturally, preserving the environment and your plants!









Ant hills in garden or lawn; garden soil may be moved to build ant hills, ant hills are often indicators of dry or open earth.


Thicken up the lawn. Water your garden well. Use diatomaceous earth and pyrethrins sprays. Caulk entry points. Use “smelly” products to disturb scent trails.




Plant loses vigor and may die. The “sticky” stuff on plant is honeydew and may attract other insects and/or allow fungus or mold to grow.


Use a strong stream of water to wash off insects. Spray with insecticidal soap, lady bug larvae, pyrethrins spray, or hot pepper wax spray.


Box elder Bugs


No damage to plants, but are a nuisance.


Use pyrethrins spray or insecticidal soap on young plants.




Kill songbirds, flatten newly planted plants, and use garden as a litterbox.


Use a “scarecrow” water spray. Put up plant barriers. Plant thorny-type plants. Make loud noises.




Eat, pull out, or nip off buds and plants.

Use fencing, wolf/coyote urine products, “smelly” products like garlic or cloves, hot pepper sprays, blood meal, or “scarecrow” water spray.

Use fencing; wolf/coyote urine products; “smelly” products like garlic/cloves; hot pepper sprays; blood meal; “scarecrow” water spray.




Eat turf grass roots and may attract moles.


Use milky spore, beneficial nematodes, or garlic spray.


Japanese Beetles


Eats both leaves and flowers.


Pick off by hand and toss them into water (soapy or not) in order to drown the beetles. Use milky spore, pyrethrin sprays, and beneficial nematodes.




Dig holes and tunnels in soil, which disturb plant roots and create surface soil mounds.


Use castor oil, garlic, or other “smelly” sprays, or set traps and properly relocate the moles.




Bite and may carry disease.


Use mosquito dunks. Clear away breeding areas and brush areas. Avoid being out at dusk.




Eat or nip off buds, flowers, and plants. May girdle trees.


Use fencing. Use fox urine products, ho pepper sprays, blood meal, or “smelly” products like garlic, clove, or bar soap.




Dig in gardens and eat fruits and vegetables. Damage small trees. May carry disease (bites and in feces).


Use “smelly” sprays or fox or coyote urine products, or “scarecrow” water spray. Put up barriers.




Eat holes in leaves and leave “slime trails.”


Use slug traps, copper barriers, clear back some of the mulch, sluggo (iron phosphate), or diatomaceous earth.




Dig and uproot newly planted plants. Nip off flowers. Eat veggies and fruit.


Mulch over freshly dug soil. Add blood meal. Use “smelly” products like garlic, cloves or cinnamon. Use barriers (fencing on ground and/or over plants). Implement “scarecrow” water sprays. Make water and food available elsewhere.




Dig holes and tunnels in soil. Eat plant roots, and may girdle trees and shrubs.


Cut grasses short in fall. Move wood piles away from house. Encourage hawks and owls. Create barriers and use hot pepper wax sprays.








Bacillus thuringiensis


Can be found at some garden centers, in gardening catalogs, and online gardening sites.


Beneficial Nematodes


Can be found in gardening catalogs.


Diatomaeous Earth


Important! Do not use the DE used for swimming pools. Only use the DE that can be found at garden centers ! May harm your health, so do not breath it in.




For deer use fencing that is tall enough to keep them out. For bunnies, squirrels or raccoons, use only metal/wire fencing where the size of the holes are small enough to keep them out.


Insecticidal Soap


Use only commercial types. Do not make your own from dish detergent. The detergent is a degreaser and may burn your plants.


Milky Spore


Can be found in gardening catalogs.


Predator Urines


Ask your local garden center about which urine is recommended to ward off your particular pest.


Predatory Insects


Made from a member of the Chrysanthemum family and can be found in a powder form to dust your plants with.


Pyrethrin Sprays


Made from a member of the Chrysanthemum family; also found in powder form for use as plant dust.


“Scarecrow” Water Spray


There are many varieties on the market. They can be found online, at gardening centers, and in gardening catalogs.


“Smelly” Products


Includes garlic, cloves, cinnamon, and mint. These interfere with pests finding your vegetables and may also interfere with scent trails laid down by the pests.


Additional notes:

Some insects die or hibernate over winter, so fall clean up may be helpful as early pest prevention.

Limit the use of pesticides to help the “good bugs” become more plentiful.

Encouraging birds into your yard will help eliminate insects.

Always know what pest your garden is experiencing.

Read and follow all instructions for whatever pest remedy product you use.

If you have questions, do not hesitate to ask staff at the place your purchased your product(s).

Read Up

Herb Companion magazine
Ogden Publications, Inc.

Organic Gardening magazine, Rodale, Inc.

Act Locally
Contact the University of Minnesota Extension Services to locate Master Gardeners in your area and call the hotline,, 612-596-2110
Organic Pest Control

Our Sponsors