x
 
 
Learn which plants thrive in your Hardiness Zone with our new interactive map!

How to Get Bugs to Stop Eating Outdoor Plants

By Barbara Fahs ; Updated September 21, 2017

After you have put a lot of elbow grease and love into planting and growing a plant, it’s disheartening to find that insects have made it their dinner before you have a chance to eat it or enjoy looking at it. Any plant can be subject to an insect attack, and many different types of insects can attack your vegetables, roses, fruit trees, lawn and any other plants you cherish. The most common insects include aphids, spider mites, mealy bugs, scales, worms and caterpillars. You can help control insects by spraying or dusting your plants with natural products, but it's virtually impossible to completely eliminate all insects.

Soft-Bodied Insects

Watch for ants on your plants: they can be the first indication that a plant is under attack by aphids. Ants “farm” these insects, and some others, and feed on a sweet excretion called honeydew that the ants produce. Spider mites and mealy bugs are also good subjects for this type of control.

Blast your plant with a sharp stream of water, which will knock many invading insects off the plant and onto the ground.

Mix a solution of liquid dish soap with water (Ivory liquid is recommended). Place 1 tablespoon of soap into a 24 or 32-ounce spray bottle and fill it with water. Or purchase commercial insecticidal soap. To make an extra effective spray, add some crushed garlic and/or hot pepper sauce (for example, Tabasco sauce) to your soap spray.

Armored Insects

Look for ants on your plants because scale insects also feed off their sweet excretion.

Spray plants with your soap spray or insecticidal soap when scale insects are in their soft-shelled “crawler” stage.

Mix one tablespoon of canola oil with your 24- or 32-ounce spray bottle containing your soap spray or insecticidal soap when scale insects are in their mature armored stage. The oil will smother them and the soap will kill any juveniles that can be difficult to see. Hand-pick these insects and discard them.

Worms & Caterpillars

Identify the type of worm or caterpillar that is eating your plant because some caterpillars can be the larval stage of butterflies such as the monarch (see “Tips”). It’s best to begin your control of worms and caterpillars when they are small.

Hand pick and discard as many worms or caterpillars as you can find.

Apply a dusting of Bacillus thuringiensis (Bt), available at garden centers, onto your plant if the invasion is widespread.

 

Things You Will Need

  • Garden hose with adjustable spray head
  • Liquid dish soap or insecticidal soap
  • Garlic or hot pepper
  • Canola oil
  • Bacillus thuringiensis

Tips

  • Earthworms, which live under the soil surface, are completely beneficial, so if you see any of these creatures, be sure not to kill them.
  • If you identify any caterpillars as the larvae of desirable butterflies, you can trap them and release them in a natural setting.
  • Some insects are beneficial because they eat other insects. For example, the lady bug likes to dine on aphids. If you can identify the insect that is eating your plant, do some research on the types of other insects that eat them or parasitize them. Many of these insects are available for sale.
  • Snails and slugs are not insects, but rather, mollusks. They cause serious damage to gardens, especially young plants. Control them by sprinkling diatomaceous earth around your garden bed. A natural product called iron phosphate granules, available commercially under such names as "Sluggo," is also effective. Also, hand pick as many of these creatures as you can find when they are active at night.

Warning

  • Follow label instructions closely whenever you use any insect control products, even if they are dubbed "natural" or "organic."

About the Author

 

Barbara Fahs lives on Hawaii island, where she has created Hi'iaka's Healing Herb Garden. Fahs wrote "Super Simple Guide to Creating Hawaiian Gardens" and has been a professional writer since 1984. She contributes to "Big Island Weekly," "Ke Ola" magazine and various websites. She earned her Bachelor of Arts at University of California, Santa Barbara and her Master of Arts from San Jose State University.