How to Keep Aphids & Worms From a Garden


Discovering aphids and green worms on plants discourages many gardeners. From aphids on spinach, to caterpillars and other worm-like creatures on petunias and other succulent flowers, these pesky critters can ruin a garden if they are not controlled. Early detection and protection are keys to saving your plants. To keep aphids and worms from a garden, spend time with the plants, notice how they are growing and become proactive when the munching insects threaten your garden.


Step 1

Smear a layer of non-toxic ant barrier around the base of the plants. Follow the package instructions for application details. Placing ant stakes around the plants is another option, but they contain a chemical pesticide.

Step 2

Place sticky traps specifically made for aphids in the soil around affected plants.

Step 3

Spray infested plants with insecticidal soap if other methods of controlling aphids fail. Spray the plants after sundown and repeat every other day until you see a significant reduction in the number of aphids.

Step 4

Introduce ladybugs to the garden. They love to eat aphids.


Step 1

Look for caterpillar and other worm droppings on your plants and on the soil below them if you begin to see holes in the leaves of your plants or on fruit such as tomatoes. These creatures eat the green leaves of your plants, so they can be hard to spot because they become the same color as your plant's leaves. Looking for their small black pellet-like droppings is a good way to find them, because they will usually be just above the area where their droppings land.

Step 2

Hand-pick worms and kill them by stepping on them or squashing them. Where one worm lives, chances are there will be others, so keep up your hunting and killing throughout the growing season.

Step 3

Spray a powder of Bacillus thuringiensis on affected plants. This product, also called Bt, is a natural soil bacterium toxic to wormy pests. It can also be helpful against the larvae of some beetles and fly larvae. It is more effective against young, small wormy pests than larger ones, such as adult tomato hornworms. Repeat your application weekly if you continue to see the problem caterpillar or worm.

Tips and Warnings

  • Always follow label instructions closely when using chemicals in the garden. Correctly identify your insect pests because many beneficial insects will populate a garden and are attracted to insects such as aphids.

Things You'll Need

  • Non-toxic ant barrier
  • Ant stakes
  • Aphid trap kit
  • Insecticidal soap
  • Spray bottle
  • Bt powder


  • Tanglefoot Products: Aphid traps
  • Tanglefoot Products: Adhesive Pest Management
  • Colorado State University Extension: Bacillus thuringiensis
Keywords: pest control, aphids worms, caterpillars Bt

About this Author

Barbara Fahs lives on Hawaii island, where she has created Hiā€˜iaka's Healing Herb Garden. Barbara 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 She earned her B.A. at UCSB and her M.A. from San Jose State University.