Tomato Worms

Featured, Garden Maintenance, Pest Control

Tomato worms, especially the tomato hornworm, are among the most notorious pests in home vegetable gardens. Their voracious appetite and stealthy camouflage can wipe out tomato plants almost overnight. Here’s how to identify, manage, and eliminate them in your Canadian garden.

🐛 What Are Tomato Worms?

“Tomato worm” typically refers to the tomato hornworm, the larval stage of the five-spotted hawk moth. These caterpillars are:

Green with white stripes and a signature curved “horn” on the rear.
Large, growing up to 4 inches long.
Camouflaged among tomato foliage.
Found on tomatoes, eggplants, peppers, and potatoes (all nightshades).

🌿 Why Do You Get Tomato Worms?

Tomato hornworms are native to North America and lay their eggs on nightshade family plants. You might get an infestation due to:

Warm summer temperatures encouraging moth activity.
Lack of natural predators, such as birds or parasitic wasps.
Monoculture planting, which makes it easier for pests to find their preferred food.

🔍 Signs of Infestation

Skeletonized leaves with only veins remaining.
Dark green or black droppings (frass) on lower leaves.
Missing stems and stripped branches.
The worms themselves—hard to see but often on the undersides of leaves.

✅ 4 Ways to Get Rid of Tomato Worms

1. Handpicking (Organic & Effective)

Inspect plants daily.
Remove worms and drop them into a bucket of soapy water.
Use gloves if you prefer not to touch them directly.

2. Encourage Natural Predators

Attract beneficial insects like braconid wasps, which lay eggs on the worms.
Leave hornworms with white egg sacs alone—they’re parasitized.
Plant flowers like dill, fennel, and yarrow to attract predatory insects.

3. Use Biological Controls (BT Spray)

Apply Bacillus thuringiensis (BT), a bacteria that targets caterpillars.
Safe for humans, pets, and pollinators.
Reapply after rain or heavy watering.

4. Companion Planting

Plant basil, marigold, or borage near tomatoes to help repel hornworms.
These also attract beneficial insects.

🗓️ Tomato Worm Prevention Calendar

Task	Timeline
Start checking for eggs	Late May to June
Daily plant inspection	June through August
Apply BT if needed	July to August
Remove infested plants	Late summer if needed