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tomato hornworm damage

Tomato Hornworm Damage: 9 Signs To Look For

Tomato hornworms can destroy your tomato plant’s fruits, foliage, and stems. Before tomato hornworms damage your crops, it’s critical to take action to stop them. To safely grow tomatoes, you need to understand a hornworm’s life cycle and how and when they attack. Keep reading to learn everything you need to know to protect your garden from our team here at A Garden Patch.

If you want to take the hassle out of gardening, try our self-watering tomato planter, which requires no gardening experience and provides water, oxygen, and essential nutrients to grow tomatoes.

1. Green Horned Caterpillars

Hornworms can grow up to four inches in length. You’ve likely dealt with these green caterpillars if you’ve ever grown tomatoes. Besides tomatoes, hornworms devour peppers, eggplants, potatoes, and other plants in the same family.

Hornworms have a green color with a protrusion on their rear that resembles a horn. Their translucent green bodies blend with the color of tomato leaves, providing the perfect camouflage. Sometimes it’s easy to locate hornworms due to their large size; however, their quick appetites can cause significant damage before you can take action.

If you suspect hornworm damage to your tomato plants, consider using a UV (black) light. A hornworm’s body will appear bright green under UV light. A UV light can find hornworms at night since they stay hidden during the day. 

2. Summertime Damage to Your Tomato Plants

Hornworms are active during the summer. Tomato hornworms emerge as adult sphinx moths in the spring. A female lays pearl-like eggs on tomato leaves, and caterpillars usually hatch in one month. As the hornworm matures, it stops eating and burrows underground to become a pupa.

In two weeks, sphinx moths of the second generation emerge and deposit eggs on tomato plants. Hornworms feed until the end of summer, then overwinter in the soil as pupae. This life cycle repeats itself, so we recommend looking for hornworms in the summer. 

3. Presence of Larvae with V-shaped Markings

Start by monitoring hornworm populations in early July to prevent their development in mid-summer. It’s best to scout early in the morning or late at night since larvae tend to hide during the day. Dislodge larvae by shaking part of the tomato plant over cardboard or paper.

Also, consider interplanting dill, marigold, or basil around your tomato plants to keep hornworms away.

4. Chewed and Missing Foliage

Leafless tomato plants are the first sign of hornworm infestations. These oversize caterpillars can cause extensive damage in a short amount of time. During midsummer, hornworms start eating tomato leaves and can continue until harvest.

Hornworms start by attacking the upper portion of the tomato plant, and they can consume entire leaves overnight! A single hornworm can eat as much as four times its weight in leaves and fruit daily.

If you want to stop worrying about pests and critters attacking your tomato plants, get the Garden Patch’s GrowBox. This planter provides perfect plant spacing and nutrient packs to give your plants everything they need to grow, including dolomite for tomatoes.

5. Scarred Tomatoes

Hornworms do not burrow into tomatoes as worms do. Instead, they feed on tomatoes after they have stripped the plant of its leaves and leave telltale damage on the outside of your tomato fruits.

If you notice large, open scars on your tomatoes, you might have a hornworm problem. There is no limit to how many tomatoes hornworms may consume as they feed on ripe and unripe tomatoes. The GrowBox can help you grow healthy tomatoes, and the box allows air to enter the soil to prevent fungus, disease, or root decay. 

6. Decayed Tomatoes

A hornworm infestation can kill your tomatoes. Fruit damaged by hornworms often decays on the vine before harvest. To protect your tomatoes, you should frequently check for exterior damage, like wilted leaves and missing stems.

Growing tomato plants indoors using the GrowBox system will keep hornworms away and stop tomato hornworm damage. The system ensures that the plants are not overwatered to prevent wilting or decaying. 

7. Black Droppings on Leaves

Hornworms blend in amazingly well, but their excrement does not. As hornworms feed, they deposit a distinct kind of manure on the leaves. Dark green or black dropping on tomato plants is another sign that you may have hornworms.

Wear disposable gloves if you notice signs of black droppings. Finding hornworms at their early stages is important to protect your tomato plants. With some practice, you can easily locate hornworms within four to six inches of fresh droppings.

tomato hornworm damage

8. Bigger Droppings Indicate Larger Hornworms 

Bigger hornworms will leave behind large droppings of 1/8th to 1/4th inch in size. The excrement might look like a sphere or pellet.

Fresh droppings appear green in color and indicate that the hornworm is nearby. Pay close attention to the top portions of branches, as hornworms prefer to explore these areas.

Brush off the manure on the leaves after you find the hornworm(s) to make it easier for you to detect new hornworms on your next inspection.

9. Inspect Plants Daily

Daily plant inspections are essential to minimize hornworm damage. Start by looking for common signs of hornworm damage:

  • Visible hornworms
  • Wilted leaves and damaged stems
  • Scars on your tomatoes

Foliage damage indicates that hornworms are lurking somewhere on your tomato plant, and you need to eliminate them immediately.

The GrowBox can help prevent foliage damage by providing everything your tomato plants need to grow successfully. The self-sufficient system makes life easier by automatically feeding and fertilizing your plants. 

Grow Tomatoes with Our Advanced GrowBox System

Are you interested in growing tomatoes without the hassle of digging, fertilizing, or watering? The Garden Patch GrowBox can allow you to grow tomatoes indoors or outdoors. All GrowBox kits include simple instructions, and we can help you learn more about growing tomatoes in the fall.

Contact A Garden Patch today for more information on the GrowBox and how to prevent tomato hornworm damage. Order online or call us at 800-519-1955.

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