Tomato gardeners often find their prized plants under attack from a variety of pests, both during the day and at night. While some insects like hornworms and aphids are easily identifiable, others leave only signs of their presence, like chewed leaves or half-eaten fruits. Protecting your tomato crop requires being able to identify the animals and insects that pose a threat while understanding their habits and behaviors. In this post, well explore the common nocturnal pests that target tomato plants and the evidence they leave behind, so you can have good luck identifying them. We will also provide practical strategies to safeguard your tomato harvest from these hungry invaders.
What’s Eating My Tomato Plant Stems? How to Identify and Stop These 6 Common Tomato Pests
As a home gardener few things are more frustrating than walking out to your vegetable patch and finding entire stems of your prized tomato plants chewed through or missing leaves and fruit. While you were eagerly watching your tomatoes ripen some nefarious critter was making an all-you-can-eat salad bar out of your harvest!
But before you resign yourself to a summer without homegrown tomatoes take heart. There are ways to identify what’s attacking your plants and protect them from further damage. Here are six of the most common tomato pests that may be chewing on your plants’ stems and how to stop them.
Cutworms
The number one suspect when it comes to tomato stems being eaten or cut through is usually cutworms. These plump, inch-long caterpillar-like larvae come out at night to chew through seedling stems or the stems of established plants. They then hide underground during the day. The first sign is often waking up to find newly planted tomatoes flopped over on the ground with a clean cut chewed right through the stem. Or you may find established plants with whole branches wilted or dead because their stems were eaten through under cover of darkness.
The good news is that cutworms are easy to control with preventative measures. Place a 3-4 inch collar of cardboard around transplants when you first plant them. Or encircle stems with aluminum foil or metal cans with both ends removed. Diatomaceous earth sprinkled around the base of plants can also deter cutworms. Finding and destroying them around plants is key. Check under debris near damaged plants and crush any you find.
Tomato Hornworms
While cutworms nibble stems from underneath soil level, tomato hornworms aggressively munch foliage and damage above-ground parts of tomato plants. These huge green caterpillars have white v-shaped marks and a prominent horn on their rear end. They can quickly defoliate and even kill tomato plants if left unchecked. Besides leaves, they will also sometimes chew on upper stems.
Carefully check the upper parts of plants for hornworms daily during summer months. Look under leaves and on top of soil around plants. Pick off any you find and squish or drop in soapy water. Using Bt (Bacillus thuringiensis) is also very effective against these voracious pests. It’s safe for humans and beneficial insects but kills hornworms when they ingest it.
Click Beetle Larvae
While the adult click beetles are not plant pests, their wireworm larvae can do significant damage to tomato plants, including stem chewing. Click beetle greyish-brown larvae live underground and feed on seeds, roots, and stems. Damaged plants may become stunted or wilt. Inspection of damaged roots and under the soil near plants may reveal click beetle larvae.
There are few chemical control options for wireworms. Practicing crop rotation is one of the best preventative measures. Avoid planting nightshade vegetables like tomatoes, potatoes, peppers or eggplant in the same spot year to year. Using plastic mulch instead of bare soil can also prevent access. Diatomaceous earth around plants may provide some protection.
Stem Boring Insects
A variety of insects are referred to as “stem borers” because their larvae bore into and tunnel inside of plant stems as they feed. This damages vascular tissues and interrupts the plant’s ability to transport water and nutrients. Fully grown larvae then chew their way out, leaving behind significant destruction. In tomatoes, corn earworms are a common stem borer. You may notice sawdust-like frass around damaged stem areas.
It’s difficult to combat borers once they are inside stems, so prevention is critical. Be on the lookout for small holes in stems and any evidence of frass. Handpicking larger caterpillars is possible. Using row covers early on can exclude moths who lay eggs. Beneficial nematodes applied to soil kill larvae. Bt is also effective when sprayed on vulnerable stem areas where entry commonly occurs.
Flea Beetles
Tiny black flea beetles are notorious for chewing tiny holes in tomato plant leaves, but they don’t stop there. These small jumping beetles will also chew pits and wounds in tender stems if foliage is depleted. Heavily damaged plants become weakened and may wilt or suffer dieback. Flea beetles are especially problematic for young transplants.
Row covers are the best defense against flea beetles, excluding them from plants entirely. Diatomaceous earth around the base of plants also deters the beetles. Traps using yellow bowls of soapy water can catch some adults. Insecticidal soaps and neem oil sprays are also useful once beetles are detected on plants.
Rodents and Birds
Hungry rodents like rabbits, groundhogs, rats, and mice are all potential tomato stem chewers. Larger animals like deer may also nibble. Squirrels and birds can also sometimes damage tender upper stems and branches. Identifying these culprits means looking for other tell-tale signs like paw prints, droppings, or bite marks. Deer repellents using rotten eggs, hot peppers, or strong scents can be sprayed around vulnerable garden areas. Fencing and netting provide the best protection from hungry mammals. Scarecrows, reflective tape, and noisemakers may help deter birds. A garden cat is also a great way to scare off small rodents!
By identifying what pest is targeting your tomato plants’ stems and taking appropriate counter-measures, you can still enjoy a bountiful tomato harvest. Consistent monitoring, prevention tactics, and quick interventions when pests appear will keep your plants healthy and happy despite these common tomato nibblers. A little effort goes a long way when it comes to growing luscious tomatoes. Don’t let a few chewed stems stop you from succeeding!
Physical Barriers are a Good Way to protect Homegrown Tomatoes from the Common Culprit
Protective netting is a great way to fortify tomato harvests! Having a fence around your tomato plants can safeguard your whole homegrown harvest, whether youre battling pests during the day or at night. Protective fencing specifically designed for gardening can block out most ground pests while allowing sunlight, air, and water to reach the plants. It can be important to not use too fine of a mesh, because you still want pollinators visiting your garden! And youll need to regularly inspect your fencing to make sure no pests have breached your defenses.
Expert Advice from Tomato Growers for the Best Thing in Pest Control
There are many different types of tomatoes. When first deciding to plant a tomato garden, be sure to do the research and select a disease-resistant variety for your local area. When planting, maintain a generous spacing between plants for better air circulation. Choose good companion plants for tomatoes like basil, marigolds, and mint, which can also help deter some pests. Prepare your soil properly. Be sure to give your plants enough water, but over-watering is also an issue and can drown your plants.
Consistently monitor for pestilence and disease. Early intervention is the key to giving your plants a fighting chance to thrive.
Master gardeners emphasize an integrated, synergistic approach to pest control, combining multiple methods that work together for a better outcome. Stopping pests should go beyond physical barriers and also utilize scare tactics and best gardening practices. The combination of protective netting, scarecrow devices, and cultivating a healthy plant can do more to keep your garden safe than any one method alone.
Who’s Eating my Tomato Plants? Find out here and what you can do about it!
FAQ
What eats the stems off of tomato plants?
Aphids, Whiteflies, Spider mites, Tomato Horn Worm: feeding on the leaves and bare stems.
What animal eats tomato plant stems?
If your tomato plants are being eaten and you have ruled out birds or insects as the culprits, animals could be the problem. Most gardeners are used to battling rabbits, squirrels, or deer but don’t think much about protecting plants from these other animal pests: Woodchucks. Gophers.