If you thought your troubles were over once you got your tomato plants in the ground, then we’ve got bad news for you… having a garden is a constant battle against nature, and there always seems to be something just waiting to ruin your hard work. Bugs, diseases, and pests can turn your tomatoes into their own personal feeding ground if you’re not proactive. Don’t worry, it’s not all doom and gloom—we’re here to help you combat several of the common tomato plant problems that can occur.
Somehow, in the insect world, word travels fast when a new garden is taking shape and the pests know that it’s time to come take a look. From tiny insects you can barely see to palm sized hornworms that look like they could eat your fingers, tomato pests are a very real threat, yet easily treated.
Aphids are small green bugs that eat at your plants so slowly that at first, you barely notice anything is happening. Soon, however, the holes in your plants’ leaves will be obvious. Aphids usually invade in large numbers, but due to their light green color, they can be hard to see. If aphids have invaded your tomato plants, your first plan of action should be to remove the foliage where the aphids have gathered and throw them away in a closed container, not out in your yard or compost pile.
If the aphids have spread to multiple plants, your best bet may be to spray a solution of water, liquid soap, and oil. This solution is harmless to your plants but sticks to the aphids and suffocates them. Another great (and organic) cure for aphids is ladybugs! These little things, while cute and harmless to us, are actually aphids’ number one predator.
Hornworms can cause some serious damage to your tomatoes and they’ll eat the leaves, stems, and the fruit, and then move onto the next plant for desert. Luckily, hornworms are so large, they’re hard to miss if you routinely inspect your plants. The easiest way to take care of them is by pulling them off your plants and killing them or moving them very far away. Also, using a rototiller before planting your garden may also help destroy the hornworm larvae before they become a nuisance.
Don’t just keep an eye on the tops of your tomato plants—you have to look on the ground as well. Cutworms are gray caterpillar-like worms that like to chew on the bottom stems and leaves. Worst of all, they tend to only attack at night, making it even harder to see them. Inspect your plants’ stems and leaves in the evening, and if damage is present, you’re probably looking at a cutworm problem.
There’s an easy fix for preventing cutworms, called cutworm collars. Use foil or cardboard to make a tall circular barrier that extends all the way around your tomato plant’s base and bury the barrier about an inch into the ground. This will prevent cutworms from climbing up and munching on your stems and foliage. As an added measure, try spreading diatomaceous earth onto the soil to help kill cutworms.
Several types of beetles can wreak havoc on your tomato plants, but there usually isn’t a sure way to prevent them from coming. If you notice a lot of beetles hanging around your tomatoes, try that handy mixture of water, liquid soap, and oil to help deter them from landing. If you see any beetles chomping on your plants, simply pull them off and drop them into a bucket of water.
Rainy weather, combined with high temperatures and humidity, can cause several debilitating tomato plant diseases and fungal infections. While the weather is uncontrollable, many remedies exist to help alleviate a sick tomato plant.
Blight is a fungal infection characterized by small, black lesions that appear on the plant’s foliage. The area around the spots may turn yellow as time goes on. This infection can spread over to the fruit, making it inedible.
Septoria leaf spot is a disease characterized by brown spots that usually appear on the foliage closest to the ground. Unlike blight, septoria won’t produce a yellow ring and won’t damage fruit.
Proper fertilizing, weeding, debris removal and use of resistant tomato strains usually helps prevent these diseases. Remove infected foliage with pruners and place in the garbage—not on the ground.
Ensure you clean your pruners with rubbing alcohol. A good rule to remember is to avoid getting the foliage wet during watering. Try to aim the water only towards the soil. Some gardeners recommend using different parts of your garden every year to prevent a build up of disease and fungus. If these problems persist, many commercial fungicides and are available, such as sulfur powder, maneb, and mancozeb.
Tomato rot occurs when the end of a tomato fruit has a black diseased looking hole. Sometimes it’s very small and can be removed when you go to eat the tomato, but often, it ruins the entire tomato. While it may not seem obvious, the number one cause of tomato rot is due to a calcium deficiency. Just like humans, plants need calcium to survive. When a fruit or vegetable is deprived of calcium, its tissues break down, thus resulting in rot. Too much ammonium sulfate from inorganic fertilizer, excess moisture, and low phosphorous levels can cause a calcium deficiency.
You can prevent tomato rot by enriching your garden with organic compost, especially egg shells. Bone meal is also a great source of calcium, but these solutions won’t have an instant effect, so you should be doing this throughout the year to replenish your soil’s calcium. Once rot appears on a tomato, there’s no way to cure it.
There is no surer sign that something is wrong than a wilting plant. Tomato wilt is one of the most serious tomato plant problems and can be a heartbreaking sight for any gardener. Several factors can cause tomato wilt, such as over-watering, lack of water, or infection.
It can be hard to tell if you’re giving your tomatoes too much water or not enough, but as a general rule, a tomato plant needs about 1 inch of water a week. If correcting the amount of water your plants are getting doesn’t fix the wilt, your tomato plant could have an infection. Tomato wilt as a result of infection is characterized by a sudden wilt but the foliage is still green. Adjusting the water regimen won’t cure the problem. There isn’t a cure other than pruning the wilted foliage
To prevent tomato wilt, use organic fertilizer, weed and remove the debris at least once a week, and use wilt-resistant tomato strains. Again, when watering, try to only water the ground and not the tomato’s leaves.