Tomatoes are probably the most popular vegetable – yes, I know they are technically a fruit – in the garden. But they are not without pest and disease issues. Today we’ll discuss how to resolve some of these tomato issues.

Types of Tomatoes

The notorious tomato hornworms

Tomato hornworms are probably the most notorious tomato pest simply because they look the most intimidating. The caterpillar of the hawk moth (Manduca quinquemaculata), it’s a toss up whether you should eradicate or tolerate them. They are capable of significant damage, so if the pest pressure is too great, there are a number of options.

~ Hand pick. Because tomato hornworms are up to 3 inches long, it is typically easy to find them to pick off  the offenders. Wear gloves and drop them into a bucket of soapy water.

~ Use Bt. Bacillus thuringiensis is an effective, natural treatment against tomato hornworms.

~ Sprinkle with diatomaceous earth. DE is a go-to for neutralizing most caterpillar species as the sharp, microscopic edges of these fossilizing ancient sea creatures destroy their soft exterior.

~ Till in the fall. Even though many people prefer leaving the garden as is for the winter. If you have a tomato hornworm problem, till the area once the harvest is complete. The hornworm larvae doesn’t burrow very deeply and you can take care of a lot of them at this time.

When aphids and blister beetles visit

Of course, aphids are also issues for tomatoes. But they are usually easy to handle. Wash them off with a spritz of water, rubbing the stems between your fingers. As I’ve mentioned before, aphids are weak and are easily killed. The gross factor on this is too much, use and insecticidal soap to do the job.

While blister beetles tend to prefer things like Swiss chard or Brassicas, they can attack tomato plants and will strip the foliage remarkably fast. If they are desperate and hit your tomatoes, the best course of action is to use a vacuum to suck them off the leaves. Do not touch them as the substance they exude can cause blistering.

Physiological issues

The number one physiological issue for tomatoes is undoubtedly blossom and rot. The classic sign is a perfectly beautiful tomato that has a brown leathery patch on the bottom. This is a situation where the plant is not taking a calcium sufficiently. This can be from calcium deficiency in the soil, an imbalance of other micronutrients, inadequate watering, or even high humidity or low temperatures. As you can see it is not a quick fix for everyone.

To start add calcium to your soil constantly. This can be a mineralized form, such as bonemeal or gypsum, or something as simple as crushed eggshells. The important thing is to continually amend it because it takes several months for the mineral to be accessible to the plants.

The next step is to ensure adequate watering. If you find this difficult, particularly in arid regions, put your tomatoes on a timed watering schedule. It is more difficult to control the humidity or the temperature. Just know that if you have a blossom and rot issue and you were doing everything else, those two factors may be the culprit.

Disease as tomato troubles

Tomatoes canned succumb to a number of diseases, particularly in areas that are warm and humid, which is what they like the best.

Early blight of tomato

I think the most feared disease issue is blight. Early and Late Blight are both fungal diseases. The Early Blight (Alternaria tomatophila or Alternaria solani) typically has  yellowish lesions on the leaves and sometimes the fruit. Late Blight (Phytophthora infestans) tends to occur when the weather is cool, yet humid. These early lesions look like dark water spots on the leaves, but spread quickly, ultimately destroying the entire plant. Your best protection against these fungal issues is planting blight resistant varieties.  If you are impacted by infection, remove all of the disease plants, and destroy them completely. And do not plant tomatoes in that area again for many years.

Bacterial spot (Xanthomonas vesicatoria) is identified by the tiny spots on the leaves, which also turned yellow, as well as the green fruit. If it looks like somebody took a ballpoint pen and put dots all over your green tomatoes, consider it bacterial spot. Spray the affected plants with a copper fungicide.

These are just a few of the common tomato issues. Although they can be susceptible to pests and diseases, if we plant resistant varieties and are diligent about keeping an eye on pest pressure, we will be rewarded with a bounty of tomatoes.