Week 4 - Troubleshooting Tomatoes

For episode/article 4 for This Week in the Garden, we’ll cover troubleshooting tomatoes. This was the #1 voted video from last week’s special edition poll. We’ll focus on early-season issues and how to prolong the life of your plants, but if you have any additional comments or questions, please fill out our form.

Starting from the beginning, the first issue you will see with tomatoes is stress from transplanting. Overwatering is the most common and will cause leaves to yellow and become soft. This can also lead to bacterial infections that we’ll talk about a little later. Underwatering is usually less of an issue because people are excited to be in their garden and taking care of their plants after the transplant. With underwatering, you’ll notice the leaves start to curl and become fragile. These issues may arise in an entire row, or in just a single plant in the row. In general, a light watering every day, to every other day is all you need for your transplants. This varies depending on a number of factors. Check out Week 3’s article for more information.

Another issue you may see early in the year is cold damage. This usually happens when temperatures get below 32 degrees for more than 4 hours. You may notice curled leaves, plants losing flowers, or brown/tan spots on the leaves. As long as the plants aren’t exposed to long periods of cold weather they should grow out of it. For more information on how to protect your plants from the cold, check out our article warning about last weekend’s cold weather.

While we’re still on the topic of cold weather, bacterial wilt is an issue you may see early in the year when the weather is wet and cool. Plants affected by bacterial wilt will have brown or yellow areas around the stem where the bacteria are growing. This will result in the plant slowly wilting. There isn’t much you can do at this point, but if you decide to replant, don’t put your tomatoes in the same area. Move the plants 6-12 inches from the infected plant, as these bacteria will be in the soil and can kill the next plant as well.

Finally, the last set of issues you might see in tomatoes are fungal and viral diseases. It’s still a little early in the year for most of these, but they’ll start showing up soon. Check out these posts from N.C. State and Clemson Universities to know what to be on the lookout for. Tomatoes are disease factories, and eventually, your tomatoes will get one. The goal with tomatoes should be to prolong their life so that you can get the most production out of the plant before it gets diseases. The best ways to do that are through proper watering and pruning.

The best way to water tomatoes to reduce disease pressure is by watering close to the base of the plant. That can be done with a soaker or drip hose or with a regular hose, being careful to not splash the leaves. A number of the fungal diseases are spread from the soil, so any reduction in splashing can help reduce disease incidence. Watering in the morning also helps as it gives the plant’s leaves time to dry.

Pruning is another way to reduce disease. You need to make sure you have a sharp, clean pair of pruners. You can clean your pruners with diluted bleach to reduce spreading diseases. When you’re pruning, you’ll want to remove yellow leaves. Leaves are yellow for a number of reasons including overwatering, not enough light, and disease. Regardless, these stressed leaves offer a suitable environment for diseases. Once pruned, make sure to remove the excised plant parts. Don’t compost these, as the spores can remain for extended periods of time.

That’s all for this episode/article of This Week in the Garden. Check out our new website where we’ll store all of our articles/videos in case you missed any. If you have any questions about any of our articles make sure to fill out our form.

-Adam