Tomatoes, pride of the garden, have their share of problems

By Mark Flory, Miami County Extension Agriculture Agent

Mark Flory

Gardening is a hobby many people enjoy. But just because it is enjoyable does not mean it is easy. Those of you who have had a garden in the past, or have one now, know exactly what I am talking about. Keeping up with the weeds, insects and diseases in a garden can be quite challenging.

Although it is not possible to talk about everything that could show up in a garden, I will discuss many people’s pride of the garden. That is tomatoes.

Though most gardens do have tomatoes and most people you talk to like to eat tomatoes they can have their share of problems. I will focus on some of those problems.

I am going to hit on the more common problems in tomatoes we see in this area. The first problem is leaf spots on tomato plants. There are several different things causing them, but the most common are blight and septoria leaf spot. Leaf spots can occur throughout the growing season. Though usually they will not kill the plant it can cause serious defoliation and reduced fruit. To help with this problem there are several things you can do. Try to move your tomatoes to a different place in the garden every year. This will help the plants avoid last year’s residues. In the fall, either remove the plants or till them into the soil.

Another problem is sun scald on set tomato fruits. This is something you will see a little of almost every year, even if you are doing everything perfectly.

Sun scald is exactly what it sounds like. It occurs when it is really hot, bright and sunny. We also will see more sun scald damage when the plant foliage has been removed in some manner, taking away the plant’s natural ability to provide some shade for the tomatoes. It is a common problem if a strong wind, rain or hail has damaged some of the plant’s foliage.

The final problem I will mention is leaf roll in tomato plants. This problem is quite common. Several things can cause leaf roll on plants, including physiological and herbicidal factors. Physiological is when the plant rolls its leaves on its own. What causes this generally is when we have a fairly mild and moist spring that allows the plant above ground to grow rapidly. The problem with this is if the top side of the plant grows too fast the foliage can outperform the root system. Then when it gets warm and a bit drier, the plant can tell it has too much foliage for its root system and the leaf rolling is what the plant does trying to let the roots grow. This problem generally will correct itself, but mulch and light watering can help.

The other situation that can cause leaf roll in tomatoes is herbicidal overspray. With herbicide damage, the stem starts to twist in a curlicue way, and the leaves will have more of a cupped look than a roll. Before deciding it is herbicide damage, take a look at other plants in the garden sensitive to herbicides, such as peppers and potatoes, and see if they show signs of damage as well. If they are not showing any signs of damage, most likely the cause is something else.

To help avoid this problem you need to be proactive. Don’t spray any broadleaf weed killers in a close proximity to your garden. Disease and problems occur in everyone’s garden so don’t be discouraged or think it was something you did if problems occur.

If you have any questions about tomatoes, call me at the Miami County Extension office, 294-4306.