Common Tomato Issues

One of the best parts of summer in Texas is eating a homegrown tomato. However, eating them and growing them often resemble a love hate relationship. Throughout the summer, you face the constant threat of insects, diseases, heat, or drought ruining your garden. If you are lucky enough to have perfect growing conditions, be thankful, but if you are like most of us, conditions are rarely perfect. If you have ever wondered what is causing your tomatoes to crack, this article is for you. 

Splitting and Cracking. Heavy rain, especially after a dry spell, is the main cause of fruit splitting and cracking. This damage usually occurs as tomatoes ripen, though green fruits can be affected too.

Radial Cracking.

Photo Credit: NC Cooperative Extension

Cracks and splits occur when rapid changes in soil moisture cause the fruit to expand faster than the skin can grow. There are two main patterns of this damage, vertical and circular. Vertical splits along the sides of the fruits, known as radial cracking, are the most serious and common in hot, humid weather. Circular cracks around the stem end are called concentric cracking. Green tomatoes with either type of cracking will likely rot before they ripen if left on the vine.

Concentric Cracking.
Photo Credit: NC Cooperative Extension

For both radial and concentric cracking, it is best to harvest the fruit immediately before it can begin to rot. Tomatoes with cracks are still edible and can finish ripening indoors. However, any fruit that develops a sour smell or starts to ooze should be composted or discarded. Keep in mind, fruit that ripens off the vine or during cloudy, rainy weather will be less flavorful than those that mature fully in sunny conditions.

Blossom End Rot.
Photo Credit: UC IPM Project

Blossom End Rot. Fluctuations in soil moisture levels are also the most common cause of blossom end rot, a disorder where insufficient calcium in developing fruit causes the lower end to turn tan or black. Other causes include extreme temperatures, over-fertilization, and low soil pH. If your tomatoes develop blossom end rot, remove and compost them as they will not ripen normally. If you would like to know more about your soil conditions, contact the Rains County Extension office for information on soil testing. 

Leaf Rolling. 
Photo credit: AgriLife Today

Leaf Rolling. Tomato leaves can curl for several reasons, including wet weather. Leaf curling due to wet conditions is not serious and won't damage the plants or reduce yields. Some varieties are more prone to this than others. When excessive moisture causes leaf curling, leaves curl upward from the bottom of the plant first. These leaves may take on a leathery appearance but remain green and healthy.

The best way to minimize fruit cracking, blossom end rot, and leaf curling in tomatoes is to maintain even soil moisture levels by watering during droughts. Most vegetables need about one inch of water per week. Soaker hoses and drip irrigation systems are the best methods as they apply water directly to the soil, reducing evaporation and keeping plant leaves dry, which helps prevent leaf diseases. Mulching your vegetable garden also helps keep the soil evenly moist and reduces moisture-related problems.

Rainy weather and wet soil can also lead to wilt diseases and leaf diseases like early blight. If you suspect your tomatoes have a disease or insect problem, get an accurate diagnosis before taking any action. Contact the Rains County Extension office for assistance.

If you have questions or concerns, please contact me, (903) 473-4580 or email Sarah.Latham@ag.tamu.edu. To view upcoming events or additional information please visit https://rains.agrilife.org/ or follow Rains County AgriLife on Facebook.