The Rockdale Gardener

Gardening Posts From Rockdale Cooperative Extension

Leaf Curl in Tomatoes Can be Caused by Many Things

We see many tomatoes with curled leaves here in the Extension Office’s plant disease lab. Most of the time I deliver the happy to news to my clients that leaf curl won’t kill their tomatoes.

Curved leaves can be caused by many things. The damaged leaves might be a result of weather conditions; too cool mornings and warm afternoons.

Or irregular watering can cause plants stress. Too little water and the leaves wilt. Too much water and the leaves curl due to root loss caused by root rot.

We have to determine if clients have ever used a herbicide near their plantsRound Up can damage tomatoes if sprayed too near the plants. Round Up damaged plants often turn yellow. Three-way herbicides for lawns applied too near gardens can cause leaf curl. Herbicide residues from hay such as picloram from Grazon can cause curled leaves in tomatoes years after the hay is harvested. Grazon is used in the production of Bermuda hay particularly. Before using hay as a mulch you should know how the hay was managed. Tomatoes die quickly when exposed to these chemicals.

If a gardener recently applied manure prior to planting then there may be excessive salt concentrations in the soil, which would lead to the wilting of foliage even with proper soil moisture.  Only use aged manure to prevent soil salt levels from getting high enough to stunt tomato seedlings and transplants.

bacterial wilt streaming tomato

Stems affected by Bacterial Wilt will ooze bacterial slime when suspended in water.

tomato row

A row of beautiful tomato plants is every gardeners goal.

Bacterial wilt affects tomatoes quite regularly. The bacteria clogs the water carrying tissues of the plant, slowly cutting off its water supply. You can use the suspension-method to look for signs of bacteria; cut the stem to see if the sap is sticky and when suspended in water it the sap will pull white strings as it falls through the water. This method is not 100 % diagnostic.

If you are having trouble with your tomatoes, please give us a call!

Tomato Curl2

Leaf curl in tomato can be caused by many factors including powdery mildew

tomato problem

Round Up damage on tomato.