Experts and BHG readers answer.
Tomato leaves curling
Thanks for writing. There are actually several conditions that can cause tomato leaves to curl. The most common conditions are:
Environmental Stress --- such as too much water, too much fertilizer, or transplanting shock.
Herbicide injury --- if any chemicals were sprayed nearby (by you or even your neighbors), they may have drifted onto your tomato plants.
Disease -- viral diseases can also cause tomato leaves to curl. If your tomato plant is infected with a virus, the leaves will usually be mottled in color and the whole plant will appear stunted. (If it is a virus, the best thing you can do is throw the tomatoes in the trash and plant new ones in a different spot.)
---Justin, Senior Garden Editor, BHG.com "