Tomato leaves are curling

by Tony
(Burbank, CA)

Q. I have just noticed that my tomato leaves are curling. The flowers are starting to dry up but I do not see any spots. I was told is early blight. Should I just dispose of all plants? And if I do, can I plant some new plants in the same bed or is it better to wait till next season?


A. Tony, sorry to hear about your tomato leaves. Early blight is a tough one. We have it every year, it seems, on at least a few plants. The fungus overwinters in the soil. That's why it's a good idea to rotate where you grow your tomato plants each year.

If you anticipate dealing with early blight (as we do), start spraying for diseases soon as you plant them. It's so hard to get ahead of this problem, so focus on prevention. You can treat organically with copper spray or biofungicide Serenade. Or apply a fungicide such as chlorothalonil (sold as Fungonil), Mancozeb, or Daconil.

Read the early blight page and a few others to make sure that's what's ailing your plants. You may have been given accurate info or not. It's your plant. You get to decide what you have!

Leaf curl by itself is not a big deal. I get it every year. It has no effect on the fruit production. (Check out this page that lists 3 additional leaf curl causes.)

Flowers drying up before they set fruit is a bigger problem. If it continues all season, you won't get tomatoes - a true bummer. Flowers may fail to set fruit because of extreme temperatures. If it's too cold, the pollen dies and doesn't correctly fertilize the ovary. If it's too humid, the pollen clumps and doesn't fall on to the stigma easily. If you've been having high and low temperatures, they may be to blame. Sustained temps above about 85 F to higher can cause pollen to become what's called denatured, meaning it's inactive. You could try some tomato blossom set spray to help with pollination - gardeners have said they have used this with success. And read more about this frustrating issue on our blossom drop page.

You have a long growing season in LA - and probably a second season in the fall. I'd be tempted to start another plant or more if you have room. Don't pull this one up until you know for sure it is a blight. If you determine that it is, then be ruthless and completely dispose of it and the dirt, debris, and leaves on the ground.

Good luck and happy gardening!
Your friends at Tomato Dirt