Don’t overwinter your plants and remove any volunteer tomatoes and potatoes that come up.If you have an outbreak, rotate your crops even if you have to plant in containers.Make sure your garden area is cleaned up promptly at the end of the summer gardening season and there isn’t any plant debris lying around.Do use caution with the copper – spray early in the morning to avoid harm to bees, and because it can build up in the soil and cause toxicity, don’t grow tomatoes in the same spot every year if you’re going to use copper frequently. Don’t spray them together on the same week as there is some question as to whether the copper inactivates the Serenade. If you see anything that even remotely looks like blight, begin a spraying program of alternating organic copper spray, and Serenade biological fungicide, both of which are safe to use on edibles.Check your plants frequently during wet weather or if they are stressed.Add a layer of mulch or use those red plastic tomato mulches they sell as a barrier between tomato foliage and soil, as the fungus can be carried in the soil.Make sure there is enough space between your plants for air circulation.First of all buy your starts and seeds from a reliable source – don’t just take starts off friends or well-meaning neighbors.Grafted tomatoes can be much more vigorous and better able to shake off stresses. If you can find grafted versions of tomatoes that are bred for disease-resistance, all the better. Methods to control blight Plant blight-resistant tomato varieties

Gardeners across the country suffer from both early and late blight. Late tomato blight shows up in cool and wet weather in mid-to-late season and can kill a plant within a week.Ĭalifornia’s Humboldt County and the coastal Pacific Northwest has such cool, damp summers that our tomatoes often suffer from blight – though it’s by no means limited to the Northwest region. The spots on the leaves and fruit may have a cottony looking ring of white mold and the leaves will eventually fall off.

The fruit will have brown greasy spots which are shaped irregularly. Late blight shows up as blue-gray spots which then turn brown, and it affects both the leaves and the fruit. If a plant becomes infected, it has to be destroyed and taken off-site (not composted). It’s highly contagious and can spread from your garden to a neighboring gardener’s plot in the breath of a spore carrying wind. It can ruin a whole crop and infect other plants quickly. The name of this fungus is called Phytophthora, which means “plant destroyer”. Late tomato blight is just plain bad news all the way around. While early blight is a nasty disease, it’s not as devastating as late blight. Your plants may survive this attack but there won’t be as many tomatoes. The spots will be dark leathery and sunken with concentric rings and it will affect your ripe and unripe tomatoes. When it’s on your fruit, the spots show up near the stem. Spots which are on the stem near the ground can cause the stem to girdle. The spots may start out small and shrunken and as they get bigger they get longer. Like with most pests and diseases, plants which are stressed or just in plain poor health are more susceptible.Įarly tomato blight forms spots on the leaves, which then turn yellow and die. It may not outright kill the plant but it will weaken it and the yield may be smaller.Įarly blight loves damp weather and heavy dew, it can be in the soil, or it can overwinter in diseased plants from the year before if you didn’t clean up the vegetable garden promptly. This fungus can affect almost every part of the tomato such as the stems, leaves and fruits. What is going on? You guessed it: you may have tomato blight.Įarly tomato blight is caused by a fungus called Alternaria solani. The leaves are watery and rotten looking and there is a brown lesion on the stem. Homemade tomato sauce canned and stacked neatly on shelves, stewed tomatoes in jars, tomatoes on salads and just taking a big juicy bite out of one straight out of the garden – you can almost taste it! You go out to your garden to do your checkup and daily watering and see something odd on one of your tomato plants. You have visions of homegrown tomatoes dancing in your head.

Kill tomato late blight