Early blight is more prevalent in hot, humid regions and remains in the soil for one year.
In areas impacted by early blight, choose disease-resistant cultivars with Resistant to EB (Early Blight) labels.
Lesions develop on stems and fruits.
Albert Fertl / Getty Images
The defoliation causes sunscald.
Management:Remove lower leaves, including up to a third of the infected foliage.
Do not compost affected plants.
alexandrumagurean / Getty Images
Prevention:Prevent early blight by watering at the soil level andmulching.
Keep adequate space between plants and rows; use stakes and practice good weed control.
Prune bottom leaves from plants and rotate tomato plants and other nightshades every two years.
Andrey Maximenko / Getty Images
Copper and/or sulfur sprays can prevent further development of the fungus.
Symptoms:In warm weather, theentire plant wilts downduring the day, often recovering at night.
Symptoms start on older, lower leaves and move upward.
Ganna Zelenska / Getty Images
Eventually leaves on one side turn yellow, dry up, turn brown, and fall off.
The inner tissue of the lower stem turns red or black.
Plants may die quickly or succumb in a week or more.
saraTM / Getty Images
Management:Treatment is similar for both types of wilt.
There is no fungicide for wilt; remove and dispose of infected plants and roots.
Prevention:Prevent the diseases by planting resistant varieties labeled VFN or FN.
Andrey Maximento / Getty Images
Keep tools clean and practice a three-year crop rotation.
Fusarium wilt is hosted by pigweed and crabgrass, so weed control is important.
Avoid excessive nitrogen fertilizers, which encourage disease.
travenian / Getty Images
Powdery Mildew
Ganna Zelenska / Getty Images
Powdery mildewspreads by three different types of airborne fungi.
The throw in of spore differs according to temperature, but high humidity levels increase disease occurrence.
Fruits do not develop powdery mildew, but defoliation leads to sunscald and crop loss.
Natalya Stepina / Getty Images
Symptoms:Yellow spots appear on leaves, turning towhite powdery lesionscoating the entire leaf and appearing on stems.
Remove infected leaves and buds.
Prevention:Prevent powdery mildew by allowing adequate space between plants.Prune tomato plantsfor good air circulation.
Natalia Kokhanova/Getty Images
Provide regular, consistent hydration at the soil level and avoid wetting leaves.
Anthracnose
saraTM / Getty Images
Anthracnose is a common fungal disease that causes fruit to rot.
It’s brought on by a fungus that favors warm temperatures, wet conditions, and poorly-drained soil.
Yevhenii Orlov/Getty Images
Overripe tomatoes that come in contact with wet soil are especially susceptible.
Leaves may develop small, round spots with yellow halos.
Infection starts in small, immature fruit, but symptoms don’t appear until ripening.
VladK213/Getty Images
Management:Copper sprays offer some resistance, but these fungicides are more effective as a preventive measure.
Avoid letting tomatoes overripen on the vine and dispose of rotten fruit and debris.
Practice crop rotation every two years along with other nightshades.
Mila Usmanova/Getty Images
Septoria Leaf Spot
Andrey Maximento / Getty Images
TheSeptoriafungus causesseptoria leaf spot.
The fungal infection affects leaves but not the fruit.
This fungus thrives in warm, wet weather, so watch for symptoms and act immediately.
_Vilor/Getty Images
Symptoms:Symptoms are similar to early blight, but septoria more often appears at the first fruit set.
This fungus appears on leaves as multiple small, dark circles that enlarge to 1/3 to 1/4-inch in diameter.
The spots develop a tan or gray center, and the leaves eventually wilt and fall off.
PaulMaguire/Getty Images
Early leaf drop leads to fruit loss and sunscald.
Copper sprays and Serenade fungicide are somewhat effective at halting the spread of symptoms.
Prevention:Good garden sanitation is critical for preventing septoria leaf spot.
alexandrumagurean/Getty Images
Remove fallen leaves and debris from the garden immediately.
Clean tools before and after working with plants, water at ground level, and control insect pests.
Rotate your tomato crops every three years.
Akchamczuk / Getty Images
Spores are spread by wind and water and are most prevalent in cooler temperatures.
Tomato flowers are also susceptible to this fungus.
Symptoms:Brown lesions appear on leaves and stems.
Rasbak / Wikimedia Commons / CC BY-SA 3.0
A whitish soft rot appears on fruits.
The mold causes tomatoes to rot after harvest.
Leaves die and fall off, and stem girdling leads to wilt.
Zarina Lukash/Getty Images
Management:Botrytis often dies back when temperatures rise.
Treat widespread or persistent infection with tomato fungicide or biofungicide with a specific software for gray mold.
Prevention:Prevent botrytis by pruning plants in the early afternoon, which allows cuts to dry quickly.
PaulMaguire/Getty Images
Avoid overhead watering and working with wet plants.
Leave adequate spacing between plants and rows for good air circulation.
The bacteriaPseudomonas syringaecause bacterial speckduring persistent cool, wet weather.
Photo by Cathy Scola/Getty Images
Bacterial speck spreads by splashing water on the leaves.
It can’t be cured, but there are steps to take to stop it from spreading.
Symptoms:Yellow tissue surrounds small, irregular, dark brown to black spots close to leaf margins.
saraTM/Getty Images
Spots appear raised on mature fruit, but they can also appear flat or sunken.
Management:Treat plants with a copper fungicide during cool, wet weather.
Hot weather stops the pathogen from spreading.
saraTM/Getty Images
Prevention:Delay planting until weather conditions are warmer and drier.
Avoid overhead irrigation and rotate tomatoes and other nightshades every year.
More prevalent in southern regions, it favors high temperatures, moist conditions, and acidic soil.
Natalya Stepina/Getty Images
Southern blight persists in the soil for years.
Young plants may collapse at the soil line.
Fruit near the stem can become infected, as well.
Tomatoes rot within three to four days.
Management:Fungicides and biofungicides can help manage southern blight.
Soil fumigants can be used, but are expensive.
Prevention:Preventive steps include polarization to kill spores, crop rotation, and maintainingsoil pH levelsfor tomatoes.
Avoid planting during wet weather with expected high temperatures.
Remove plant debris and till or disk the soil several times before planting.
Dispose of infected plants and plant debris, but do not compost.
Eliminate weeds and rotate tomatoes with non-host crops.
Symptoms:Small, dark spots with yellow halos appear on the top and bottom surfaces of the leaves.
The spots enlarge and turn a grayish brown.
Eventually, the centers of the spots crack and fall out.
Surrounding leaf areas will turn yellow, and the leaves will dry out and drop.
Fruit production is inhibited.
Management:Warm, moist conditions worsen gray leaf spot problems.
Remove all affected plants and fall garden debris.
Do not compost infected plants.
Prevention:Cherry and grape tomato plants are most often impacted.
Rotate crops to avoid planting in infected soil.
It develops in cool, wet weather and spreads rapidly.
Symptoms:Greasy-looking, irregularly shaped dark brown blotches with green-gray edges appear on leaves.
A ring of white mold develops around the spots, especially in wet weather.
The spots eventually turn dry and papery.
Blackened areas may appear on the stems.
Management:Copper sprays offer some control.
The fungicide Serenade works best as a deterrent rather than a cure.
Late blight can overwinter in soil, tomato debris, and seeds, even in colder areas.
Rotate crops to prevent infections the following year.
It’s a physiological disorder, not a disease, but it still results in fruit loss.
The spots look water-soaked.
Management:Remove affected fruit and provide regular, deep waterings.
Add garden lime to the soil to help plants uptake water and nutrients.
Use a fertilizer low in nitrogen and high in phosphorus.
Prevention:Water on a consistent schedule and provide well-balanced fertilizer.
Symptoms:A small brown spot will enlarge and develop concentric rings resembling a buckeye.
Management:Remove affected fruit.
Avoid surface water from flooding the plants.
Keep future fruits from making contact with the soil.
Gray Wall
PaulMaguire/Getty Images
Gray wall is essentially a ripening problem.
There’s no known associated pathogen or treatment, only preventive steps.
Cool temperatures and stressed or unhealthy plants contribute to the problem.
Symptoms:The green fruits may have a gray cast or flattened, gray blotches.
Ripe fruit has a mottled appearance and green or brown areas on the inside of the fruit.
Management:Good growing conditions help prevent gray wall.
confirm plants are not heavily shaded.
Evenly water and regularly fertilize plants.
Keep the soil from becoming compacted around the roots.
Prevention:Choose mosaic-resistant tomato varieties, promote healthy soil ecology, and fertilize plants properly.
Symptoms:Leaf mold appears as pale green or yellowish spots on the upper leaves.
Fruits can have a leathery, blackish rot near the stem.
Management:Increase air circulation by pruning, spacing, and staking tomato plants to control the disease.
Avoid watering overhead to keep leaves dry.
Tomato Pith Necrosis
Akchamczuk / Getty Images
Tomato pith necrosis is a disease brought on by soil-bornePseudomonasbacteria.
It occurs during cloudy, cool, and moist conditions.
Symptoms:An early symptom is the blackening of the stems and leaves.
Later symptoms involve split stems or stems that shrink and crack.
The pith (stem interior) disintegrates and becomes hollow, disrupting water flow, and causing yellowing leaves.
Management:Warmer weather can sort out the issue.
This fungus develops in cool, wet, and rich soils.
Symptoms:Seedlings may fail to emerge or the stems are water-soaked.
Addnitrogen fertilizerafter seedlings are more established, which is when they have their first true leaves.
It’s always good practice to keep the surface of the soil dry between waterings.
It’s also a difficult virus to eradicate since it survives in plant debris for over 50 years.
Symptoms:Curling leavesmay become mottled, new leaflets are small, and infected fruit is brown inside.
Growth can be generally light in color.
The fruit may have a mottled mosaic look (alternating colors) on the skin.
Management:Control of mosaic virus is difficult.
Reflective mulches may help prevent the problem.
The disease is more pronounced in the south, partially because it’s inspired by high temperatures.
Symptoms:Leaves will begin wilting and can turn yellow or brown, before the whole plant perishes.
Management:Remove infected plants immediately and dispose of them.
Do not plant solanaceous crops again in this area.
There is not much you could do once the disease sets in.
Prevention:Rotate crops regularly and sanitize all garden tools.
Keep weeds under control.
They can cause damage to far more than just your tomatoes.
Because they live in the soil, treatment and management can be tricky.
Symptoms:Your tomato plants may be stunted or wilting for reasons you don’t understand.
Symptoms from root knot nematodes are visible below ground when examining the roots.
Roots may be oddly swollen where root-knot nematodes have laid their eggs.
Sunscald
saraTM/Getty Images
In sunny regions, tomatoes can simply be burned by the sun.
Symptoms:Burnt, scalded tomatoes.
Management:Once tomatoes are burnt, there’s not much you’re able to do.
Erect some sort of shade structure to prevent remaining fruits and fruits that have yet to emerge.
Avoid pruning too aggressively.
Use management techniques to prevent other diseases that result in leaf loss.
Multiple bacteria are known to cause this disease, which results in spotty, pitted fruits.
Symptoms:Tomato plant leaves will develop small spots that are brown with a yellow ring around them.
These spots often fall away and leave holes behind.
Fruits may have scabby spots as well.
The leaves may be smaller than expected and will curl upward.
Flowers are more likely to fall off, resulting in less fruit.
Management:Remove infected plants and practice aggressive weed control.
Prevention:Serious crop rotation, avoiding fields where tomatoes with yellow leaf curl virus have been present.
Practice pest prevention, as the virus is often spread through whiteflies.
Here are symptoms to watch for and ways tokeep your tomatoes healthy.
Not all diseased tomato plants can be saved.
Tomato Diseases & Disorders.Clemson University Cooperative Extension Service.
Southern Blight of Tomato and Pepper.North Carolina State Extension.
Common Diseases of Tomatoes.Mississippi State University Extension.
Vegetable: Tomato, Buckeye Rot.University of Massachusetts Center for Agriculture.
Tomato Diseases and Disorders.Clemson University Cooperative Extension Service.
The Plant DoctorTobacco Mosaic Virus.Mississippi State University Extension.
Mosaic Diseases brought on by Potyviruses.
Marigolds for Nematode Management.
Bacterial spot of tomato and pepper.
University of Minnesota Extension.
Tomato Yellow Leaf Curl.
