Tomato Diseases

"From Anthracnose to Verticillium Wilt"


If you follow good tomato gardening practices then tomato diseases is a topic you can hopefully avoid. Unfortunately conditions for growing tomatoes are never perfect and you may find yourself saying, "what in the world is wrong with my tomatoes!"

Anthracnose tomato disease blossom-end rot in tomatoes tomato catface chlorosis virus in tomatoes crown rot disease in tomatoes damping-off tomato disease early blight tomato disease fusarium wilt tomato disease gray leaf spot tomato disease late blight tomato disease leaf mold tomato disease powdery mildew tomato disease pythium tomato disease septoria leaf spot tomato disease stemphylium tomato disease sunscald tomato disease tobacco mosaic virus tomato disease tomato spotted wilt virus tomato disease verticillium wilt tomato disease

Good tomato growing practices help prevent tomato diseases

Following these basic practices is always a good idea to promote a healthy garden:

  • Rotate your crops by not planting tomatoes in the same soil where tomatoes, peppers, potatoes, eggplant have been planted for at least two years.
  • Stake and mulch tomato plants to keep foliage from being in contact with the soil.
  • If watering from overhead, do it early in the day to allow the sun to dry the leaves.
  • Use disease-free certified seed or treated commercial seed.
  • Use fresh deep soil with good drainage.
  • Inspect tomato seedlings before planting and destroy any that show disease signs.
  • Increase the amount of organic matter in the soil. In particular, well rotted manure will increase fertility and decrease nematodes.
  • Use "green manure" nitrogen fixing legumes in the off-season to increase fertility of your soil for tomatoes.
  • Use frost protection techniques to avoid tomato diseases encouraged by too low temperatures.
  • Follow my 5 Best Tomato Growing Tips

Common Tomato Diseases

Got a question about tomato diseases or pests? Ask here. We have the most amazing group of visitors who answer your questions. It's help and be helped!

Anthracnose

  • Symptoms
    • small circular, slightly sunken water-soaked spots that get darker and deeper or ring markings
    • A slightly soft decay occurs as the fungus spreads
    • Lesions merge into a large rotted area
    • This tomato disease infects both green and ripe fruit
    Causes
    • root disease survives in infested tomato plant debris
    • attacks ripe tomatoes   
    • encouraged by infertile soil, poor drainage
  • Controls:
    • enrich soil with organic mulches
    • improve drainage
    • rotate crops in 3- to 4-year cycles
    • protect against rain splash
    • dispose of diseased fruit
    • dust with fungicides

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Bacterial Canker

  • Symptoms
    • seedlings die or produce weak, stunted plants
    • wilting, curling and browning of leaves
    • leaf rolling
    • later bird's-eye spots on fruit - whitish-brown spots with a white halo and raised dark brown center
  • Cause
    • contaminated seedbed soil
    • infected seeds
  • Control
    • one of the most difficult to control tomato diseases
    • use only treated seed
    • rotate crops
    • don't add old tomato or potato fruits or their foliage into soil

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Bacterial Spot

  • Symptoms
    • Infected leaves show dark lesions
    • Yellowing leaves
    • Blossom drop
    • small, dark, slightly raised dots with a water-soaked border quarter-inch in diameter
    • center of spot is slightly sunken with a rough surface
    • is similar to Bacterial Speck but actually a different bacteria
  • Causes
    • ripe fruit is not affected
    • may be carried by tomato seed
    • carried by windblown soil or insects
    • sometimes present on transplants produced in southern U.S.
    • spread by wind-blown rain
  • Control
    • same as for bacterial canker
    • Use disease-free seed from western states or hot-water treated seed
    • rotate crops from year-to-year
    • Apply a mixture of mancozeb plus copper during early flowering and fruit setting periods

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Bacterial Wilt

  • Symptoms
    • Tomato disease with no visible spotting or yellowing of leaves
    • Stems at ground level may be water-soaked and emit slimy ooze when pressed
    • Often called brown rot
    • rapidly kills entire plant
  • Controls
    • don't grow tomatoes in the same spot for 4 to 5 years
    • Grow seedlings only in pasteurized soil
    • destroy all diseased plants
    • grow disease-resistant varieties like Venus

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Blossom End Rot

  • Symptoms
    • Slight water-soaked spot near blossom end of fruit
    • One of the most common tomato diseases
    • Sunken spot turns flattened, black, and leathery
    • Appears on first fruits
  • Causes
    • Moisture fluctuations
    • Lack of calcium during drought spells
    • Planting early in cold soils
    • Soils contain excessive amounts of salts causing a decrease in calcium availability
  • Controls:
    • Keep soil moisture constant with mulching and consistent watering
    • Soil should have good drainage
    • Don't fertilize with too much nitrogen
    • Test soil for calcium deficiency
    • Don't cultivate too close to plant, thereby damaging roots
    • Use resistant varieties like Marglobe

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Buckeye Rot

  • Symptoms
    • Water-soaked brown or grayish-green spots near blossom end
    • Spots located where fruit touches the soil
  • Causes
    • A disease that only affects tomatoes
  • Controls
    • Have soil with good drainage
    • Don't wet plants when watering
    • Stake so fruits don't contact soil
    • Don't plant tomatoes in same spot every year - instead, rotate crops

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Catfacing

  • Symptoms
    • severe scarring at blossom end of fruit
    • bands of scar tissue
    • swollen bulges
    • fruit puckering
    • more severe on first fruits and large varieties
  • Causes
    • The flowers are harmed when very small
    • temperatures are too cool
    • Pesticide effects - particularly 2,4-D
  • Controls
    • Grow hybrids instead of heirloom varieties
    • Plant later when warmer
    • Use frost protection of tomato plants in garden beds

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Chlorosis

  • Symptoms
    • Another of the tomato diseases that causes yellow foliage
  • Causes
    • Excess lime
    • Iron deficiency
  • Controls

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Cloudy Spot

  • Symptoms
    • Blemishes on green or ripe fruit
    • Spots are one-eighth to one-quarter cream colored spots
    • As fruit matures spot color changes to yellow
  • Causes
    • Stink bug feeding
  • Controls
    • Use weed control strategies where stink bugs live
    • Hand pick insects from plants

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Cucumber Mosaic

  • Symptoms
    • Stunted growth of young plants
    • One of many tomato diseases that is shared with other plants
    • Odd stringy shoestring-type leaves
  • Causes
    • Virus spread by aphids
    • Not seed borne like tobacco mosaic
  • Controls
    • control aphids
    • separate plants from nearby weeds, flowers, cucumbers, melons, or peppers
    • Keep virus hosts phlox, petunias, hollyhock and zinnias at a distance

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Curly Top

  • Symptoms
    • This tomato disease exhibits leaves that are curly and twist upward
  • Causes
    • Is a virus spread by leafhopper insects
  • Controls
    • Eliminate leafhoppers
    • Reduce plant spacing more than normal
    • Don't plant beets nearby
    • Plant late varieties rather than early varieties

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Damping Off

  • Symptoms
    • Seedlings rot away at the base
  • Causes
    • Various fungi
  • Controls

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Double Virus Streak

  • Symptoms
    • A tomato disease typified by dead areas in leaves that form along the leaf veins
    • Brown streaks along main stem
    • Dry shrunken spots on green fruits
  • Causes
    • Mosaic viruses
  • Controls
    • Suppress weed growth around tomato plants
    • Avoid handling tobacco before handling plants
    • Rinse your hands in a water/milk solution
    • Spray plants with a 50-50 solution of water/milk

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Early Blight

Early blight is one of the most severe tomato diseases affecting home gardeners and can affect the stems, leaves, and fruit of tomato plants. It can also cause damping-off in seedlings. It doesn't occur in arid dry regions but is most active in warm, wet or rainy conditions. More about early blight...

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Fusarium Wilt

  • Symptoms
    • Fungus occurring after soil temperature reaches 75- to 85-degrees
    • Yellowing and dying of lower leaves
    • Eventually entire plant wilts
  • Causes
    • Fungal infection starting in roots which blocks water and nutrient flow to plant
  • Controls
    • Rotate crop especially if disease occurred prior years
    • Buy or grow seedlings grown in sterile/clean soil
    • Remove weeds from garden
    • Grow resistant tomato varieties

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Ghost Spot

  • Symptoms
    • Fruit has small white circles surrounding a green center
    • First spots appear on shoulders of green tomatoes
  • Causes
    • Fungus
  • Controls
    • Avoid planting in cool, damp conditions
    • Rotate crop every year

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Gray Leaf Spot

  • Symptoms
    • Leaves have small gray-brown spots on underside
    • In the U.S. this tomato disease is primarily a problem in Southeast states
    • Leaves turn yellow and drop off
  • Causes
    • Fungus
  • Controls
    • Destroy all infected plants at season end
    • Plant resistant varieties

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Gray Mold Rot (aka Botrytis Blight)

  • Symptoms
    • First symptom is gray spots on leaves and black marks on stems
    • Occurs mainly in greenhouses
    • Fruit has gray-green or gray-brown decayed spots
    • Is a major cause of rot of plant produce in tomatoes and other vegetables
  • Causes
    • Fungus Botrytis cinerea
    • Airborne fungus attaches to injured tissues
    • In greenhouses conditions of high humidity and cool conditions predispose
  • Controls
    • Fungicides will help protect but will not suppress and established infection
    • Treat the crop with fungicides before infections build up
    • Lower humidity and raise temperature   

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Graywall

  • Symptoms
    • Blotchy ripe fruit
    • Fruit has internal brown areas
  • Causes
    • Unknown, insufficient sunlight suspected
  • Controls
    • Plant in a sunnier spot
    • Don't over-fertilize with nitrogen which promotes excessive foliage cover

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Hard Core

  • Symptoms
    • Hard centers in ripe fruit
  • Causes
    • Temperature fluctuations, esp. low night temperatures
  • Controls
    • Discourage this condition and other tomato diseases by providing warmer, more consistent growing temperatures using frost protection techniques

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Late Blight

Late blight is a destructive tomato and potato disease that is sometimes confused with early blight, but is actually a very different pathogen. It generally develops at cooler temperatures than early blight. Pictures and more about late blight...

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Leaf Mold

  • Symptoms
    • Leaves have yellow or green spots
    • Leaves have purple mold areas
  • Causes
    • Fungus
    • Damp, wet weather
  • Controls
    • Don't irrigate in the evening
    • Water plants at base, not overhead to avoid wetting leaves
    • In greenhouses, keep temperature above 60˚F (15˚C) and humidity low

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Leaf Roll and Leaf Curl

  • Symptoms
    • Curling/rolling/dropping of leaves, usually stops after temperatures rise
    • Not one of the serious tomato diseases--usually clears up once temperatures warm
  • Causes
    • Physiological disease
    • Wet spring weather
    • Poor soil drainage
    • Close cultivation
    • Over pruning
  • Controls
    • Plant in well-drained soil
    • Use straw mulch
    • Don't stake or prune plants

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Nailhead Spot

  • Symptoms
    • Fruits have smallish tan or brown spots
  • Causes
    • See early blight for causes and controls of this tomato disease
  • Controls
    • Plant resistant varieties

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Potato Y Virus

  • Symptoms
    • Yellowing of younger leaves
    • Wilting plants
    • Purple streaks on stems
  • Causes
    • Virus transmitted from potatoes by aphids
  • Controls
    • Control aphids
    • Don't plant tomatoes near potatoes

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Septoria Leaf Spot

  • Symptoms
    • Leaves have small 1/4-inch gray water-soaked spots
    • Centers of spots have many dark brown, pimple-like structures
    • Spots appear on plant but rarely on fruit
    • Infected yellow leaves are dropping from plant, resulting in sunscalded fruit
  • Causes
    • Fungus
    • Spread by windblown water, splashing rain, pickers and beetles
    • Rainy weather favors disease development
  • Controls
    • Keep garden weeds controlled and plant debris removed
    • Use only disease-free seed
    • Use fungicides to control

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Soil Rot

  • Symptoms
    • Fruits have small brown circular spots on lower half
    • As fruits ripen, spots diminish but decayed areas enlarge and split
  • Causes
    • A fungus harbored in the soil
  • Controls
    • Stake or cage plants, keep fruit off ground
    • Remove any decayed or infected plant material
    • Have well drained soil

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Tobacco Mosaic Virus

  • Symptoms
    • Rough textured yellow and green mottling of leaves
    • Leaves brown and drop off
    • Stunted plant and poor fruit yield
  • Causes
    • Most common virus affecting tomatoes
    • Transmitted by aphids
    • Remains in soil in weed roots
    • High soil moisture
    • Low nitrogen and boron in soil
  • Controls
    • Suppress weed growth around tomato plants
    • Use disease-free certified seed
    • Avoid handling tobacco before handling plants
    • Rinse your hands in a water/milk solution
    • Spray plants with a 50-50 solution of water/milk

Back to List of Tomato Plant Diseases

Verticillium Wilt

  • Symptoms
    • Yellow splotches on lower leaves later turning brown
    • Lower leaves drop off plant
    • Plant wilts during day and recovers at night
  • Causes
    • Common fungus living in the soil
    • Dead stem tissue retards nutrients from roots
    • Cool, moisture-saturated soil
  • Controls
    • Plant verticillium wilt-resistant varieties
    • Keep garden free of weeds and remove plant debris
    • Don't mulch tomato or potato plants - they can harbor the disease
    • Long crop rotation of four to five years with nonrelated crops
    • Well-drained soil
    • Not over-watering

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Other good web resources on tomato diseases



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