Problems with Tomato Seedlings:

Greenhouse seedlings don’t emerge or are small and weakened. Seedlings, once transplanted, die off quickly. Any plants that survive have the stems saturated with water near the soil.

Seedling Disease (Damping-off). Caused by the fungi Pythium and Rhizoctonia.

Plant seeds in high quality sterilized potting soil with low nitrogen levels.

Let the soil dry sufficiently before watering the seedlings again.

Add fertilizer only when the seedlings have emerged and are strong.

Flowers die off before the fruit sets.

Flower drop, due to extremely high or low temperatures.

Problem may correct itself as temperatures regulate.

The best way to avoid this problem is to plant your tomatoes when outdoor temperatures are stable.

Roots have galls or “knots.” Plants will not grow fully and may die off.

Root-knot nematodes. Microscopic worms in the soil and in the roots.

Pull up roots after the fall and destroy them. Move the tomatoes to another spot in the garden next season.
Plant marigolds to help reduce nematodes in the soil.

Solarize the soil (see our Expert Tips to Avoid Tomato Problems).
Buy tomato plants with the letter “N” following the name, indicating resistance to nematodes.
Nematode resistant varieties include: Sweet Cluster, Better Boy, Big Beef, Celebrity, Sweet Cluster, Keepsake.

Problems with Tomato Fruit:

Tomato fruits don’t appear.

Tomato fruits don’t appear.

Provide proper water and sunlight. Transplant seedlings only when temperatures are stable.
Try heat resistant variety “Sunmaster.” Use a superphosphate or 0-10-10 fertilizer to correct the nitrogen problem.

Cracking of tomato skin.

Growth Cracks, caused by rapid growth during ripening with extreme and varied weather conditions such as drought and heat, followed by heavy rains.

Regular watering. Buy resistant cultivars: such as Rutgers, Early Girl, Roma, First Lady, and Ball’s Beefsteak.

Green or yellow discoloration on the tomato’s “shoulders.”

Excessive temperatures causing “Yellow Shoulders

Reduce sun exposure.

Flowers die off before the fruit sets.

Flower drop, due to extremely high or low temperatures.

Problem may correct itself as temperatures regulate.

The best way to avoid this problem is to plant your tomatoes when outdoor temperatures are stable.

Tough, white splotches mostly on unripe fruit.

Sunscald, caused by extreme sun exposure.

Reduce sun exposure and check for pests that may be defoliating the plant.

Deforming of the fruit near the blossom end. Scarring and crevices.

“Catfacing.” Caused when plants have been set out too early in the season and exposed to the cold.

Avoid exposure to cold temperatures. Also check nitrogen levels.

End of the tomato is black and flat.

“Blossom end rot” due to changes in moisture and temperature, causing a calcium deficiency.

Proper watering is critical. Mulch can help retain moisture.

Make sure you plant your tomatoes when the spring temperatures are stable.

Small, dark raised circular dots to small circles on the fruit. Maybe deep-set in the middle with raised edges.

Can become crusted, scaly and split. On unripe fruit, a green ring may appear.

Bacterial Speck or Spot.
Bacterial Speck is caused by the bacteria Pseudomonas syringae. Forms as tiny dots on the fruit. Occurs during the warmest period of the growing season. It lives in leaf litter and plant debris.
Bacterial spot is caused by the bacteria Xanthomonas vesicatoria. Appears as large black discolorations. Occurs during the warmest period of the growing season. It lives in leaf litter and plant debris.

Treating the plants with mancozeb and copper after transplanting your tomatoes can help keep this problem at bay.
Use copper-based treatments to control the bacteria when the plants are small. Avoid buying starter plants with evidence of any kind of leaf spots.

“Bird’s eye” blotches. Small white or yellow raised areas. Can become crusted and scabby. Often accompanied by symptoms on the leaves and stems.

Bacterial canker, Clavibacter michiganensis. This disease often needs to be identified by a professional lab.

Spread by diseased seeds and transplants.

Can survive in the soil.

If the disease is confirmed, remove the diseased plants immediately.

You should avoid planting in this area for several years as the soil is also contaminated.

Circular and indented spots on the fruit that occur during early ripening, expanding to black areas with concentric rings and dark flecks. Rot appears in mature fruit. Symptoms may be delayed and appear later on harvested fruit.

Anthracnose, a fungal disease. Appears during the warmer weeks of the growing season as tomatoes ripen. Lives in plant debris and in the soil. It spreads by spores during rain storms or overhead waterin

Clean garden of debris and weed often. Mulch to reduce water splashing onto fruits. Separate and stake the plants to improve air circulation.

Don’t let ripe fruit sit on the vine for too long.

Wash the fruit to avoid the fungus appearing after the harvest.

Dark lesions with concentric circles on unripe fruit.
Often accompanied by other symptoms including brown to black cankers on stems near the soil and brown streaks on vascular tissue near the cankers. Near the end of the growing season the plants may die.
Dark areas on the leaves between the veins are another symptom.

Alternaria stem canker (Alternaria alternata f. sp. Lycopersici), a fungus.
Lives in plant debris and is spread through spores.

Remove plant debris that may host the fungus. Use drip irrigation to help avoid spreading the spores.

Ask your nursery for cultivars resistant this disease.

Small to medium sized brown lesions on ripening fruit. Lesions are sunken.
Warm, humid conditions lead to a smooth, black layer over the lesions.

Blackmold, Alternaria alternate, a fungus.

Use drip irrigation.
Do not leave the fruit on the vine for long periods after it has ripened.

Dark spots where the fruits are in contact with the soil. Spots grow larger with time and have concentric rings.
Symptoms are similar to late blight but the spots remain hard rather than soft and are not depressed at the edges.
White, fuzzy growth may appear, often rotting the fruit.

Buckeye Rot, a fungal disease caused by Phytophthora parasitica and exacerbated by warm wet weather.
May affect pepper plants as well.

Remove diseased plant material. Keep leaves dry with proper watering (drip irrigation recommended). Maintain proper soil conditions with good drainage.

Keep plants spaced, stake them, and mulch. Same fungicides work for blights and buckeye rot. Rotate plants often.

Virus-related tomato problems

Browning of the interior of the fruit.

Symptoms also appear on leaves.

Tobacco mosaic virus.

Spread through tobacco plants and products.

Infected plants and debris must be removed and destroyed to prevent the spread of the disease to healthy plants.

Buy disease resistant varieties.

Wash tools and hands frequently if you smoke.

Discoloration that resembles a yellowish ring accompanied by dark spots on the leaves. Can form cankers on the stems.

Tomato spotted wilt virus/impatiens, necrotic spot virus tospoviruses (TSWV or INSV). (More common for commercial tomato growers)

Unfortunately, the only way to treat the disease is to take out the diseased plants. Do not put them in the compost pile.

Insect-related tomato problems

Yellow discoloration of the fruit with distortion and yellowing leaves. Curling leaves.

Psyllids, small insects found on the underside of the leaf. Color varies from yellow to green.

Sulfur dust on the underside of the leaves.

Holes in the fruit and flower buds.

Tomato fruitworm, varying in color from brown to pink to green

Tomato fruitworm, varying in color from brown to pink to green
Remove and destroy the worm. Apply organic insecticide (see our organic treatments for tomato problems section)

Damage on the fruit, visible as small, uneven holes on the surface, occurring mid to late in the growing season.
Can be accompanied by damage on leaves and stems due to insect feeding.

Western Yellowstriped Armyworm, (Spodoptera praefica). Look for black larvae with yellow stripes.
A rare but potentially destructive insect. Worms may come from other crops including alfalfa and beans.

Use Bacillus thuringiensis ssp. aizawai or spinosad sprays which are used in organic gardening.

Chewing injury on green fruit and leaves.

Tomato/tobacco hornworm. Look for caterpillar type worms with markings and a horn-shaped structure on the end.

Remove the caterpillars and use an organic insecticide

(See our organic treatments for common tomato problems section)

Tiny dark spots surrounded by a light discoloration on unripe tomatoes. Areas are yellow or green on ripe fruit. Texture inside the tomato under the spots is spongy with a white coloring.

Stink bugs. Look for green to brown bugs decorated with red to yellow decorations.
They discharge a bad smell when touched.

Proper weeding is essential to control stink bugs as they make their home in nearby weeds.

Miscellaneous tomatoproblems

Miscellaneous problems
Dying flowers, fruit, stem, and/or leaf deformation.

Chemical damage.

Caused by residuals of lawn/garden care chemicals such as 2,4-D floating onto tomatoes.

Also caused by sprayers with herbicide residuals that have also been used to treat disease or pests.

Even more reason to go organic.

Track down the source of the contamination and stop it. Clean and sanitize all gardening equipment/sprayers.

Sudden wilting and death of tomato plants.

Walnut toxicity. A rare condition caused by proximity to the roots of black walnut trees.

Do not plant your tomatoes close to black walnut trees.

Problems with tomato leaves and stems:

Wilting leaves without vascular streaking.

Improper watering and/or temperature.

Monitor temperature, soil moisture, watering levels.

Wilting leaves with soft discolored roots.

Root rot.

Monitor soil moisture and watering.

Yellowing leaves without evidence of insects or disease.

Leaf scorching.

Monitor temperature, watering levels and salts.

During the first few weeks of the growing season, the leaves have turned purple with purple veins. There are no insects visible.

Phosphorus deficiency, occurring during the coldest months of the growing season.

Problem is not serious and will improve as temperatures rise.

Avoid this problem by planting your tomatoes when temperatures are stable.

Symptoms similar to Cucumber mosaic virus with curly, yellowing leaves and stunted growth.

Herbicide injury.

Monitor for recent herbicide application. Remove all infected plants and apply herbicide very carefully in the future.

Bacteria-related tomato problems

Vascular tissue filled with bacteria and slimy goo.
Plant wilts quickly but the leaves stay green. Check the stem for brown discoloring and a yellow slime.

Bacterial Wilt, also known as “Southern bacterial blight” caused by Ralstonia solanacearum.
This bacterium lives in the soil. Appears during the warm, wet period of the growing season.

Remove and destroy diseased plants. Rotate crops in infected soil with other plants such as corn and beans.
Avoid planting tomatoes, eggplants and potatoes in the same area for several years. Plant disease free tomatoes varieties.

Browning of the leaves and bottom leaves turn down. Coloring of the vascular system. Evidence of cankers on the stem.

Check for symptoms on the fruit.

Bacterial canker, Clavibacter michiganensis. This disease often needs to be identified by a professional lab. Spread by diseased seeds and transplants. Can survive in the soil

Take sample to a lab to confirm presence of the canker. Destroy the plants if confirmed.

Avoid planting for at least two years.

Black cankers on the stem.

Could be: Early blight (Alternaria), tomato spotted wilt virus/impatiens necrotic spot virus, bacterial canker

Take to a lab for proper identification.

See the solutions for problems with tomato fruits.

Fungus-related tomato problems

Yellowing of the leaves with vascular streaking on the stem. Leaves sag downward. Dark coloring of the vascular tissue of the stem. Plants can eventually wilt and die.

“Fusarium wilt” caused by the fungus Fusarium oxysporum.

Remove all plants and avoid planting tomatoes for at least two years. Watch for over-watering. Proper watering is critical.

Buy fungus resistant cultivars (VFN).

Light green or yellow spots on older leaves near the bottom of the plant. Leaves turn yellow as the fungus grows, or develop gray areas (fungal spores).

Foliage may begin to die off. Can attack the fruit as well, causing black rot near the stem.

Leaf mold, or “Gray Leaf Mold,” a fungus caused by Cladosporium fulvum.
Exacerbated by high humidity and low air circulation.

Use a fungicide while the plants are small. (see Early Blight).
Remove plant debris. Stake and space plants to promote air circulation. Keep leaves dry.
Use drip irrigation.

Rotate with vegetables other than tomatoes.

Brown to black cankers on stems and fruit. Cankers appear on the stems near the soil.
Nearing the end of the season, they can enlarge and the plants may die. Brown streaks on vascular tissue near the cankers.
Dark areas on the leaves between the veins are another symptom.
Symptoms may appear on fruits as well, including dark lesions with concentric circles on unripe fruit.

Alternaria stem canker (Alternaria alternata f. sp. Lycopersici), a fungus. Lives in plant debris and is spread through spores.

Remove plant debris that may host the fungus.

Use drip irrigation to help avoid the spreading of the spores.

Ask your nursery for cultivars resistant this disease.

Yellowing of the leaves.

Later, leaves turn dark and wilt. Vascular streaks on the stem.

Look for root rot and cankers.

Fusarium crown rot, caused by the fungus Fusarium oxysporum

Remove all plants and avoid planting tomatoes for at least two years.

Buy fungus resistant cultivars (VFN).

Watch for over watering. Proper watering is critical.

Dark areas surrounded by concentric ring on the older leaves. Yellowing leaves that often fall off.

Early blight (Alternaria solani).

Early blight often attacks plants that are too close together and very moist.

Space plants properly and use drip irrigation.
Clean up fallen leaves and remove the diseased parts of the plant.
Don’t plant tomatoes in the same part of the garden the following growing season.
Sulfur dust can also help.

Yellow, uneven splotches on the leaves. Dead leaves that remain on the plant. Dead areas can be surrounded by a yellow circle.
No damage to stems evident.

Powdery Mildew, a fungus that infects weeds and crops in the solanaceous family.
Occurs late in the season.

Sulfur sprays.

Spots with whitish center and brown or black edges.

Septoria leaf spot, a fungal disease. Usually occurring in hot, moist climates.

See treatment for Early blight

Virus-related problems

Yellowing of the plant. Plant doesn’t grow fully. Leaves may be dappled.

Cucumber mosaic virus.

Can be present in seeds or transmitted by aphids.

Remove and destroy all infected plants.

Entire plant turns yellow and ceases to grow. Some leaves become purple and roll up.

Leaves become tuff and fruit will ripen early.

Curly top virus, carried by the beet leafhopper.

Watch for leafhopper and use row covers.
Organic pesticides may have a limited affect.

Leaves are wrinkled with mottling, with symptoms on fruits.

Tobacco mosaic virus.

Spread by tobacco products or growing tobacco nearby.

Destroy infected plants.

Wash tools and hands frequently if working with tobacco or if you smoke.

Buy disease resistant varieties.

Dark spots (brown to purple) on the leaves, often with concentric rings. Look for dark areas on the stems with cankers and streaks.

Leaves become hard and often wilt.

Accompanied by fruit discoloration that resembles a yellowish ring.

Tomato spotted wilt virus/impatiens, necrotic spot virus tospoviruses (TSWV or INSV).

(More common for commercial tomato growers)

Unfortunately, the only way to treat the disease is to dig up the diseased plants and throw them out. Do not put them in the compost pile.

Insect-related problems

Yellow leaves with purple veins. Zig-zag pattern on the stems. Accompanied by yellowing and distortion of the fruit.

Psyllids, small insects found on the underside of the leaf. Color varies from yellow to green.

Sulfur dust on the underside of the leaves.

Entire plant turns yellow and ceases to grow. Some leaves become purple and roll up.

Leaves become tuff and fruit will ripen early.

Curly top virus, carried by the beet leafhopper.

Watch for leafhopper and use row covers.
Organic insecticides may have a limited effect.

Chewing injury on leaves and green fruit.

Tomato/tobacco hornworm.

Look for caterpillar type worms with markings and a horn-shaped structure on the end.

Remove the caterpillars and use an organic insecticide

(See our organic treatments for common tomato problems section)

Presence of tunneling in the stems. Plants may wither and eventually die.

Presence of tunneling in the stems. Plants may wither and eventually die.
Stalk borer.

White or purplish fly larvae that enter and bore through the stems.

Larvae breed in nearby weeds.

Frequently weed your garden. Find and kill the borer larva by opening the stem just above the entry hole.
You can then tie the stem and return to regular watering. Try organic insecticides. (See our organic treatments for common tomato problems section)

Damage on leaves from insect feeding.

Looper caterpillars. Look for small green caterpillars that arch their backs as they move.
Also look for flat eggs on the underside of leaves.

Look for beneficial insects such as parasitic wasps and encourage their presence.
Use Bacillus thuringiensis ssp. aizawai or spinosad sprays which are used in organic gardening.

Thin, white markings on the leaves.

Severely effected plants have large white discolorations on the leaves.

Leaves may begin to fall off.

Leaf miners, a small fly larvae. Most dangerous to young plants.

Attacks mostly in late summer.

Use organic sprays such as Entrust (with spinosad).
Be on the lookout for beneficial insects such parasitic wasps. Keep these insects alive as they feed off of leafminer larvae.
(See our expert tips section for more info.)

Tiny holes in the leaves, using affecting young plants.

Some damage underground may also be present.

Flea beetle. Look for tiny dark beetles on or near the leaves. They will move when touched.

Not a serious problem but may weaken the plant and create problems with other diseases.

Use organic insecticides if the problem doesn’t go away.

Rotate crops.

(See our section on organic treatments for more information.)

Damage on leaves and stems due to insect feeding, occurring mid to late in the growing season.
Can be accompanied by damage on the fruit, visible as small, uneven holes on the surface

Western Yellowstriped Armyworm, (Spodoptera praefica).
Look for black larvae with yellow stripes. A rare but potentially destructive insect.
Worms may come from other crops including alfalfa and beans.

Use Bacillus thuringiensis ssp. aizawai or spinosad sprays which are used in organic gardening.

Plants appear cut off at the base. Usually occurs on young plants only.

Cutworms.

Large, brown, black, or gray worms. Larvae make their home in lingering plant debris.

Use a wax paper collar at the base of the plant. (see our experts tips for avoid tomato problems)
Keep garden free of leaf litter and plant debris.
Till soil well before transplanting to eliminate plant debris.

Tiny yellow spots and thin webbing.

Spider mite, a minute, light brown mite which is almost impossible to see.

The webbing is the clearest evidence.

Spray off the mites with water. Organic pesticides and insecticidal soaps may work.

Yellowing leaves with insects and dew-like deposits (“honeydew”).

Whiteflies and Aphids.

Tiny insects often on the underside of the leaves.

White flies are light in color and will fly away when disturbed.

Aphids will not fly away and vary in color from black to green.

Damage usually minimal.

Wash with diluted Castille soap or organic pesticide.

Miscellaneous tomato problems

Black cankers on the stem.

Could be: Early blight (Alternaria), tomato spotted wilt virus/impatiens necrotic spot virus, bacterial canker

See solutions for problems with fruits.

Dying flowers, fruit, stem, and/or leaf deformation.

Chemical damage.

Caused by residuals of lawn/garden care chemicals such as 2,4-D floating onto tomatoes.

Also caused by sprayers with herbicide residuals that have also been used to treat disease or pests.

Even more reason to go organic.

Track down the source of the contamination and stop it.

Clean and sanitize all gardening equipment/sprayers.

Sudden wilting and death of tomato plants.

Walnut toxicity. A rare condition caused by proximity to the roots of black walnut trees.

Do not plant your tomatoes close to black walnut trees.

When in doubt about symptoms or how to treat your tomatoes, ask the experts!

The Cooperative State Research Education and Extension (CSREES) can help.