Problems of Tomatoes

Tomato problems range from fungal diseases and pests to nutrient deficiencies and fruit damage. This guide covers the most common issues with a quick-reference chart so you can identify and fix the problem fast.

TLDR: Common tomato problems include fungal diseases (early blight, wilt), pests (hornworms, aphids, flea beetles), and fruit issues (blossom end rot, sunscald, catfacing). Use the chart below to match your symptom to a cause.

Key Steps to Prevent Tomato Problems:

 Use Actinovate Often

 Actinovate is a biological fungicide that when used properly will prevent most fungal diseases as well as the dreaded root knot nematode.  At until you have fixed the soil in a few years, here is what you should do:

 1.  Apply Actinovate to the planting hole when planting each tomato seedling.

 2.  A month later apply Actinovate as a drench and then again as a foliar spray.  Then repreat the drench/foliar spray routine every two to three weeks right through to first frost.  This program will almost guarantee freedom from fungal disease and root knot nematodes. 

 Fix The Garden's Soil

 When garden soil has at least 5% organic matter all year, every year, there is a enormous buildup of beneficial soil microbes that will control most fungal disease spores and root knot nematodes.  That wonderful condition takes 2 to 3 years to build up. The way you do this is to have at least 2 to 3 inches of organic mulch (like straw) over the entire garden 365 days a year for every year. 

 Understanding Tomato Health: A Beginner's Guide

 The chart is organized to give you a quick and dirty summary of the possible symptoms that you may encounter. Those problem causes for which we have full files will be linked to those files. Those causes with no link will have a paragraph below the chart helping you deal with that   particular problem.

Common Tomato Diseases Every Beginner Should Know

Curled and Twisted Because of Curly Top

Tomato seedlings infected with curly top disease show yellow, curled and puckered foliage. The disease, caused by a virus, dwarfs and kills them. Infected older tomato plants do not show obvious symptoms. Curly top cannot be cured. Remove and destroy infected and surrounding plants directly in the trash. Prevent curly top by growing resistant tomato varieties such as ‘Owyhee’ and ‘Payette’. Also, control whiteflies and leafhoppers, pests which transmit the disease.

Click here for more information about Dealing_with_Whiteflies .

Nutrient Deficiencies and Their Impact on Tomatoes

Shriveled Fruit Bottoms Caused by Blossom End Rot

Blossom end rot causes the bottoms of maturing tomatoes to become soft and watery, developing large, dark brown, leathery spots. It is caused by a calcium deficiency due to soil moisture problems. Water plants consistently and only as needed. To provide calcium quickly, use liquid lime as directed on the product label.

Blossom end rot may also result from overfertilizing, so avoid feeding plants with a nitrogen-rich fertilizer. Too much nitrogen overstimulates leaf growth at the expense of fruit set and exacerbates the calcium deficiency problem.
 

Environmental Factors Affecting Tomato Growth

Slow Ripening, Flat Flavor Results From Unusually Cool Air Temperature

Tomatoes like warm weather, so if summer temperatures are unusually cool, (average temperature 65° F or below), their fruit is slow to ripen and its flavor is flat. Cover plants with white polyspun floating row cover at dusk to retain heat overnight. Remove it in the morning when the heat of the sun returns.

Protecting Tomatoes from Sun Damage

Pale, Blistered Patches on Skin Caused by Sunscald

Sunscald is an environmental disorder. Sometimes tomato fruits are exposed to intense, direct sunshine for long periods due to loss of leaves from disease or over pruning. Soft pale spots develop on fruit skin and become discolored, possibly developing mold growth as well.

Encourage tomato plants with affected fruit to develop several stems to increase the foliage canopy by allowing some suckers to develop into secondary stems, instead of pinching them off. Attached to the plant’s support, this additional growth will not only afford some protection from sunscald, but it will also increase fruit yields.

Essential Nutrients for Healthy Tomato Plants

Pale, Yellowing Leaves Caused by Nitrogen Deficiency

Suspect a nitrogen deficiency if the leaves low on the stems of tomato plants turn yellow, dry and curl. Plants deficient in this vital nutrient grow slowly and produce small leaves. Their stems are stunted and brown, while flower buds turn pale and (drop)off. They set less fruit.

Spray plant foliage with diluted fish emulsion or other general purpose liquid fertilizer to provide a quick dose of nitrogen. Add an all-purpose slow-acting granular fertilizer to the soil around each plant if you did not do this at the beginning of the season. It will provide a steady, consistent supply of nitrogen to the tomato plants over the rest of the season.

Identifying and Managing Tomato Pests

Deformed, Yellow Leaves, Bushy Young Plants Have a Virus

Tobacco mosaic virus (TMV) causes malformed leaflets in young plants and dark green mottling (spots) on foliage. New leaflets tend to be stringy and fernlike, or pointed. Overall, affected plants look slightly grayish and their fruit may be splotchy or may ripen unevenly. Cucumber mosaic virus causes stunted, yellow, bushy plants and foliage with a characteristic shoestring appearance.

Plant viruses are incurable. Remove and destroy the infected plant, its soil and its close neighbors. Clean up debris and weeds in the planting area because viruses may also live in weedy plants such as motherwort, plantain, and pokeweed. Because TMV may also be transmitted by aphids, control them if they are on your tomato plants. Do not smoke or use tobacco products around your plants. Plant resistant tomato varieties.

Creating a Healthy Environment for Tomato Growth

Tan Scars on Deformed Fruit is Due to Environmental Stresses

“Catfacing,” a spiderweb pattern of tan colored scars on the skin of deformed fruits, is caused by environmental stresses during bloom. Low temperatures, drought, or excessive heat cause young fruit to develop more than the usual number of cells. Sometimes high winds, accidental exposure to the common herbicide 2,4-D, and heavy use of fertilizers also produce catfacing.

Control this problem by planting resistant tomato varieties such as: ‘Big Set’, ‘Burpee’s VF’, ‘Flora-Dade’, ‘Floradel’, and ‘Floramerica’.

Common Tomato Issues and How to Fix Them

Water-soaked Areas on Leaves Caused by Bacterial Spot

Bacterial spot causes minute water-soaked areas on tomato foliage. These lesions become angular, turn black and develop a greasy appearance. Green fruit develops small black, raised spots which enlarge, become irregular in shape and pitted. There is no effective treatment for bacterial spot. At the first sign of infection, pull up the plant and discard it in the trash. Wash your hands, gloves and tools to prevent the spread of the infection.

• Tomatoes Look Like They Grow Into One Another