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Common Growing Problems

The Most Common Problems With Tomato Plants

There are a variety of diseases, pests and problems that every tomato gardener should learn to recognize in order to determine the best preventative and remedy for your tomato plants:

Firstly, identify the affected part of the tomato plant that has the problem: (roots, leaves, stems, blossoms or the fruit.) Then compare the ailing plant with a healthy tomato plant. Healthy tomato plants look healthy. Healthy tomato plants should display soft, leaves with medium to dark shades of green with solid stems. Leaves that are yellow, or pale, or exhibit dark or ragged patches or edges, or show signs of spotting or mildew are indicative of a problem.

Preventing plant problems is far better than trying to rescue a plant from a problem.

  • Provide adequate fertilizer that nourishes a plant with sufficient organic matter. Apply your fertilizer carefully and according to instructions given throughout the life of the plant.
  • Don't over fertilize. I've seen this often from over-anxious gardeners. Over fertilizing can actually work against your seedlings. This may cause them to stop growing, to grow too rapidly into spindly plants, or even die. One or two applications of very dilute fertilizer are plenty to get a seedling growing to transplant size.
  • Damping Off is characterized by a lack of germination or a narrowing of the newly emerged tiny seedlings at the soil line that flop over and die. Various soil fungi are responsible for this condition that are found in any seed starting mix that contains real soil. Also, can be caused by having the plastic that covers your new seedlings tight enough to not permit airflow.
  • "Leggy," seedlings means the stems are elongated and limp, flimsy with sparse foliage. Leggy seedlings usually occur with insufficient or indirect lighting, too much heat, or too much fertilizer. If this occurs for you I suggest you consider repotting the seedlings deeper in your pot, use a fan to improve air circulation and keep temperatures slightly cooler for stockier and hardier plants.
  • Slow growth: Have patience. When seedlings seem to be taking forever to grow, it is usually due to low temperatures or inadequate nutrition. Over-watering: Many growers harm their tomato plants by over-watering. Soggy soil may cause your tomato seeds to rot. Once the seedlings have started, they should be watered thoroughly then left un-watered to dry until they are almost ready to wilt, then water them again.
  • Don't over-prune stems or leaves from your tomato plant. Tomato plants require an adequate leaf canopy to protect the fruit from being scalded by the sun and the plant needs sufficient amount of leaves for adequate photosynthesis.
  • Don't plant your tomato plants too early. Research the best time for planting in you hardiness zone.
  • Provide sufficient calcium to your tomato plants for healthier plants and better tasting fruit. You should test your soil to maintain a PH level of 6.5. You can add lime or gypsum to increase levels.
  • Water your plant responsibly. Provide even and deep watering to encourage root development. If you provide your plants too much water you may suffer root rot. Insufficient watering will result in a weak plant and inferior, dry fruit.
  • Avoid overhead watering or getting the leaves wet which can promote disease. It is best to ground-water your plants and avoid splashing lower leaves with wet dirt. It is best to use a soaker hose to saturate the ground.
  • Provide your plants sufficient air circulation. Plant your plants with enough space between the plants to allow for sufficient air circulation. Not providing enough air flow around your tomato plant will encourage a fungal growth.

Blossom End Rot

Blossom-end rot shows up as dark patch on the bottom of the fruit. This is generally caused by not providing enough calcium to the plant or the PH level in the soil is too low which prevents the plant from absorbing the calcium. Poor watering practices or periods of dry weather may worsen the problem. Many folks add crushed eggshells to their soil as a natural source of calcium.

Blossom Drop

A condition that occurs when plants produce flowers that drop off before developing into fruit. This condition most often occurs when temperatures fluctuate dramatically. Your tomato plants prefer temps that range between 55-75 degrees F. Other contributors to blossom drop are giving your plant too much nitrogen or too little water.

Fruit Cracking

Fruit cracks generally caused by poor watering methods or heavy rain following a period of hot dry weather which invites the plant to take in water fast, causing the fruit to swell and then crack. Even watering at every stage of the plants growth will lessen the chance of fruit cracking. Cracking usually appears as concentric circles on the fruit.


Sunscald of fruit affects healthy plants with plump, ripe fruit when there is insufficient leaf canopy for shading and exposure to the sun invites the fruit to scald, resulting in unattractive white areas on the skin. This also adversely diminishes the flavor of the fruit.

Insufficient Fruit Set

This problem can occur when plants produce some flowers and very few tomatoes, and is caused by too much nitrogen supplied to the tomato plant resulting in a heavily leafed plant with too little nourishment for fruiting.

Leaf Roll

Leaf Roll can happen to even healthy plants and is revealed when the leaves curl up from the outer edges toward the center and is generally caused by excessively wet soil and/or insufficient drainage.

Pricking Out Tomato Seedlings – The Complete Guide

To successfully grow tomatoes from seedings, understanding when and how to go about pricking out tomato seedlings is important. Getting your timings right and following the correct procedures can help make sure that your tomato plants grow well and provide an abundant harvest of fruit later in the growing season. Read more...