Knowing when and how often to water your plants can sometimes feel more like an art than a science, perhaps no more so than for tomatoes. Overwatering tomatoes can lead to yellow and spotted leaves, while underwatering results in wilt and diseased fruit.
Tomatoes don't like their roots dry, so it's best to water them every day, they will also benefit from a weekly dose of liquid fertilizer.
Over-watering.
Leaves might yellow and wither, or they could curl.
Plants can also run out of water through overwatering! When a plant is over-watered, its roots rot. They can no longer drink and feed the stems and leaves. And the leaf blades curl up to reduce water evaporation.
The good news is tomato plants are resilient. Identifying the problem early limits damage and makes it easier to revive the plant. Even plants with evidence of dying roots can be rescued.
Symptoms on leaves - curling & distortion
Symptoms: upward rolling of the leaves. This is a common occurrence in mid-summer and is associated with high temperatures and moisture stress. Some tomato varieties, including heavily pruned determinate-type varieties, are more prone to leaf roll.
While underwatered foliage will be dry and crispy, overwatered tomato plants will usually have soft and mushy leaves or stems. The issue lies in root health. When you overwater, you limit the amount of airflow around the roots, essentially suffocating them.
Drip irrigation has emerged as one of the most efficient methods for irrigating tomatoes.
Sunscald. Tomato plants protect their fruit with an umbrella of leaves. In bright, hot weather, fruit exposed to the sun may develop a scalded, or sunburned, spot. This is most common on green fruit.
Avoid plants with yellowing or wilted leaves, as these may indicate nutrient deficiencies or disease. Inspect the stems for any signs of damage or discoloration, as healthy tomato plants should have strong, upright stems.
Heat and low moisture can cause the edges of the tomato leaves to die back, then twist and curl. Hot dry weather may also cause a symptom called physiological leaf roll. This is a self- defense response, where leaves and leaflets curl slightly to prevent further water loss (Fig.
A simple way of assessing water stress is to calculate what percentage of available water is being used ('use-to-availability ratio'). Specifically, blue water stress is the percentage of water used from rivers, lakes and aquifers.
The good news is that most plants will bounce back between 7-14 days if they're given proper care (which includes rehydration). If this isn't possible because major damage was done or little healthy root system exists then expect about 2 weeks until improvement can be seen.
Pruning tomatoes encourages strong growth and fruit yield. Removing dead or diseased leaves and branches will also assist in lessening the likelihood of pests or illnesses that might harm your crop. Along with trimming, be sure to water, feed, and weed-free your crops.
You probably overwatered your plant if both old and new leaves are falling off at the same time. These leaves can be green, brown, or yellow.
Leaf Curl, prevention is the only way to deal with it that I know of. I start spraying my trees with Neem oil / Bonide Copper Fungicide mixture when dormant 3 times last spray when the buds start swelling but are still gray colored. Blossom Blight is a problem too, this spray takes care of that too.
Nitrogen causes stem growth as well as dark green leaf color. Adding only an iron fertilizer or chelate causes the new growth to become green but does not stimulate new growth that much. When iron is involved, the yellowing occurs on newer growth. Yellowing due to a need for nitrogen occurs all over the plant.