tomatoesCommon Tomato Problems

From experienced gardeners to someone who just wants fresh produce grown at home, tomatoes are usually the go-to fruit to grow. Tomatoes can often be picky about their environments and are not afraid to show it. Many questions come up about "what's wrong with my tomato plant?" and the answers are often quite common. Here are some common problems that come up, how to identify them, and how you may be able to correct it: 

Blossom End Rot

Identification: While the tomato is still green, blossom end rot starts as a water-soaked looking lesion. It eventually develops into a dry, sunken decay on the bottom of the fruit.
Causes: Usually due to a stress on the plant caused by drought, excessive moisture, or fluctation of moisute from rain or overwatering.  This stress then affects the roots which will in turn affect the uptake of nutrients (and more specifically, calcium).
Solution: Adding lime, bonemeal, composted manure, or calcium supplements.

Yellowing Leaves

Identification: Yellowing of leaves on plant.
Cause: Lack of nitrogen
Solution: Add fertilizer to supplement the lack of nitrogen in the soil.
Cause: Lack of sun on the lower leaves due to the plant being big and bushy.
Solution: Do not worry about this too much, especially if there is little to no change. This is pretty normal with a lot of tomato plants.
Cause: Not enough water or too much water.
Solution: Make sure to water thoroughly once on hot days. Also provide adequate drainage to allow the plant to dry between waterings.

Blossom Drop

Identification: Plant produces blooms, then drops them before going to fruit.
Causes: Physiological stress. Temperature too high or low, lack of pollination, humidity too high or low, lack of water.
Solution: Make sure to water deeply. Try growing in an area that is easy for pollinators to find.
Cause: Too much nitrogen. This causes more leaves and less fruit.
Solution: Try to cut back on fertilizing or use a fertilizer with a low first number (fertilizers have three numbers that look like this: 10-10-10. Choose one that has the first number as the lowest).
Cause: Stress from insect damage or disease.
Solution: In a sealed container or bag bring in a sample of the plant. An expert can take a look and identify the problem. If you think you may be able to identify the pest yourself take a look at our Plant Disease or Pests pages.

Aphids

Identification: Sticky and deformed leaves. Small green, greyish, red, or black bugs on underside of leaves and/or stems.
Causes: Aphids are sap-sucking insects that deform leaves. They also leave a sticky substance called "honeydew".
Solution: Use a strong stream of water to blast them off leaves. Adding instecticidal soap to this helps as well. A homemade recipe for insecticidal soap includes: water, liquid soap, and canola oil. Also, adding beneficial insects such as ladybugs (a natural predator to aphids) will help keep aphid populations down.

Splitting or Cracking

 Identification: Splitting and/or cracking of fruit.
Causes: The insides of the fruit grow faster than the skin due to irregular water supply and/or inconsistent temperatures.
Solution: Water regularly and deeply. Adding a layer of mulch to the surface can help retain some of the moisture.

Early Blight

Identification: Spotting on leaves which eventually turn yellow and die. Small and slightly sunken dark lesions appear on stem. Spots can form on green and ripe fruit, usually beginning near the stem.
Causes: Fungal spores that can develop in moist areas.
Solution: As with any fungus, prevention is the key. Make sure room is left around the plant for good air circulation. Apply a copper spray early in the season. At the end of the season, clean up all dead plant material. Rotate crops about every 4 years.

Late Blight

Identification: Lesions form on stem. Younger leaves eventually become brown and shrivelled. The underside of leaves develop a fuzzy look. Lesions on fruit are leathery and can eventually cover the entire thing.
Cause: Fungus that is pre-existing in the soil and/or too moist of an area.
Solution: Again, the best solution to a fungus problem in prevention. Choose a warm, sunny area with plenty of air circulation around the plant. Using raised beds or containers create a warm, dry environment for tomatoes. Rotate your crops about every 4 years. When watering, make sure to use a light shower of water to avoid splashing soil up onto leaves. Also water right at the base of the plant rather than over the foliage. If plants develop signs of late blight, remove and put in sealed plastic and throw away. Do not compost it!

Fusarium and Verticillium

Identification: (Fusarium) Oldest leaves yellow and wilt, usually only on one side of the stem. Yellowing and wilt continue up the stem, with little or no fruit produced. (Verticillium) Older leaves also yellow and wilt. Results in a defoliated and stunted plant. (Both) Stem remains hard but cutting it will show browning inside.
Cause: Soil-bourne fungus.
Solution: Rotate crops every 4 years. Choose resistant varieties (marked with "VF") and if starting your own seeds, grow in clean soil. Removie and destroy any infected plant material to stop the spread.  

Flea Beetle

Identification: Tiny groups of holes in leaves- sort of resembling tiny bullet holes that go right through the leaf.
Cause: Very small black beetles that will hop from plant to plant when disturbed.
Solution: Plant trap crops such as eggplant or radishes around your tomatoes. Flea beetles are more likely to go for these crops before your tomatoes.

Leaf Roll

There are a couple of different causes of leaf roll. Pay attention to which leaves roll and which way and if there is any other damage.

Identification: Lower leaves, upward cupping, thickened and leathery. Green colour remains the same.
Cause: Physiological stress.
Solution: Check factors such as moisture, fertilizing (too much nitrogen), temperature, and pruning. Adjust any of these if need be. Transplant shock could be another factor as well. This is pretty common so do not worry about it too much; There will be minimal impact on fruit and plant growth and development.
Identification: Top leaves roll and turn pale green/yellow. Stunted growth, yellowing edges of leaves, purple veins on underside, and/or decline of fruit production.
Cause: Tomato yellow leaf curl virus.
Identification: Rolling of leaves, mottled colouring, internal browning of fruit.
Cause: Tomato mosaic virus.
Solution: There is no treatment for either TYLCV or tomato mosaic virus. Remove and destroy plants if they become infected. Prevention of these two viruses is key. Keep weeds around your tomatoes at a minimum and disinfect any tools you use. Choose resistant varieties.

 Darkened Leaves

Identification: Leaves of tomato plants start turning purple/black.
Cause: Lack of phosphourous available for the plant to use because temperatures are too cool.
Solution: Try not to plant tomatoes outdoors too early in the growing season. Use mulch around your plant to help keep warmth in the soil around the roots.