It is that time in the growing season when we sometimes see major issues with tomatoes. There are numerous causes of problems with tomatoes. I will try to give some information on a few of the more common issues.
Not enough fertilizer
Over- pruning plant
Not enough calcium
Too much or too little water
Lack of air flow around plants.
If your plant appears healthy, but as your tomatoes ripen they develop an ugly black patch on their bottoms, you have blossom end rot. This can be caused by a lack of calcium in your soil. At this point, you need to get a higher level of calcium into your plant. You can try putting a slurry of pelleted lime and water on your tomatoes. Add a couple of handsful of pelleted lime and mix with a gallon of water. Pour about 16 oz. on your tomato plant. A simpler fix is to get a foliar spray (available at any nursery) containing calcium chloride and apply early in morning or late in day to avoid burning the plant. There are several good organic versions of this spray.
Another major enemy of tomatoes can be weather. One issue caused by weather is blossom drop, which can be caused by extreme temperature fluctuations. You can’t control the temperature but you can lessen the problems by making sure tomatoes stay healthy by fertilizing regularly, planting your tomatoes around flowers that attract pollinators and using a neem oil insecticide. Fruit cracks appear on ripe tomatoes and are likely to occur when hot, rainy weather is present. Fruits dry out and then when they take on water too quickly they can suffer cracks. Again, the best way to control this problem is to try not to let tomatoes dry out too much during dry times so when rainy times occur the plants won’t take on too much of the water rapidly. Catfacing makes tomatoes appear deformed. This is caused by cool temperatures if tomatoes were planted too early.
Leaf roll will make your plants ugly but not affect tomato development. Avoid over pruning tomatoes and make sure that soil drains excess water away. If you find brown spots on your tomato leaves causing leaves to turn yellow and eventually fall off, they have early blight, a fungus that can live in the soil over winter. To avoid this, make sure to rotate your tomatoes every year. You can use a garden fungicide to help many of the diseases that cause the leaves to discolor on your tomatoes.
Any questions or suggestions? Let me know at firstname.lastname@example.org. Until next time keep your fingers in the dirt and keep on playing.
Julie Kuehl is a Polk County Master Gardener. She can be reached at email@example.com.