If you’ve had or are having issues with your tomatoes, the following information and chart will be helpful. It is important to identify and treat the common ailments of tomato plants.
Blossom End Rot: This is one of the most common ailments and you can tell if your plants have it by looking at where the tomatoes are attached to the vine. If the attachment appears brown and leathery about the size of a small coin, the tomato has Blossom End Rot.
To Treat: Take all the tomatoes off the plants that are affected and dispose of them. Calcium is required in relatively large concentrations for normal cell growth. When a rapidly growing fruit is deprived of calcium, the tissues break down leaving the characteristic lesion at the blossom end. Blossom end rot develops when the fruit's demand for calcium exceeds the supply in the soil.
This may result from low calcium levels in the soil, drought stress, excessive soil moisture, and/or fluctuations due to rain or over watering. Lime (unless the soil is already alkaline), composted manures or bone meal will supply calcium.
Blight: There are three stages of Blight. Early Blight is black and grey spots on the leaves when the tomatoes are young. Southern Blight is black and grey spots by the stem and roots of the tomato plant. Late Blight gets out of hand and is black and grey spots throughout the leaves, vines, and tomatoes.
To Treat: The easiest way is to treat it in its early stages by removing the parts of the tomato plants that are infected. If you don't notice until the later stages of Blight, you will need to buy an anti-fungal treatment.
Caterpillars: They love to feed on tomato plants and should be taken care of right away.
To Treat: There are many treatments available at your local garden centre to fight against caterpillar infestations. Safe organic remedies with an Apple Cider Vinegar spray will keep them away. You can also plant Marigolds to help deter them.
Fruit Splitting: This can occur when it is dry followed by heavy rains, or most frequently when there is a sudden growth in the tomato plant. The effect is cosmetic only.
To Treat: If it occurs early in the tomato plant’s growth, it can be reversed. Just water and apply nutrients as normal. If it happens near harvest, it can't be reversed.
Red Spider Mites: They are hard to spot and are usually under the leaves. If you notice cobwebs on your tomato plants, then you definitely have them.
To Treat: You can buy treatments at the garden centre but making your own organic Apple Cider Vinegar spray, soap spray, or Onion and Garlic spray is an easy solution. Planting Coriander, Dill, and Chrysanthemums are good ways to deter them.
Wilt: This is a fungal infection that starts in the roots and blocks most of the water/nutrients from getting to the plant. It usually does not cause a problem until the tomatoes are growing on the vines. First is a yellowing and drying of lower leaves and then the whole plant will wilt during the hottest period of day. It will recover slightly at night, but wilt again the next day.
To Treat: There is no treatment when you get Wilt since it is in the soil. Therefore the next time you grow tomatoes, pick a different spot in the garden to grow them. It will deprive the Wilt of a host, and it will die out over the next year. Grow seedlings inside in clean soil before transplanting in Spring, making sure to pull out all weeds that appear around them.
Sun Scorch: The skin of the tomatoes will look bruised and sunken.
To Treat: Do not prune the leaves during hot periods. The extra leaves will shield the tomatoes. Use shade cloth to cover them during these periods. Once they get Sun Scorch, nothing can be done for the affected fruit but shade can be provided for the unaffected fruit.