8 Common Problems When Growing Tomatoes

Tuesday, 4 June 2019 11:18:41 Europe/London

problems with growing tomatoes

Growing tomatoes in your greenhouse or outdoors in your garden can be extremely rewarding. There are many varieties you can grow for delicious salads and other recipes. You can even beat the record for the largest tomato at 12 pounds or the Guinness World Record for the tallest hydroponically grown tomato plant at 65 feet - that’s us!

Powdery Mildew

In tomato plants, powdery mildew shows up as if someone has brushed white powder on the leaves. The stem and the leaves may present white spots, which will eventually turn yellow and brown as the disease progresses.

If you’re growing tomatoes in a greenhouse, make sure to pay attention to humidity and airflow levels. High humidity and lack or airflow are main causes of powdery mildew.


Blossom Drop

Tomato plant flowers drop without developing any tomatoes, which is typically caused when there are temperature fluctuations. 13℃ to 24℃ is the average temperature for tomato plants to keep their flowers, which tend to fall off when temperatures fluctuate outside of this range.

Too much or not enough nitrogen, insect damage, and lack of water can also cause blossom drop.


Blossom End Rot

A black patch will appear at the bottom of the tomatoes as they ripen, even if the plants seem to be healthy. These spots will look leathery and the inside mealy. This tends to happen when tomato plants don’t have enough calcium. This can either be through low calcium levels in the soil or low pH levels that don’t let the plant absorb the nutrient.

Make sure you provide your tomato plants with a balanced level of calcium, alongside consistent and even watering habits.

Read our guide on preventing and curing blossom end rot.



Bacterial Canker

Yellow dots start showing up on already ripening fruits, with a dark and bird’s-eye style rim around the dots. The bacteria Clavibacter michiganensis can enter the plants if there’s any damage like missing leaves or open sores. Crops should be rotated regularly and any infected plants immediately removed.


Poor Fruit Set

If you notice that your plants have a lot of flowers but not a lot of tomatoes, with the latter being small or tasteless, it could be a sign of too much nitrogen. When this nutrient is present in high amounts, it encourages leafy growth but not flower growth.

Another reason for poor fruit sets could be that your tomato plants are planted too closely together and wind can’t help the pollination process.


Early Blight

Older growth starts getting brown spots and rings around similar to targets. The leaves then yellow from the brown spots with leaves turning brown and falling off. The fungus Alternaria solani causes early bright; it can survive in the soil over winter and affect your tomato plants again if you’ve planted them in the same spot. Crop rotation of tomatoes, peppers, and eggplants is essential to prevent another infection.


Leaf Roll

Up to three-quarters of tomato plants can be affected by leaf roll, usually when the plants are mature. Older leaves near the bottom of the plants are more affected, which can be due to high temperatures, too much pruning, and wet soil. This won’t affect the development of the fruits, just make sure to not over-prune your plants in the future.


Fruit Cracks

Fruit cracks tend to appear in concentric circles on ripe tomatoes, which can lead to insects infiltrating the fruits. This is partly why it’s so important to water the plants evenly and consistently, as tomatoes tend to take up too much water after a dry spell. This leads them to swell up and crack. Make sure you prevent tomato plants from being too thirsty.

Get in touch with our friendly team on 0845 602 3774 to know more about growing tomatoes - we’re always happy to help!


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