The tomato plants have developed magnificently, are growing excellently, forming numerous flowers and then – fruits. But then the nasty surprise – the tomatoes get black spots. But why do tomatoes actually rot on the bush? We list 4 early symptoms of brown rot and explain how you can still save the plants.
Why do tomatoes rot on the bush?
Unlike other diseases, brown rot is not caused by pathogens. Unfavorable weather conditions in combination with some common mistakes in care lead to calcium deficiency.
The fruits rot from below because of drought
Tomatoes are particularly sensitive to prolonged periods of heat and lack of water. They cannot absorb enough moisture through the roots. Since the nutrients are transported with the irrigation water, a lack of water can quickly lead to a lack of nutrients. Tomatoes only get very small amounts of calcium and this is transported to the leaves first. A calcium deficiency is therefore first noticeable in the fruits, because they are the first to be undersupplied.
Soil analysis often reveals normal soil calcium levels during drought. The problem can be solved by giving plenty of water when it is dry. So that the soil can absorb the irrigation water better, the plants should be watered from below, early in the morning and very slowly.
What won’t help is the extra calcium supplements. While antacid tablets, egg shells, etc. can increase calcium levels in the soil, the plant will not be able to absorb the nutrient without water.
Tomatoes have a lot of little rotten spots: clay soil
If the soil is moderately moist but the tomatoes are still developing small brown spots, then the problem is with the soil conditions. Clay soil is sticky and makes it difficult for the soil to absorb nutrients. Certain fertilizers, such as coffee grounds, can complicate the situation – coffee in large quantities can form an impermeable layer in the soil, leading to waterlogging and nutrient deficiencies.
To avoid this, the clay soil should be loosened regularly. An extra layer of sand can improve drainage. You should also be very careful with fertilizing – and find out what one or the other home remedy can do.
In addition, with loamy soil, the irrigation water needs more time to seep into the soil. Therefore, you should water carefully and slowly.
Rotting Tomatoes: Damaged roots
When the weather changes, the roots of heavy feeders suffer the most. They constantly have to adapt and regulate the water content of the plant depending on whether it’s raining heavily or the sun is shining today. Alternating drought and waterlogging can lead to root rot. Then the plant cannot absorb the nutrients and the fruits are the first to rot. In addition, weakened tomatoes often fall victim to various fungal diseases. Fruits dry much slower than leaves and can rot.
That is why the tomatoes absolutely need rain protection. They are also best protected from the wind so that the shoots do not break in a storm and the fruits are damaged.
Another common mistake is to loosen the soil in the root area and work in fertilizer when it is dry. The inexperienced hobby gardener can accidentally damage the sensitive roots.
Instead, a finger-thick layer of mulch can help keep the soil moist but not wet. Lawn clippings are best, as they protect the soil from drying out and at the same time provide nutrients.
Tomatoes turn black: over-fertilization
Tomatoes are often over-fertilized. On the one hand, because they are often supplied with the wrong fertilizers. On the other hand, because they get too much of a good thing.
Fast-dissolving mineral-based fertilizers or fertilizers with a high nitrogen content in particular can damage tomatoes during the flowering or harvesting season. The consequences go unnoticed at first – the roots burn and the leaves turn brown from bottom to top. The new leaves and flowers wilt first, and then the old ones. The end result is severe leaf loss. The fruits first get many small brown spots, which then gradually get bigger.
A good variant of natural fertilizer is worm tea. This is a self-made liquid fertilizer made from organic waste that has been decomposed by worms. Various manures such as nettle manure can also promote fruit formation and shorten the ripening period.
Tomatoes wither quickly on the bush?
Tomatoes planted near walnut trees will wither quickly and bear little fruit. The walnut trees secrete a chemical that is toxic to other plants and can stunt their growth. In this case, there is only one thing left – to plant the tomatoes in a raised bed or in a greenhouse and fill the bed with potting soil.
Tomatoes rot on the bush: tips for prevention
There are a few basic rules for tomato care and those who follow them can look forward to healthy plants and a rich harvest.
1. Tomatoes need a sunny spot. Choose a spot where they can get at least eight hours of direct sunlight per day.
2. Check the soil for waterlogging and improve if necessary. Normal garden soil crumbles when dry and clumps when wet.
3. Water the plants generously when it is not raining. Water the tomatoes from below and slowly so that the soil can absorb the water.
4. Fertilize the plants with a suitable natural fertilizer. You can first work compost into the root zone and then adjust the fertilizer type to suit the needs of the plants.
5. Tie up the tomatoes. The high-bound shoots dry faster and are less susceptible to fungal diseases and bacteria.
Tomatoes are very undemanding plants. They need plenty of water, a sunny location and well-drained soil to thrive and bear numerous fruits. If you stick to a few basic rules and recognize the early symptoms of a deficiency, you will certainly bring in a rich harvest. Fertilize the heavy feeders regularly with the right fertilizer depending on the stage of development, so that you can prevent or combat a calcium deficiency.