Even beautiful tomato bushes can one day become covered with dark spots. Many gardeners ask themselves the following question when tomatoes turn black: what to do? To solve a problem, you first need to find out the cause of its occurrence.
Most often, tomatoes begin to turn black due to fungal diseases. Not only the fruits are covered with spots - the leaves of tomatoes turn black (when grown in greenhouse conditions). Plaque may also appear on the leaves, which causes rotting.
As a rule, the cause of the disease is high air humidity in the environment where tomato bushes grow. In July and August, the night temperature is quite low for these plants, and therefore they become vulnerable to various types of diseases. Fungal spores accumulate in the ground and are able to quickly and easily move to various plant crops.
The main reason - late blight - manifests itself as follows: tomato leaves turn black. A sharp difference between day and night ambient temperatures causes this disease. To eliminate it in a timely manner, you need to monitor the appearance of the foliage. Inexperienced gardeners often notice this disease only at the stage when the fruit itself has already turned black. But tomatoes in the greenhouse turn black starting from the leaves. Therefore, it is important to inspect the foliage for brown and dark spots.
If you see gray spotting, this also indicates the presence of a fungal disease. The fruits become covered with gray spots, the tomatoes gradually turn black as the pathology develops. Over time, rot covers the entire plant. Hence the name of this disease - gray rot.
There are cases when tomatoes turn black due to a lack of calcium in the soil. Overly acidic soil is also a common cause. If the balance of microelements is disturbed, the tomato yield decreases.
Experienced gardeners and gardeners understand why tomatoes turn black and know what to do to fix the problem. The most common causes, in addition to fusarium, include cladosporiosis and macrosporiosis. When the fungus gets on the bush, the spores spread quite quickly. It takes them from a week to 30 days to spread and infect the entire bush.
In some cases, tomatoes become stained after harvest. As a result, such fruits become unusable. Anthracnose is considered the most common cause of this phenomenon. If fungal spores have reached the fruit, their effect may appear on the appearance of the tomatoes later (even after harvest). The spores gradually destroy the fruit. But this only occurs when grown in open ground. Tomatoes turn black in a greenhouse due to fusarium blight.
As you can see, there are several answers to why the leaves of tomatoes in a greenhouse turn black. And the first thing you need to do to save them is to correctly determine the cause.
How to save fruits
Having learned why the leaves of tomatoes in a greenhouse turn black, it is important to apply an appropriate method to combat this phenomenon. If the reason is an excess or lack of mineral fertilizers, it is enough to simply restore their balance in the soil. If the reason lies in high acidity, add wood ash to the soil. Dolomite flour is also suitable for these purposes.
If the cause is a fungal infection, this disease can be eliminated with the help of fungicides. Since tomatoes are grown for human consumption, you should be extremely careful when using such drugs. It is important to minimize exposure to substances harmful to the human body. Therefore, regularly inspect the bushes and do not allow the beds to become too dense.
Remove the affected parts and spray the bushes with Bordeaux mixture. Calcium chloride will also work. Tomatoes do not absorb these compounds. Another option is to use the salt water spray method. It will cover the surface of the bushes with a kind of “shield” that will not allow spores through and will prevent their further reproduction on plants.
There are also folk methods that are used to prevent tomatoes from turning black in a greenhouse. For example, some use garlic infusion for these purposes. Lactic acid can also prevent the spread of spores. Regardless of the spraying composition chosen, this work is best done on a cloudy day.
To increase the resistance of bushes to such diseases, it is recommended to use copper sulfate. Some gardeners pierce the stem with copper wire at a height of about 10 cm from the soil surface. All juices that rise above this mark are enriched with copper ions. This “injection” perfectly protects against fungus.
It is also worth noting that fungal spores accumulate in the upper layers of the soil. Therefore, it is necessary to follow the basic rules of crop rotation. Do not grow tomatoes for more than 3 years in one area. Do not plant these crops near peppers or eggplants. Carefully dig up the soil around the bushes.
Effective prevention
To prevent blackening of tomatoes and leaves, it is important to properly prepare the seeds. In addition, before planting you need to dig up the area. Sometimes it is even necessary to replace the top layer of soil.
Don't overdo it with fertilizers. Do not apply manure as it is not good for tomatoes. Treat the seeds with a solution of potassium permanganate. It is important to disinfect them, regardless of the chosen variety. Change the planting site every 3 years.
Avoid high humidity and do not plant tomatoes in shaded areas. Watering should be done so that moisture does not come into contact with the foliage and stem. After rains, it is necessary to loosen the soil to ensure air access to the root system of plants.
Video “How to protect tomatoes from late blight”
From this video you will learn how to protect tomatoes from late blight disease.
Gardeners are often interested in why tomatoes turn black. A good harvest is the dream of any gardener, but sometimes it happens that plants are exposed to various negative factors. In general, this phenomenon is observed quite often in tomatoes. It manifests itself in different ways: both leaves and fruits may turn black. Typically, tomatoes darken in early August, when they are still green, that is, at the ripening stage. Those who have encountered this phenomenon for the first time are interested in what its causes are and what needs to be done to prevent tomatoes from turning black.
Let's figure out why tomatoes turn black. There are several reasons that can cause tomatoes to turn black. Most often this occurs due to the plant being damaged by late blight. With this disease, the trunks and leaves are first affected. The leaves on the inside are covered with a gray coating, and on the outside they become brown and spotted.
At first glance, it seems that the fruits remain untouched by the disease, but this is not the case. Later, when ripe, they will become covered with blackening spots, and the pulp inside will begin to rot. Fruits that have turned black will have to be thrown away, as they are forbidden to be eaten.
Phytophthora loves high humidity, so during the rainy season it spreads especially quickly, damaging fruits at any stage of ripening.
Naturally, gardeners are interested in what to do to avoid infection of the plant with this disease. Firstly, it is recommended to water tomatoes at the roots in July and August, avoiding moisture getting on the foliage and fruits. If late blight has already affected the bushes, then the infected parts of the plant need to be gotten rid of as soon as possible. Thinning the bushes will create additional ventilation, which helps in the fight against late blight.
For preventive purposes, it is recommended to treat tomato bushes with lightly salted water.
If symptoms of infection have already appeared on the fruits or leaves, then you can spray the tomatoes with 1% Bordeaux solution (a mixture of milk of lime and copper sulfate solution). But this remedy is effective only at the initial stage of infection.
In order to prevent tomato diseases, it is recommended not to plant them in the same beds, and if you do this, then only with an interval of 4 years. Another tip: do not plant tomatoes in the same beds where potatoes or peppers were grown.
Considering that late blight does not tolerate intense sunlight, well-lit and ventilated places are best suited for growing tomatoes. It is advisable to maintain a distance of 30 cm or more between the soil and foliage to ensure good air circulation.
If you grow early varieties of tomatoes, then the bulk of the harvest can be harvested before late blight begins to actively develop.
Other reasons for darkening of tomatoes
Another disease that affects tomatoes and leads to blackening of the fruit is apical, or gray, rot. The factor that provokes the development of this disease is a lack of any mineral substances, most often calcium. Other reasons include high temperature and low humidity.
The disease affects still green fruits. First, a grayish spot appears, which darkens over time and is easily separated from the healthy pulp. Rot spreads quite quickly, attracting many bacteria and fungi, which accelerates the process of rotting of the fruit.
Let's figure out why tomatoes turn black in a greenhouse. There, due to too dry air, they are attacked by the same gray rot. To prevent this, tomatoes in a greenhouse in the initial stage of ripening need to be watered at least once every 2 days, and in hot weather - daily. When applying fertilizers, it is recommended to moisten the soil so as not to burn the roots of the plant.
The appearance of blossom end rot can also be caused by excessive use of nitrogen fertilizers.
Tomatoes also turn black due to increased acidity of the soil, so it is better to add lime, wood ash or crushed chalk to the soil before planting.
To prevent crop loss, it is necessary to pay close attention to the plants and take action immediately when the first symptoms of disease appear. Nothing can be done about blackened fruits - they must be quickly removed along with diseased leaves.
To grow tomatoes, you need to put in a lot of effort from the very beginning: choose the right seeds, germinate seedlings from them, plant seedlings in the ground, water and feed the plants. And then one day, when it would seem that all that remains is to harvest, you suddenly discover that the tomato bushes have begun to dry out, and the still unripe fruits themselves have turned black. How does this happen? Why do green tomatoes turn black in open ground and in a greenhouse, at what temperature does this happen?
There may be several reasons for this. This may be or, which occurs when there is a deficiency of certain minerals, in particular calcium. In addition, tomatoes turn black on the bushes due to increased acidity of the soil. You may have overfed your plants with fertilizers containing nitrogen. But most often, tomatoes turn black when infected - a fungal disease that spreads to some vegetables, including potatoes.
Late blight develops especially quickly in rainy, damp weather. Initially, the disease appears on tomato leaves: the upper part is covered with brown spots, and the lower part is covered with a gray coating. Gradually, the leaves of the tomato turn black, and then the green fruits begin to darken. Sometimes outwardly it may seem that late blight has not affected the fruit, but as they ripen, brown spots appear on them, the tomato rots from the inside and is no longer suitable for use.
This disease begins to spread especially quickly in July-August, when fogs appear, heavy dew falls, and the difference between day and night temperatures increases.
Measures to prevent late blight
Late blight prevention should be done long before it appears in your garden. First of all, it is necessary to observe crop rotation on your site: under no circumstances should you plant tomatoes after potatoes or next to them. In addition, it is important to maintain the optimal planting density of tomatoes, regularly weed, and remove all diseased or wilting leaves.
In order to prevent diseases, it is equally important to promptly plant and tie up bushes of tall varieties. In this case, there should be at least fifteen centimeters from the soil to the lower leaves of the plant. There will be enough air in the thinned crown, which will prevent the occurrence of fungal diseases.
You can also carry out chemical prevention of tomato late blight: after flowering, treat the tomato bushes with solutions of “Acrobat”, “Metaxyl” or “Zaslon”. Then, as the tomato bushes grow, they must be treated with a solution of any of the fungicides, which includes copper.
A widely known folk method is to pierce the stem of a tomato with copper wire at a height of approximately 15 cm from the ground. Nutrients will rise up the stem and carry copper ions, which serve as an obstacle to the development of fungal diseases.
What to do if tomatoes turn black?
If, despite all the preventive measures, the leaves on the tomatoes still dry out, and the tips of the fruits turn black below, then it is necessary to urgently begin the fight for the safety of the harvest. To do this, choose one of the cloudy days and spray the tomato bushes with a solution of calcium chloride or simply with a warm salty solution. A salt film forms on the tomato, which will protect healthy 
fruit from fungal spores.
After it has rained, spray the diseased plants with a 1% solution of Bordeaux mixture, which does not penetrate into the plants themselves, and therefore will not enter the human body.
There are many folk ways to combat late blight. You can treat tomato bushes with garlic infusion, a mixture of kefir or yogurt with water.
Cut and destroy completely damaged tomato bushes, and pick the fruits green. Before placing such tomatoes for ripening, they must be treated with hot water at temperatures up to 70°C.
What gardener is not familiar with the situation when, in the midst of fruiting, the tomatoes on the bush turn black. The first panic question: what to do? After all, the fruits have already set, the first ones are most often ripe, and you want to harvest the entire harvest healthy.
To get rid of black spots on tomatoes and choose a way to treat them, you need to figure out why this happens. And there are a lot of them, although each disease or factor has its own characteristic signs.
Why tomatoes on the bush turn black - an overview of the reasons
Black spots on tomatoes and drying leaves can appear at any stage of plant development:
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- The leaves of tomato seedlings also darken and dry out, most often due to an incorrectly selected soil mixture and errors in care;
- the trunk turned black - the seedlings got blackleg;
- the lower leaves of tomatoes turn black - sad, but this is late blight;
- the tips of the leaves and the tips of the shoots curl and turn black – Alternaria blight;
- why green tomatoes turn black, there may be several reasons: blossom end rot (tomato fruits turn black from below), gray and watery rot, bacterial cancer, anthractic blight and alternaria blight;
- dark spots appear, the leaves of the tomatoes wither, and then the tomatoes are affected by brown spot.
In greenhouses, there is another reason, characterized by blackening of tomato leaves: with poor ventilation, the plants simply do not have enough air. If breathing is impaired, the leaf blades turn black and dry, the flowers and ovaries fall off, and the bushes become infected with fungal infections.
As you can see, the tomato leaves darken and wither, the bush withers, black spots appear on the tomatoes for various reasons and therefore the methods of how to deal with this are different. We will tell you how to treat tomatoes and what to do for prevention so that the bushes and fruits do not turn black in each specific case.
What to do - chemicals and traditional methods
Having determined the reason why tomato leaves turn black, you must immediately begin treating the darkened bushes and protecting healthy plants.
Cause: late blight
You can read in detail about the symptoms and manifestations of late blight on our website. The disease begins with the appearance of gray spots, with a white coating on the lower part.
They quickly spread and darken, then the stems of the tomatoes turn black, and brown spots appear on the fruits. If left untreated, the plants die within a week or two, and the crop becomes unfit for consumption.
Folk remedies:
- spraying with garlic infusion: 1 cup of ground garlic and 1 g of potassium permanganate per bucket of water;
- whey should be diluted 1:1 and treated with infected parts of the bushes;
- treatment with milk and iodine: for 10 liters of water, take 1 liter of milk and 25 drops of iodine.
Chemicals (use according to instructions):
- Ridomil;
- Screen;
Mandatory preventive measures - it is necessary to remove and burn diseased plants, tillage, sowing green manure.
Blossom rot on tomatoes
An extremely unpleasant disease when the green fruits on the bottom of apparently healthy plants begin to turn black.
Folk remedies do not help much; at the first symptoms, you can sprinkle the bushes and soil in a greenhouse or garden bed with ash.
The most effective treatment is spraying with a solution of calcium nitrate: 4 g of the substance per 1 liter of water. And also, every 2 weeks, carry out preventive treatments of bushes and soil with the following composition: 2 g of saltpeter per 1 liter of water.
Tomato rot - gray and wet
These diseases affect bushes already at the end of the season. First, weeping spots appear on the fruits, which darken and spread throughout the entire bush, despite good care of the plants.
The fruits become unsuitable for food. It is possible to stop the development of the disease only in the first stages; what is more important is the prevention of infection - the destruction of plant debris to prevent the proliferation of fungal spores.
Tomatoes most often suffer from rot in the greenhouse, so you need to ventilate them often and water the bushes with warm water. For treatment, you can use such remedies for fungal diseases as Trichodermin, Fundazol, Bayleton, Acrobat, Skor.
Brown spot
Another fungal disease in which only the leaves of tomatoes turn black. It begins with the appearance of brown spots, covered with a dark coating below. As the fungus develops, the spots dry out, forming holes, the leaves curl, and without treatment the bush dies. For treatment, the bushes must be treated every 10 days with any copper-containing preparation according to the instructions. The disease is highly treatable.
Tomatoes often suffer from other types of spots: gray, white, bacterial, black. Only chemical treatment helps, using Bravo and Fundazol.
Macrosporiasis
An unpleasant, although rare, fungal disease of nightshade crops. Not only tomatoes, but also eggplants, physalis, and potatoes get sick in conditions of high humidity. The disease begins with the appearance of a brown spot on the lower part of ripening fruits. Then a black coating appears on it.
Then the lower leaves turn black and dry out, and light circles with a dark spot in the middle appear on the upper plates. Macrosporiasis is difficult to treat. Experts recommend cutting off all affected parts, while the instrument requires treatment with potassium permanganate so as not to spread the infection.
And then the bushes must be treated with any contact-systemic fungicide. These are Ridomil Gold, Revus Top, Pomodorchik-2, Tomato Rescuer, Prosaro.
Fomoz
This disease is associated with an excess of nitrogen fertilizers and fattening of plants. Infection begins with blackening of the stalk. The stain spreads to the green ovaries, gradually covering the entire fruit. It turns black from the inside and falls off.
Control measures - competent agricultural technology after planting seedlings in a permanent place - fertilizing no more than once every 2 weeks, normalizing nitrogen fertilizers. At the beginning of the disease, limit watering, cut off infected brushes, treat the bush with ash infusion: dilute a 1 liter jar in a bucket of water, leave for 3-4 hours, then pour over the plant.
Anthracnose
A particular disease of tomatoes that begins with damage to the roots and spreads to green fruits. Dents and dark spots with edging appear on them. The fruit inside begins to rot. At the first symptoms, all bushes should be treated with colloidal sulfur, and then with one of the fungicides: Champion or Defender.
Alternaria blight
A dangerous disease that affects the entire bush and renders the fruit unusable. Dry, brown, clearly defined spots of varying sizes appear on leaves, stems and fruits. Very quickly the leaf turns yellow and dies. The spots on the fruit become larger and the tomatoes cannot be eaten. The fungus can spread to other garden crops, as well as grapes and apple trees.
At the first stage, treatment with Trichodermin or Fitosporin helps. Copper sulfate is also effective: dilute 20 g of powder and a piece of laundry soap (shavings) in a bucket of water.
The following chemicals are effective against Alternaria:
- Quadris.
- Bravo.
- Acrobat MIYU
- Abiga Peak.
- Ridomil Gold MC.
- Champion.
- Ordan.
Bacterial cancer
This disease is not of fungal origin. The pathogens overwinter in the soil; most often, infection occurs due to poor-quality soil for seedlings. It must be sterilized before sowing.
Cancer affects the entire plant - from roots to fruits. First, ulcers appear, which enlarge and turn black. The first remedy is “Tomato Rescuer”. With the appearance of the first ulcers, you can treat with Phytoflavin or Fitosporin.
What causes picked tomatoes to turn black?
This problem is quite common, especially with tomatoes harvested in the fall and placed for ripening. There are many reasons why fruits spoil:
- poor ventilation in the room or between fruits;
- temperature below + 5 and above +15 degrees;
- high humidity, mold;
- the fruits were collected from bushes affected by anthracnose.
When infected with anthracnose, even if the fruits are outwardly completely healthy at the time of harvest, during storage dots appear on them, slightly darker than the color of the tomato. Then they turn black and grow, the fruit becomes unfit for consumption.
How do you treat blackened tomatoes? No problem, they need to be disposed of and not end up in the garden. To prevent tomatoes from turning black, during the growing season they must be treated with Strobi or Quadris according to the instructions.
Preventive measures
In the fall, you need to carefully remove the tomato tops and remove the roots from the soil. Take them out and burn them. Treat the soil with copper sulfate, sprinkle with ash and dig up. If the weather permits, sow the beds with mustard as green manure.
Or do it in early spring, as soon as it gets warm. Before planting the seedlings, the mustard will grow and need to be dug into the ground. Thanks to its phytoncides, mustard disinfects the soil, killing fungi and pathogenic bacteria.