Why are tomato plant leaves yellow
7 Reasons Your Tomato Leaves Are Turning Yellow & How To Fix It
Yellowing leaves tend to induce panic in tomato gardeners.
A plant previously in good health turning from green to yellow causes alarm and results in frantic fixes that may do more harm than good.
However, yellow leaves on tomato plants are an incredibly common problem that countless tomato gardeners come across at some time over the growing period.
Most often, the problem is an easy fix (like incorrect watering), or may not even be cause for alarm at all.
These seven issues are the most common reasons for tomato leaves turning yellow. Identify the problem (if there is one at all), apply the fix, and your plants will be back to normal in no time.
1. The Seed Leaves Are Turning Yellow
Okay, let’s just cover this one first as it’s one of the most common worries for new tomato growers and shouldn’t be a worry at all.
If the leaves below are turning yellow on your young tomato plants or seedlings, do not worry.
These are the seed leaves (also called cotyledons). They are the first leaves to form when the seeds germinate but are not “true” leaves.
It is part of the development process that these leaves turn yellow and fall off and is absolutely noting to worry about.
2. Watering Problems
The Cause
The most probable cause of yellowing leaves on tomato plants is incorrect watering. Watering is a practice many gardeners get wrong – sometimes by providing the plant with too little water, but often by providing too much.
Take a look at our total guide to watering tomato plants here.
In our efforts to keep the plants happy, gardeners may overdo it on the care front and give the plant far more water than it really needs in fear that the soil will dry out. The excess water in the soil can suffocate the roots and cause them to rot. As the roots are damaged and there is less oxygen in the soil, there is less oxygen available to the leaves, causing them to turn yellow and drop off.
Underwatering can also cause the leaves to turn yellow after wilting. If underwatering is the problem, the leaves will begin to yellow from the edges, until the entire leaf drops off the plant.
The Fix
You will likely know if watering is the culprit by assessing your watering habits. If you have watered when the top layer of soil is still wet, or if the soil has become waterlogged, overwatering is likely the cause. If the leaves are wilting and the plant is struggling to stand upright (or if you know you’ve forgotten a watering session or two), underwatering is your culprit.
Correct watering is essential to the health of your tomato plants. Check the soil every day and only water when the plant absolutely needs it – approximately when the top 1 or 2 inches of soil has dried out.
Water in the mornings to prevent any evaporation or damage to the leaves. Apply water to the soil around the roots, not to the leaves, and water slowly and deeply to completely saturate the soil and encourage deep root growth.
If overwatering is the cause and the problem does not fix itself, you may be dealing with a bad case of root rot.
Root rot in a tomato plantUnfortunately, it is very difficult to save plants at this stage. You can dig up the plant, remove the decayed sections of roots, and plant in brand new soil. However, depending on how much of the root is left, and the growth of the plant, it may be best to start from scratch.
3. Soil Compaction
The Cause
A similar problem occurs when the soil around your tomato plants has inadequate aeration. The roots do not have access to enough oxygen and begin to suffocate. The roots cannot transport the oxygen, water, and other nutrients throughout the plant. This causes the leaves to turn yellow and is a sign that the plant is on its way out.
The Fix
Depending on how established the roots are, you can aerate the soil yourself by loosening it with your hands. However, this is likely to damage the root system and can cause more issues.
It is best to start the plant in good soil enriched with organic matter to avoid this problem altogether.
Soil compaction is often caused by walking on the soil, so growing tomatoes in raised beds or large pots is one way to solve the issue.
4. Transplant Shock
The Cause
If you’ve recently transplanted your seedlings (around a week or two before) and notice yellowing leaves on the bottom of the plant, transplant shock is likely the cause.
When seedlings are moved from a warm spot – indoors or a greenhouse – to cold soil outdoors, they need time to adjust to their new conditions.
The shock can cause the bottom few leaves of the plant to turn yellow. Luckily, this is just a short phase of adjustment. As long as the new growth is green and healthy, there is no cause for alarm. The yellow leaves will eventually drop off and the plant will return to good health.
The Fix
As transplant shock is not usually detrimental to the plant, and not necessarily fixable once it is discovered, it’s best to prevent the problem instead.
Before transplanting, ensure the soil has warmed and that night temperatures don’t drop too low (below 50F).
If you discover signs of transplant shock, you can aid the plant’s recovery by removing the yellowing leaves at the stem. This will direct the energy toward the much-needed new growth and away from trying to keep dying leaves going.
5. Diseases
The Cause
One of the more insidious causes of yellowing leaves is disease. Several tomato plant diseases cause yellow leaves, and many of them are difficult to tackle once established.
The first culprit is early blight, caused by a fungus in the soil. Luckily, this problem is easy to spot. In the lower leaves, a pale-yellow spot will appear, turning into a dark brown patch with yellow at the edges. If left untreated, the entire leaf will turn yellow and drop off.
A sign of early blight in tomato plants.Similar markings appear due to another fungal disease, Septoria leaf spot. Tomato plants affected by this fungus will display large brown spots in their leaves, connected by patches of yellow.
Untreated, the problem can move from the leaves to the stem of the plant and cause even more damage.
Then there are the various ‘wilts’ – Fusarium wilt, Verticillium wilt, and Bacterial wilt.
Fusarium wilt begins in the soil and infects the plant’s roots, preventing the transportation of water to the stems and leaves of the plant. The plant will appear wilted, even though there is enough water in the soil, and the leaves will begin to drop off the plant from the bottom up.
Signs of Verticillium wilt are similar to early blight and Septoria leaf spot. On the lower leaves, pale yellow spots begin to develop, surrounded by brown veins. These spots will eventually turn brown and the leaves will fall off the plant.
Less common is Bacterial wilt, caused by a bacterium commonly found in sandy soils when they are moist. This disease typically begins upon transplanting but doesn’t develop signs until later into the season. The leaves turn yellow suddenly and the plant will start to wilt.
The Fix
Any signs of disease in your tomato plants require immediate action. If left untreated, the problem can spread to the rest of your plant, and to other parts of your garden.
Early blight and Septoria leaf spot can be managed if discovered early. Remove the affected leaves and discard them, keeping them away from other plants in your garden. Apply a fungicide designed to treat the issue, following the instructions on the product exactly until the problem improves.
Unfortunately, if you encounter any of the three ‘wilts’, you will have to discard the plant immediately. There is no cure for any of these diseases, and they will spread around your garden if they get the opportunity. When removing the affected plant, ensure it does not come into contact with any other plants to avoid spread.
While there is no guaranteed way to prevent problems with diseases, there are measures you can take to limit your risk. Choose varieties with greater resistance to these diseases and give each plant enough space so the leaves do not touch.
Clean your gardening tools regularly and practice crop rotation for good soil health.
6. Nutrient Deficiency
The Cause
If none of the previous problems explain your yellowing leaves, you may be dealing with a nutrient deficiency. This could either be the result of a lack of a certain macro or micronutrient in the soil, or a problem with the plant’s ability to absorb that nutrient.
The main macronutrient culprit of yellowing leaves is nitrogen.
Nitrogen is essential for a plant’s healthy growth and leaf production. When the plant does not receive enough nitrogen, the older leaves will begin to turn a pale yellow. If you notice the plant stops growing after this period, lack of nitrogen is your answer.
A lack of certain micronutrients can also cause the leaves to yellow as a result of a condition called chlorosis. When the tomato plant lacks access to micronutrients essential to photosynthesis – magnesium, iron, sulfur, or zinc – it cannot produce chlorophyll.
This causes the leaves to turn yellow, while the veins remain bright green.
The Fix
If you suspect nutrient deficiency is the problem, apply a general fertilizer. Most all-purpose fertilizers will have a balance of nutrients to offset any deficiency in the soil.
To be certain, it is best to conduct a soil test. This will confirm the origin of the problem and allow you to fix it with a targeted solution.
For example, magnesium deficiency can be combatted by the application of an Epsom salt mixture on the leaves. Without a soil test, you cannot be certain of a deficiency and may end up damaging the plant further by applying fixes that are not necessary.
A soil test will also confirm whether the soil is the problem, or whether the plant is the problem. Remember, nutrient deficiency in a plant is not always caused by a problem with the soil. There may be an issue with the roots of the plant that cannot transport nutrients throughout the plant, rather than a problem with the soil specifically.
If the soil test confirms no deficiency in the soil, examine your watering habits and the aeration in the soil to fix the problem.
7. It’s The End of the Season
Before running through any of these scenarios and applying a million fixes, examine the time of year.
Is the tomato season ending? If so, yellowing leaves are no cause for alarm. Rather, they are a part of the plant’s natural lifecycle, signaling production is coming to an end.
Once the leaves start to drop off, you can trim any new growth and dying leaves to encouraging the ripening of the final fruits on the plant.
The first rule of any gardening fix is – don’t panic.
Based on the signs mentioned here, your analysis of the plant, and your care routine, you will probably know which problem is the most likely one.
When attempting to fix problems with yellowing leaves, always take it slow to allow the plant time to adjust before you move on to another fix. That is, unless the problem is disease-related, in which case you’ll need to act immediately (but luckily diseases are generally easier to identify).
It is a game of trial and error. If one fix doesn’t work, gradually move onto another until the plant returns to normal. In no time, you’ll have the diagnosis skills of a successful plant doctor and will be able to fix tomato plant problems with ease.
Why are my tomato leaves turning yellow?
As a tomato plant grows, it is often thought that it is in the plant’s nature for the lower leaves to turn yellow and die off. However, that is simply not true according to Joe Masabni, Ph.D., Texas A&M AgriLife Extension Service vegetable specialist in Dallas.
Yellowing leaves on tomato plants can be caused by multiple issues. (Texas A&M AgriLife photo)Masabni, an assistant professor in the Department of Horticulture in Texas A&M University’s College of Agriculture and Life Sciences, explains that a healthy plant that is well maintained and not stressed by disease or nutrition should have green leaves from the bottom to the top.
Typically, yellowing leaves are a result of a nutritional imbalance or disease outbreak, but other causes can play a part.
Nutrition can be a cause for yellowing leaves on tomato plants
“Nitrogen is the most common cause, because people generally don’t fertilize tomatoes enough,” Masabni said.
Tomatoes are heavy feeders, meaning the plant requires twice the amount of fertilizer that a cucumber needs, and even four times the amount as beans, he explained.
If you don’t fertilize enough with nitrogen, the older leaves will begin turning yellow and, in many cases, may fall off. The older leaves turn yellow because they are providing their nitrogen to the younger leaves to survive.
Yellowing of leaves can also be the result of an iron deficiency in the plant, but this will be most prominent in the youngest leaves. A magnesium deficiency however will produce yellowing that looks more like speckles or spots on the older leaves.
“Those three – nitrogen, iron and magnesium – are the most common nutritional deficiencies growers should pay attention to and fertilize regularly for,” Masabni said.
It is good to keep in mind, that with the use of a lot of fertilizer, the plant will also require a lot of water.
“There is no perfect recipe for how much water your tomato may need, but a good rule of thumb is to do a moisture test where you place a finger several inches deep in the soil to test for moisture near the roots,” he said. “If it feels dry, it’s time to water, and as the tomato plants get closer to full maturity, they will require more and more water. Better yet, buy a soil moisture meter and use it regularly as a guide on when to water.”
Diseases may present with yellow leaves
Leaf symptoms of early blight are large irregular patches of black, necrotic tissue surrounded by larger yellow areas. (Photo courtesy of Aggie Horticulture)Texas is a prime location for fungal diseases in tomatoes, simply due to the heat and humidity that are common in the state. Because these conditions are ideal for spreading diseases, Masabni suggests using a fungicide protectant on a regular basis, once every seven to 10 days, and up to 14 days in a dry year.
“Spray on a schedule whether you think you need it or not,” he said.
Fungicides are typically used as protective and not as a curative measure for fungus. So, this is a proactive approach that gardeners will want to start before seeing signs of disease to protect the plants from developing one. Once you can see the disease, it is often too late.
Powdery mildew is first noticed on older leaves as a yellow spotted appearance, that upon closer inspection has a whitish-gray powder on the surface.Most fungal and bacterial diseases cause some kind of yellowing, he explained.
The most common fungal disease seen in Texas is powdery mildew or early blight, which starts from the bottom of the plant and moves up as the leaves die off.
Physiological disorders can produce yellowing of the leaf
Salt damage – not just table salt or sodium chloride, but any excess mineral – can result in yellowing.
If you are growing tomatoes in a container and your water contains a heavy amount of salt, once in a while water the container until it leaches out, so the salt can run through the soil and flush out of the container.
This will help in preventing buildup of those salts within the container itself.
Use caution with herbicides
“Gardeners should avoid Roundup near the vegetable garden because tomatoes are super sensitive to Roundup,” Masabni said.
Roundup injury to tomatoes creates a bleaching effect from the inside to the outside of the leaf and affects the newest growth of the plant such as the youngest leaves and shoots.
Vegetable problem solver and maintenance
On the Aggie Horticulture website, the vegetable resources link provides a vegetable problem solver where you can look at different common problems you may encounter in Texas.
“The bottom line—any form of yellowing is not good,” he said.
Even if you don’t know the cause, remove any yellow leaf and throw it away in case it is diseased so it will not spread and infect others. Remove that leaf, spray a fungicide and hopefully the problem will be resolved by early diagnosis. When removing leaves, be sure to remove them with a clean hand and properly dispose of the leaf.
Wash your hands thoroughly before you continue working on other healthy plants to avoid spreading any disease between plants.
Also, ask yourself if you have been fertilizing regularly. Does the plant look tall enough or is it the same height as a month ago, which may mean you need more fertilizer?
Placing a fertilizer solution on the end of your hose and washing off your plant from top to bottom on occasion will also simulate a rainfall situation, he explained. This will be especially helpful in a dry year, when mites may become a bigger issue. Washing the plant with water will wash off the mites, and clean and cool the plant, all while fertilizing it.
For more information on vegetables and gardening resources, visit the Aggie Horticulture website.
-30-
Why the leaves of tomatoes turn yellow in the greenhouse and open field
We tell you what to do if the leaves of tomatoes turn yellow and dry, and what is the reason for the unhealthy plants.
Why do yellow spots form on tomato leaves? Does it matter on which leaves - upper or lower - they appear? How to process tomatoes if the leaves began to turn yellow? Read about all this in our article.
Why the leaves of tomatoes turn yellow in a greenhouse and greenhouse
If you notice that the lower leaves of your tomatoes have begun to turn yellow and wilt, one of the following problems is the cause.
1. You are not watering . Both excessive and insufficient moisture are equally dangerous for tomatoes. When the soil is dry, water the tomatoes sparingly. When the optimal mode of irrigation of the beds is restored and the soil is regularly loosened, the plants will quickly come to their senses.
2. Tomatoes get sick . Tomato leaves turn yellow when affected by Fusarium wilt or other diseases. To save the crop, you need to recognize the disease in time and start fighting it. nine0003
3. The plant lacks trace elements and minerals . Perhaps your tomatoes just need to be fed. During the fruit ripening period, plants need complex nitrogen fertilizers.
You can also treat tomatoes with folk remedies .
For example, a solution of comfrey leaves and roots. Infusion of comfrey leaves (1 kg per 10 liters of water, leave for 4-5 days) mixed with a small amount of decoction of comfrey roots. The resulting concentrate is diluted with water in a ratio of 1: 3 and sprayed or watered with tomato bushes. For every 2-3 m of landings, a bucket of solution is consumed. nine0003
4. Root system damaged in tomatoes . The problem can be hidden both in the fact that the roots of plants are eaten by pests, and in the fact that you accidentally damaged the roots when transplanting seedlings into the ground or loosening.
If the problem is mechanical damage, the yellowing of the leaves is due to the fact that the plant devotes all its strength to the formation of new adventitious roots. As soon as the root system recovers, the leaves will return to a healthy green color.
If the roots are damaged by pests, it is necessary to immediately declare "war" on the uninvited guests.
Read about the measures to combat the most common pests of tomatoes in our article. nine0003
5. Humidity too high in greenhouse . The optimal humidity level in a greenhouse or greenhouse for tomatoes is 60-70%. If the air is too humid, the leaves may begin to turn yellow and rot. Especially if the temperature in the greenhouse has dropped below the recommended one.
What Causes Yellow Leaves on Outdoor Tomatoes
Basically, yellow spots on the leaves of outdoor tomatoes appear for the same reasons as when grown under cover. However, there are some nuances. nine0003
1. Low air temperature . This problem is practically unknown to greenhouse tomatoes, but "street" tomatoes during a cold snap can get hypothermia, the result of which is yellowing of the leaves.
2. Infestation by diseases and pests . Fusarium, as well as other diseases of tomatoes, can lead to yellowing of the leaves of the plant. In addition, this problem may indicate that the roots of the plant are affected by pests.
3. Lack of watering . If the street turned out to be hot, dry weather, and the tomatoes did not receive the necessary amount of moisture, their leaves begin to turn yellow.
4. Too much moisture . Excessive watering is also dangerous and threatens with the appearance of yellow spots on the leaves of the tomato.
5. Deficiency of elements and minerals in the soil . Nutrient deficiencies, especially nitrogen and potassium, can also cause yellowing. To return the green color to the leaves of tomatoes, it is necessary to feed them with complex fertilizer. nine0003
6. Root damage . If you break the roots of tomato seedlings when planting or damage them when weeding or loosening, the leaves may turn yellow for a short time. As soon as new roots form on the plant, the green color will return.
Why the leaves of tomato seedlings turn yellow and dry
Yellowing of the leaves of tomato seedlings is most often associated with care errors or improper growing conditions.
Yellowing of seedling leaves - most often the result of hypothermia and improper watering
1. Small container . Cramped conditions do not allow the root system of seedlings to develop normally. And this means that the leaves will certainly turn yellow and fade.
2. Over or under watering . So that the seedlings do not dry out and do not rot, water them moderately.
3. Subcooling . Maintain the optimal temperature for the development of tomato seedlings - 18-22 ° C.
4. Lack of nitrogen . For good growth, seedlings need a sufficient amount of nitrogen in the soil. If you follow all the recommended growing conditions, and the leaves turn yellow anyway, the plants may need a nitrogen supplement. nine0003
5. Lack of lighting . Without good sunlight, photosynthesis is impossible. It is not surprising that tomato seedlings begin to turn yellow in dark rooms.
6. Soil acidity . Any problem is easier to prevent than fix. Therefore, it is advisable to initially use specially prepared soil for growing seedlings. If it turned out that the soil in the containers with seedlings is sour, the situation can be corrected by adding a little ash.
Why do tomato leaves turn yellow after planting
1. Wrong watering . If you water tomato seedlings too hard, or, conversely, irregularly, this can lead to yellow spots on the tomato leaves.
2. Damage to the root system . If the root system of tomatoes does not function well, this will inevitably lead to yellowing of the leaves. The reason may lie in mechanical damage to the roots when planting seedlings, weeding or loosening. In this case, the plant will recover on its own. nine0003
3. Diseases and pests . When the plant is damaged by viruses and diseases, as well as pests, the leaves often begin to turn yellow.
In this case, it is necessary to immediately save the plant and begin the fight against ailments and insects.
4. Hypothermia. If the temperature drops after planting the seedlings in the ground, the seedlings will begin to wither and turn yellow. You can save the situation by prudently covering tomatoes in adverse weather.
What to do if the upper leaves of tomatoes turn yellow
If only the upper leaves of tomatoes turn yellow, while the lower ones remain green, the reason is a lack of nutrients.
Yellowing of upper leaves - a sign of element deficiency
1. Calcium . With calcium deficiency, the upper leaves turn yellow, the tips of the leaves are deformed, the flowers fall off, dark growing spots form on the top of the fruits. If you limed the soil before planting, most likely you overdid it with nitrogen fertilizers, which prevent the free absorption of calcium. You can correct the situation by spraying the bushes with calcium nitrate (20 g per bucket of water).
nine0003
2. Sulfur . Sulfur "starvation" can lead to lignification and thinning of the stems, reddening of the veins and gradual yellowing of the leaves. In this case, the tomatoes are sprayed with a solution of magnesium sulfate (10 g per 10 liters of water).
3. Iron . A symptom of insufficient iron content in the soil is yellow spots in the center of the tomato leaf and along the midrib. To return the plants to a healthy color, they are sprayed with a 1% solution of ferrous sulfate or iron chelate. You can also carry out root dressing with the same substances. The yellowness should go away in a day. nine0003
4. Manganese . Signs of manganese deficiency are similar to those of iron deficiency. The only difference is that the color of the veins is heterogeneous, yellow-green. To restore the required amount of manganese, foliar treatment is carried out with a 1% solution of potassium permanganate.
5.
Boron . Initially, with a lack of boron, the upper leaves retain a green color, but are deformed at the base. If the problem is not solved, the leaves turn yellow, the veins become dark brown. To prevent this, tomatoes are sprayed with a solution of boric acid (10 g per 10 liters of water). nine0003
What to do if lower leaves turn yellow in tomatoes
Yellowing of lower leaves is less dangerous than yellowing of upper leaves, it does not always indicate a disease of the plant. Most often, the plant gets rid of older leaves in order to direct all its resources to the development of fruits.
Yellowing of the lower leaves does not always indicate a serious problem
For tomatoes to feel good, you must follow the recommendation we gave above:
1. Regularly, but moderately water the plants .
2. Avoid hypothermia .
3. Timely carry out complex feeding .
4. Control diseases and pests .
5. Make up the deficiency of elements . For example, yellowing of the first two pairs of true leaves, which is accompanied by their twisting upwards, may indicate a lack of molybdenum. In this case, yellowness first appears in the form of small spots, and then covers the entire surface of the sheet. The leaf veins remain green. In this case, it is necessary to treat the tomatoes with a solution of ammonium molybdate (2 g per 10 liters of water). nine0003
Yellowed lower leaves will sooner or later wither and fall off on their own, but it is better to remove them yourself so that the plants do not waste nutrients on them.
To avoid damaging the skin on the stem of the tomato, carefully remove the leaves. To do this, lower them down, press them against the stem, and only then gently pull them up.
What to do if the edges of tomato leaves turn yellow
Tomato leaves turning yellow at the edges indicate insufficient nutrition of the plant with essential elements.
nine0003
1. Nitrogen . The leaves turn yellow and burn at the edges, later they die. Plants stretch, become weak, stunted. In this case, it is necessary to carry out nitrogen fertilizing. For example, urea (1 tablespoon per 10 liters of water).
2. Potassium . Young leaves are deformed, twisting with a tube, old ones turn yellow at the edges. It is necessary to treat the tomatoes with potassium nitrate (1 tablespoon per 10 liters of water).
What to do if the leaves of tomatoes wither and turn yellow
Withered and yellowed tomato leaves - most often the result of hypothermia or insufficient watering of plants.
1. Warm up the tomatoes . To do this, put them in a warm place and pour water at room temperature.
2. Feed the tomatoes . Wilting and yellowing of the leaves may be due to a deficiency of the necessary elements. You can use complex nitrogen fertilizers.
3.
Remove seedlings from full sun . Direct sunlight is also better to oppress tomatoes. Ideal lighting is diffused light. nine0003
What to do if tomato leaves turn yellow and curl
Tomato leaf curl is an "aggravating circumstance" that indicates more serious problems than simple hypothermia. There are three reasons for yellowing and curling leaves.
If the leaves of tomatoes not only turn yellow, but also curl, the plant needs an ambulance!
1. Lack of minerals and elements . With a shortage of substances necessary for the growth of tomatoes, it is necessary to feed the plants. How to process tomatoes? The easiest way is to apply a ready-made complex fertilizer. In addition, you can sprinkle the bushes with wood ash with a layer of 0.3 cm, or pour 0.5 liters of potassium nitrate solution under each bush (2 tablespoons per bucket of water). nine0003
2. Uneven leaf growth . With a sharp jump in growth, tomato leaves can curl.
This is because the leaf is stretched along, and the leaf plate itself does not have time to grow after the midrib. This problem can be solved by placing the tomatoes in a sunny place.
3. Pest infestation . Twisting of the leaves may indicate that the plant was attacked by tick larvae or aphids. To get rid of pests, you can treat tomatoes with folk remedies. For example, every five days, spray them with an infusion of onion peel (1 cup per bucket of water, leave for a day). You can also spray tomatoes with a 1% solution of potassium permanganate. nine0003
Also take a look at our article on the causes of yellowing of eggplant and pepper leaves.
main causes and solutions to the problem - Ukraine - tsn.ua
All gardeners without exception face a problem when tomato leaves turn yellow. This happens for a variety of reasons. Why and what to do - tells TSN.ua.
Natural causes
Tomato leaves often turn yellow due to natural causes.
For example, after the seedlings were transplanted from separate pots into the ground. In this case, yellow color occurs only in the lower part of the plant. This phenomenon is considered quite natural, because a transplant is stressful for tomatoes. This failure is temporary. Therefore, do not panic. Better wait a few days. If during this time the yellowed leaves do not fall off, you will have to remove it manually. nine0003
Yellowing due to diseases and pests
Some diseases can cause yellowing of tomato leaves. For example, they include mosaic, late blight, fusarium, etc. Usually yellow leaves are the first symptom, so fungicides should be applied as soon as possible.
Tomato leaves also turn yellow due to pests, in particular aphids, whiteflies, Colorado potato beetles, tobacco thrips. Insecticides are effective against them.
Deficit or excess of moisture in the soil
When tomatoes face a shortage of water, they begin to save it, try at all costs to reduce the evaporation of moisture, and therefore begin to get rid of the leaves, which first turn yellow and then fall off.
If there is little water in the soil, the leaves will curl.
If there is too much moisture, this also negatively affects the condition of the tomatoes. In this case, the plant begins to form too large a vegetative mass, new leaves are formed that absorb nutrients. Therefore, in the upper layer of the soil there is a deficiency of minerals, especially nitrogen. Over time, the leaves of tomatoes turn yellow. If it so happened that you poured your tomatoes, you need to stop watering and add nitrogen to the ground. nine0003
Too much or too little sun
When a plant is planted in an open area in a sparse planting pattern, it may suffer from strong sunlight while the seedlings are not yet fully established. Therefore, in case of extreme heat, be sure to shade the tomatoes during the first weeks.
But if the planting pattern is thickened, tomato leaves usually turn yellow at the bottom or inside the bush. Such plants are dangerous to transplant, it is better to simply thin out the leaves, removing the shadows that shade others.
nine0003
Problems with the root system
Quite a common problem with tomatoes. After all, tomato leaves turn yellow on those bushes that have a poorly developed root system. It cannot provide sufficient nutrition to the ground mass and starvation occurs. In this case, you can help the plant by using growth stimulants. Foliar top dressing also helps restore balance.
Deficiency or excess of nutrients
This is the main reason why tomato leaves turn yellow. But before you act, you need to understand which particular battery is too much or not enough. nine0003
Excess or deficiency of nitrogen
Does the plant look weak, young leaves are small, and old shoots become discolored and yellow? This is a nitrogen deficiency. If you notice such problems, you need to add urea or mullein. Effectively acts bird droppings in combination with ash.
However, do not exceed the amount of fertilizer, because an excess of nitrogen leads to the accumulation of a large amount of vegetative mass, which can also cause yellowing of the leaves.
Phosphorus
Another important nutrient for tomatoes. With its deficiency, the leaves curl and decrease, subsequently they turn yellow. Often the stems turn purple or dark green. If you notice such a problem, you need to feed the plant with superphosphate. Sometimes gardeners also bury fish heads next to the beds. However, it is very important not to oversaturate the tomatoes with phosphorus.
Potassium
When the plant is deficient in potassium, the leaves at the bottom of the stem turn yellow and then dry out. First, the plant is recommended to be treated with potassium, soluble in water. And after 2-3 treatments, add potassium sulfate to the soil. nine0003
Magnesium
If tomato leaves are turning yellow, it could be a magnesium deficiency. In this case, the color changes in places between the veins. Also, the leaves are often curled towards the middle, and the old ones may be covered with gray-brown spots. To get rid of the problem, foliar fertilizing with magnesium nitrate is used.
