Why tomato seedlings turn yellow: what to do

Content

1 What tomatoes need for successful growth
2 Causes of yellowing of tomato seedling leaves
3 What to do if tomato seedling leaves turn yellow

The tomato is always a welcome vegetable on our table. And although it appeared in the diet of Europeans not so long ago, it is difficult to imagine a summer without a salad of fresh tomatoes or a winter table without canned tomatoes. And borscht and cabbage soup without tomato juice or tomato paste? And the variety of sauces that we are so used to? No, the sudden disappearance of this in every way wonderful vegetable from our diet would be a disaster. In addition, tomatoes can be grown in almost any climatic zone, if not outdoors, then in the greenhouse or a greenhouse. We often grow tomato seedlings on our own. While caring for her is not too difficult or cumbersome, problems are not as rare as we would like. In this article we will find out why tomato seedlings turn yellow.

What tomatoes need for successful growth

To get a good harvest, you need a healthy seedling, and for this it is advisable to clearly understand what the plant loves and what should not be allowed during its cultivation. Let's first figure out what tomatoes love:

The soil is neutral or slightly acidic;
Phosphate fertilizers;
Bright sun;
Fresh air inflow;
Economical, uniform soil moistening;
Warm, dry air.

They don't like tomatoes:

Excess fertilizer, especially nitrogen;
Top dressing with fresh manure;
Stagnant air;
Thickened planting;
Waterlogging of the soil;
Watering with cold water;
Irregular watering;
High humidity;
Prolonged cold snap;
Heat above 36 degrees;
Sour, heavy soils.

Causes of yellowing of tomato seedling leaves

Tomato seedlings turn yellow for various reasons, often not related to each other. Most often these are:

The quality of the soil for growing seedlings;
Improper watering;
Lack or excess of nutrients;
Insufficient lighting;
Close fit;
Other reasons.

Yellowing of the leaves does not always lead to the death of tomato seedlings or even to some serious consequences, but only if measures were taken immediately. In any case, you need to know exactly what mistakes we made, so as not to repeat them in the future. Let's take a closer look at each of the possible reasons why the leaves of tomato seedlings turn yellow.

Soil for growing tomato seedlings

To grow high-quality seedlings, you cannot simply take garden soil or soil from a greenhouse. Seeds need to germinate, and it is not so easy to do this through dense soil. In addition, tomato sprouts are tender and their roots are weak. It is also impossible to take purchased soil left after planting indoor flowers - it is intended for adult plants, it may be too heavy or acidic for seedlings. In addition, fertilizers have already been added to it in a concentration suitable for growing an adult plant.

Advice! Plant seeds only in special seedling soil.

Tomato seedlings turn yellow if the soil:

sour;
contains a lot of fertilizers;
too dense;
is covered with a crust due to its mechanical properties or watering with hard water, which impairs the supply of oxygen to the roots and can cause not only yellowing of the leaves, but oppression and death of the entire plant;
alkaline - this can cause chlorosis.

Errors in watering, as the cause of yellowing of the leaves of tomato seedlings

As we wrote above, tomatoes like watering moderate and even. If you pour them regularly, the soil will acidify and air will not flow to the roots, the sprouts will begin to slowly die, and this will begin with yellowing of the lower and cotyledon leaves.

It is also impossible to water poorly - and from this the leaves of tomato seedlings turn yellow. Watering should not be excessive, but sufficient. Firstly, with a lack of moisture, the leaves can simply dry up, and, secondly, the assimilation of nutrients in dry soil is significantly impaired. Nitrogen and phosphorus from the leaves moves to the stem, which causes them to turn yellow.

If tomatoes are watered with hard water, salinity can form on the soil - they can be determined if the surface of the soil is covered with a whitish crust or white or yellowish spots appear on it. The roots pull nutrients from the plant and release them to the soil.

Mistakes in seedling feeding that can lead to yellowing of the leaves

Leaves may turn yellow due to a lack or excess of nitrogen. Tomato nutrition should be balanced, nitrogen is needed by the plant at all stages of development - it is part of proteins and chlorophyll. Interestingly, nitrogen is very mobile, the plant independently transfers it to where it is needed most: for example, from old leaves to young ones. Thus, during nitrogen starvation, the lower leaves first turn yellow.

Comment! Excess fertilizer can cause salting in the same way as watering with hard water.

The tips of the leaves of a tomato can turn yellow or dry out due to a lack of potassium, which, in addition to a lack of this element in the soil, can be caused by acidic soil. In this case, potassium is not used for food, but for deoxidizing the soil.

Important! At low temperatures, nutrients will simply not be absorbed, which will cause yellowing of the leaves, and, in general, slow down development.

Consequences of insufficient lighting of tomato seedlings

The tomato is a plant of long daylight hours. He needs good lighting for at least 12 hours a day for normal life. We all know this, we all understand, but for some reason we often put it in an insufficiently lit place, and then ask why the leaves of tomato seedlings turn yellow.

Especially often, residents of the northern regions face this problem, where daylight hours in spring are very short. Exit - light the tomatoes with a fluorescent lamp. Even better - buy a phytolamp, now its price is not very high, but it will last for many years.

Attention! Problems caused by lack of lighting and yellowing of leaves do not end there - do not allow this.

It should be noted that it is impossible to light up tomatoes around the clock - we run the risk that the leaves will turn yellow from chlorosis - a lack of iron, which will simply cease to be absorbed.

Consequences of close planting of tomato seedlings

Don't sow seeds too thick! The authors of all articles on growing tomato seedlings do not get tired of writing about this, but we make this mistake again and again. Seedlings are pulled out due to lack of light, they are cramped, which in itself can cause yellowing of the leaves. In addition, the feeding area is significantly reduced and the root does not develop normally.

Warning! Thickened planting of tomatoes provokes the appearance of late blight.

Other causes of yellowing of tomato seedlings

An article describing the causes of yellowing of tomato leaves will not be complete if we do not dwell on points that are rare. So, the reason for the yellowing of the leaves can be:

Poor quality fertilizer or fertilizer that we just poorly dissolved in water. As a result, grains containing nitrogen fell on the leaves and burned them;
Watering at noon on a sunny day - leaves can get sunburn. It can be mistaken for yellowing of the leaves;
Our beloved kitty or cat confused the box with seedlings with a toilet.By the way, this happens quite often if the animal gets free access to the room where we grow seedlings;
Fusarium leaf wilt. In seedlings, it is rare, most often adult tomatoes are ill with it.

What to do if tomato seedling leaves turn yellow

Tomato seedlings turn yellow, what should I do? We have already figured out the reasons, now let's save the seedlings.

If we did not overflow the tomatoes very much, the leaves turned yellow, but the soil did not sour, dusting the soil with ash and reducing watering can help.

An urgent transplant into new soil will be required if:

Overflowing strong, the soil turned sour;
We initially sowed seeds or cut seedlings into acidic or overly alkaline soil;
The seedlings were overfed or watered with hard water, which caused salinity of the soil;
Plants are very crowded or in insufficiently large pots.

For this:

Prepare a container with soil suitable for growing seedlings, slightly moisten it;
Remove young tomatoes from old soil, peel the roots and destroy all plants with black legs or rotten roots;
Plant the seedlings in new soil;
With a teaspoon or tablespoon, depending on the size of the transplanted tomato, pour each sprout separately with a solution foundazola or a slightly pink solution of potassium permanganate;
Shade the planting for a few days and limit watering;
When the seedlings recover from transplanting, provide maximum light for 12-15 hours a day.

If the yellowing of tomato leaves is caused by a lack of fertilizer, feed the plants. It is even better to give the seedlings a foliar feeding with chelates at the same time - they are usually sold packaged in bags designed to dissolve in two liters of water.

Whatever the reason for the yellowing of tomato leaves, treat them on the leaf with an epin solution - it will smooth out the effects of any negative factors.

We offer you to watch a video that can be useful both when growing seedlings and when caring for tomatoes in the ground:

As you can see, in order for tomatoes to develop normally, you just need to follow all the rules for sowing seeds and caring for seedlings.

Why do the leaves of tomato seedlings turn yellow