Why tomato seedlings turn yellow: what to do

Content

1 What tomatoes need to grow successfully
2 Causes of yellowing leaves of tomato seedlings
3 What to do if the leaves of tomato seedlings turn yellow

Tomato is always a welcome vegetable on our table. And although it appeared in the European diet not so long ago, it is difficult to imagine summer without a salad of fresh tomatoes or a winter table without canned tomatoes. What about borscht and cabbage soup without tomato juice or tomato paste? And the various sauces that we are so accustomed to? No, the sudden disappearance of this otherwise wonderful vegetable from our diet would be a disaster. In addition, tomatoes can be grown in almost any climate zone, if not in open ground, then in the greenhouse or greenhouse. We often grow tomato seedlings ourselves. And although caring for her cannot be called too difficult or burdensome, problems do not arise as rarely as we would like. In this article we will find out why tomato seedlings turn yellow.

What tomatoes need to grow successfully

To get a good harvest, you need healthy seedlings, and for this it is advisable to clearly understand what the plant likes and what should not be allowed when growing it. Let's first figure out what tomatoes like:

Soil with a neutral reaction or slightly acidic;
Phosphorus fertilizers;
Bright sun;
Influx of fresh air;
Economical, uniform soil moisture;
Warm, dry air.

They don't like tomatoes:

Excess fertilizers, especially nitrogen;
Feeding with fresh manure;
Air stagnation;
Thickened plantings;
Waterlogging of the soil;
Watering with cold water;
Irregular watering;
High humidity;
Prolonged cold snap;
Heat above 36 degrees;
Acidic, heavy soils.

Causes of yellowing leaves of tomato seedlings

Tomato seedlings turn yellow for various reasons, often unrelated to each other. Most often this is:

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

Yellowing of 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, we 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. The seeds need to germinate, and this is not so easy to do through dense soil. In addition, tomato sprouts are tender and their roots are weak.It is also impossible to take purchased soil left over after planting indoor flowers - it is intended for adult plants and 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 soil for seedlings.

Tomato seedlings turn yellow if the soil:

sour;
contains a lot of fertilizers;
too dense;
becomes crusty 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 depression and death of the entire plant;
alkaline - this can cause chlorosis.

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

As we wrote above, tomatoes like moderate and even watering. If you regularly flood them, the soil will turn sour 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 sparingly - and this will cause the leaves of the tomato seedlings to turn yellow. Watering should not be excessive, but sufficient. Firstly, if there is a lack of moisture, the leaves can simply dry up, and, secondly, the absorption of nutrients in dry soil is significantly worse. Nitrogen and phosphorus from the leaves move to the stem, which causes them to turn yellow.

If you water tomatoes with hard water, salting may form on the soil - they can be identified if the surface of the soil becomes covered with a whitish crust or white or yellowish spots appear on it. Roots pull nutrients from the plant and release them to the soil.

Mistakes in feeding seedlings that can lead to yellowing of leaves

Leaves may turn yellow due to a lack or excess of nitrogen. Tomato nutrition must be balanced; the plant needs nitrogen 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 turn yellow first.

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

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

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

Consequences of insufficient lighting of tomato seedlings

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

Residents of northern regions, where daylight hours in spring are very short, face this problem especially often. The solution is to illuminate the tomatoes with a fluorescent lamp. Even better - buy a phytolamp, now its price is not very high, and it will last for many years.

Attention! Problems caused by a lack of lighting do not end with yellowing leaves - do not allow this to happen.

It should be noted that tomatoes cannot be illuminated around the clock - we risk that the leaves will turn yellow from chlorosis - a lack of iron, which simply stops being absorbed.

Consequences of close planting of tomato seedlings

Don't sow the seeds too thickly! The authors of all articles on growing tomato seedlings never tire of writing about this, but we make this mistake again and again. The seedlings are stretched due to lack of light, they are cramped, which in itself can cause yellowing of the leaves. In addition, the nutritional area is significantly reduced and the root does not develop normally.

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

Other reasons causing 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 cause of yellowing leaves may be:

Poor quality fertilizer or fertilizer that we simply dissolved poorly in water. As a result, grains containing nitrogen fell on the leaves and burned them;
Watering at noon on a sunny day can cause sunburn on the leaves. It can be mistaken for yellowing of leaves;
Our beloved cat confused a 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. It rarely occurs in seedlings; most often it affects adult tomatoes.

What to do if the leaves of tomato seedlings turn yellow

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

If we haven't overwatered the tomatoes too much, the leaves have turned yellow, but the soil hasn't turned sour, dusting the soil with ash and reducing watering can help.

Urgent transplantation into new soil will be required if:

The overflow is strong, the soil has turned sour;
We initially sowed seeds or planted seedlings in acidic or excessively alkaline soil;
The seedlings were overfed or watered with hard water, which caused salting of the soil;
Plants are spaced very closely or in pots that are not large enough.

For this:

Prepare a container with soil suitable for growing seedlings, moisten it slightly;
Remove young tomatoes from the old soil, clean the roots and destroy all plants with a black leg or rotten root;
Plant the seedlings in new soil;
Using a teaspoon or tablespoon, depending on the size of the transplanted tomato, pour each sprout separately with the solution foundationazole or a slightly pink solution of potassium permanganate;
Shade the planting for several days and limit watering;
When the seedlings recover from transplanting, provide them with 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’s even better to simultaneously feed the seedlings foliar with chelates - they are usually sold packaged in bags designed to be dissolved in two liters of water.

Whatever the reason for the yellowing of tomato leaves, treat them leaf by leaf with 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?