Why do phlox leaves dry (turn yellow): photos, causes, treatment

Content

1 List of reasons why phloxes turn yellow and dry out
2 What to do if phlox leaves turn yellow and the cause has not been established
3 Prevention measures
4 Conclusion

Phlox leaves dry out - this symptom cannot be ignored. First of all, it is recommended to increase watering and feed the flowers with nitrogen fertilizers. If this does not have an effect, most likely the bushes are affected by the disease. Then you should treat with a fungicide. In some cases, bushes have to be dug up and burned because the diseases are incurable.

List of reasons why phloxes turn yellow and dry out

The reasons for yellowing leaves of phlox can be very different, but most often they are associated with improper care - lack of moisture and insufficient fertilizer. If normal care is provided, the leaves dry out due to diseases (for example, root rot, mosaic) or exposure to pests (spider mites, stem nematodes and others).

Violation of landing rules

Very often phloxes dry out already in the first season. The most likely reason is due to non-compliance with planting rules:

Phlox leaves dry out due to the hot sun, so they need to be planted in partial shade from shrubs or trees.Otherwise, the foliage gets burned, especially after watering, when drops of water fall on it.
Stagnation of moisture has a negative effect. Phloxes dry out and gradually die. This is often observed if seedlings are planted in a lowland. Therefore, it is advisable to make a slight slope so that precipitation flows down.

Phlox prefer partial shade, so it is better to plant them close to shrubs, trees or buildings

Violation of the rules of care

Phlox leaves turn yellow and dry due to improper care:

Lack of moisture: flowers need to be watered early in the morning or evening at the rate of 2 buckets per 1 m². In this case, water is given directly at the root - it is important to ensure that it does not fall on the leaves. The frequency of watering depends on precipitation: during drought - 2 times a week, during rainy periods - once every 7-10 days.
Lack of loosening can also lead to leaf wilting. The soil needs to be loosened 1-2 times a month, especially after applying fertilizers. Then the nutrients will quickly flow to the roots, and from there they will spread throughout the plant.
Another reason is infertile soil and lack of fertilizing. If the leaves dry out and the phlox grows slowly, it means they are experiencing a nitrogen deficiency. Such fertilizing is usually applied in April or May. You can use urea, ammonium nitrate or complex fertilizer. An alternative option is organic matter (slurry, mullein or bird droppings). In all cases, follow the instructions. It is worth keeping in mind that fresh manure should not be used - it will most likely lead to root rot.
Often the lower leaves of phlox dry out due to lack of care: when weeds constantly appear around the plant, they inhibit its growth and take away moisture and nutrients.You can fight them by weeding and mulching the roots.

Advice! If phlox leaves dry out from lack of moisture, and it is not possible to frequently water the soil, a layer of mulch will help keep it moist for as long as possible.

Hay, sawdust, pine needles and other available materials are suitable for covering the tree trunk circle.

Weather

Most varieties of phlox are undemanding to care and weather conditions. They tolerate heat quite well, especially if, after abundant watering, a layer of mulch is placed on the ground.

However, during prolonged drought, the leaves begin to dry out and turn yellow. First they wither, then the plant bends to the ground. If nothing is done, the bush will die. To prevent this, it is necessary to ensure timely watering. Moreover, in hot weather it can be increased to 2 times a week (1.5-2 buckets per 1 m² flower beds).

Very often, phlox leaves dry out due to lack of moisture.

Attention! If you water the bushes with too cold water (from a well or tap) in hot weather, this can lead to cracking of the stems. As a result, the pathogen can easily penetrate into the exposed tissue, which can lead to drying of the leaves and death of the plant.

Pests

Pests pose a particular danger because they not only cause the leaves to turn yellow and dry out, but the entire plant can die. In some cases, insects cannot be controlled. Then the bush should be dug up and burned so that neighboring plants do not have time to suffer.

Nematode

Sometimes the appearance of a stem nematode leads to drying of the leaves and general wilting of the plant. This is a very dangerous pest that affects the entire flower. External signs are:

leaves dry and curl;
the tips of the shoots become weak and thin;
growth slows down, the plant fades;
the inflorescences are formed ugly, the flowers are small.

Unfortunately, it is not possible to completely destroy the nematode. Therefore, the bush is simply dug up, taken away and burned. The place where it grew must be disinfected. To do this, you can use a 1-2% solution of potassium permanganate or any copper-containing product. The resulting preparation is watered generously over every square meter of soil. Then, the very next season, the soil is dug up and nasturtiums or marigolds are planted.

Important! If phloxes have been affected by a nematode, they should not be planted in the same place for 4-5 years.

Spider mite

Spider mites are a very common pest that causes leaves to dry out not only on phlox, but also on many other plants. Signs of infestation by these insects are easy to identify:

Small light dots appear in large numbers on the inside of the leaves;
gradually the leaf plate begins to turn white and dry out;
the naked eye can see colonies of mites on the shoots, as well as a thin cobweb on the foliage and stems;
phlox noticeably lags behind in development, for example, inflorescences do not form, growth slows down greatly.

To cope with this unpleasant pest, it is recommended to tear off all yellowed leaves and take them outside the flower garden. There it is better to burn them or place them in sealed bags and throw them away. The plant itself must be treated with an insecticide, for example:

"Aktellik";
"Fitoverm";
"Neoron";
"Skelta" and others.

It is enough to choose one of these means. You must act according to the instructions.

A clear sign of a mite is a thin silvery web on the leaves and shoots

Important! Treatment is carried out in calm, dry weather.It is advisable to do this late in the evening, otherwise the sun's rays may burn the phlox leaves, causing yellow spots to remain on them.

Diseases

If the care is good enough, watering is moderate, fertilizing is applied regularly, but the leaves still turn yellow and dry, the reason may be associated with infectious diseases. Depending on the type of pathogen, they are divided into viral, fungal and mycoplasma.

Viral

If phlox leaves turn yellow (and not only the lower ones, but also the rest), this may be associated with viral diseases. The most common cause is common mosaic, which is caused by the pathogen Pisum virus 2 Smith.

The first symptoms can be detected even in young phloxes. Their leaves become slightly lighter along the veins. Then pale yellow rings and spots appear. Over time, they turn green, causing the entire surface to become one large “spot.” As a result, the leaves dry out and the phloxes die. The problem is that no effective treatment for mosaic has yet been discovered. Therefore, the plant is simply dug up and taken away or burned.

Important! It is necessary to remove phlox affected by mosaic as early as possible so that it does not have time to infect neighboring plants.

External symptoms of tobacco mosaic: leaves become covered with yellow spots, dry out and die

Fungal

If the lower leaves of phlox turn yellow, the cause may also be due to a fungal infection. One of the most common diseases is root rot. The fungus settles on root fibers, most often in the neck area. The roots begin to rot and then die, which can cause the entire plant to die.

External signs of phlox being damaged by root rot:

first the lower leaves dry and turn yellow, then the upper ones;
the foliage becomes covered with brown spots;
the plant becomes very lethargic and literally lies on the ground;
even if the plant does not wither, its growth rate slows down, despite watering and fertilizing.

Important! Root rot actively develops in case of excessive watering of phlox. Therefore, it is necessary to ensure that the top layer of soil remains slightly moist. An excess of water is often even more harmful than a lack.

Phoma is another common fungal disease that causes the leaves of phlox and other crops to dry out. Fungi begin to spread during the formation of buds. External signs of pathology:

The lower leaves curl and dry out.
The skin on the lower part of the stem (up to 15 cm in height) becomes brown in color, and the tissues become loose.
The shoot also becomes abundantly covered with cracks, after which the stem weakens and breaks even from a slight touch.

It is quite difficult to fight fomoz, so it is better to organize prevention in advance, for example, spray the green part with a 1% solution of Bordeaux mixture. It is better to dig up the affected bush and burn it.

Sometimes plants are also affected by a fungal pathogen such as septoria. The second name for this disease is leaf spot. Its main stages:

First, small spots of light gray color appear on the leaf. They are often round, but come in other shapes.
Then the spots enlarge and turn yellow, with a burgundy border appearing around them.
The infection quickly spreads throughout the phlox, its leaves dry out and the stem begins to die.
If half the bush is affected, its death is inevitable.

Rust also shows similar signs - in this case, brown spots appear on the leaves, which is why they begin to dry out and die. Most often, rust affects dark phloxes, so they are monitored with special care.

Powdery mildew is a fungal disease of phlox. It usually appears in early August. Stages of defeat:

Pale spots appear on the lower leaves of phlox.
At first they are small, then they increase in size and begin to merge.
The infection spreads to the upper leaves.
If the disease is advanced, the leaves begin to dry out and the plant begins to wither.

At this stage, nothing can be done to help the phlox. The flower has to be dug up, taken away and burned.

Powdery mildew can be recognized by the appearance of a white coating on the leaves

Mycoplasma

Mycoplasma diseases are a type of fungal infection. One of them is jaundice. External signs of damage:

phloxes are very behind in development;
the leaves begin to curl and become pale;
many small side shoots appear on the stems;
if the flowers have already formed, their petals and stamens “merge”, turning into a kind of “leaves”.

It is not so easy to defeat jaundice; the affected bush will have to be dug up and destroyed. As a preventive measure, phlox should be treated with any fungicide.

What to do if phlox leaves turn yellow and the cause has not been established

In such cases, it is advisable to make sure that the plant is not affected by a dangerous infectious disease (otherwise it must be removed, otherwise neighboring phloxes will become infected). Then you can experiment with watering and fertilizers.

Surely, if the bushes lack moisture or nutrients, these measures will be sufficient.The first signs of improvement will be noticeable within a week. But if even after this there is no effect, it may well be that the phloxes are suffering due to heavy clay soil. Then the flowers can be transplanted to a new place. The hole must first be filled with fertile soil from a mixture of well-loosened garden soil and humus. It is better to do this at the end of summer or early autumn.

Important! If the soil and care are good, but the phloxes turn yellow, this may be associated with the development of a dangerous disease. This is especially likely if nearby plants remain healthy. Then the affected bush must be quickly dug up and burned.

Prevention measures

Yellowing of leaves and other deviations are easier to prevent than to deal with them. In many cases, treatment of phlox is impossible. Therefore, it is advisable to immediately provide the flowers with normal care - regular (but moderate) watering, fertilizing, and also take preventative measures against diseases - in April or May, treat with any means (one to choose from):

Bordeaux mixture;
"Ordan";
"Maksim";
"Fitosporin";
"Skor" and others.

Secondary treatment can be carried out after a month. If in the previous season the plants already suffered from fungi and other pathogens, a third treatment will be necessary (also with an interval of 1 month).

Important! In spring, you should mulch the roots and feed the phlox with nitrogen. You must act exactly according to the instructions, because excessive amounts of fertilizing have a negative impact on the condition of the crop.

Conclusion

Phlox leaves dry out most often due to disease, but the reasons can be very different. Beginning gardeners do not always correctly calculate the amount of watering and fertilizer, so seedlings may dry out and disappear.It is important to carry out timely prevention. Treating bushes is very difficult and not always effective.