The beautiful flowering phlox herb is one of the most beloved flower crops among flower growers. Bright flowers delight the eye throughout the season, while not requiring special care. However, sometimes their flowering can be prevented by diseases that accelerate the wilting process. Moreover, severe lesions can spread from a diseased flower to healthy neighbors, which ultimately harms the entire flowerbed. The most common symptom of the disease is yellowing of the lower leaves of the plant. Below in the article, it is examined in detail why the leaves of phlox turn yellow and how to deal with it.
What diseases can be the cause
Phloxes may be affected:
- viral diseases;
- fungal diseases;
- mycoplasmal diseases;
- pests.
Beautiful flowering phlox herb
In addition, due to improper care of the flower, physiological damage can occur.
Important! If an unhealthy, but suspicious plant is identified, it must be planted off from the others or covered with linen bags with inflorescences. Insulation of the flower will prevent the spread of the disease throughout the flower bed.
In phlox, the lower leaves turn yellow: what to do
Viral diseases
Viral infections are spread by garden pests: aphids, ticks, cicadas, and roundworms. Diseases of this kind are quite rare and do not cause much damage to flower crops. However, understanding the causes of phlox disease and knowing the methods for their treatment can save plants and prevent mass infection.
The yellowness of the leaves may indicate damage to the plant by the curly virus. In this case, a noticeable modification of the leaves occurs. Their surface is covered with numerous yellowish or black spots, the veins become brown, the greens begin to dry, and the leaves themselves are twisted into a spiral. The bush, having weak short shoots, acquires signs of dwarfism. Phloxes lose their ability to bloom on their own and may even die.
Note! To save the plant, you need to use the complex chemical preparation fungicide scor (or its analogue). After removing traces of infection (yellow and black spotted leaves) from the bushes, you need to spray them with the drug.
In addition, all trash under the plant should be removed. If no means helped to get rid of the infection, then the plant needs to be dug up and destroyed.
In addition, phlox can be affected by ring spotting. The disease makes itself felt from the end of spring to the beginning of summer. The first sign is the manifestation of light or yellowish spots on the leaves. The virus spreads over time throughout the green mass. Phlox leaves twist, the plant is deformed, the bush looks painful. The cause of infection is in the activity of the soil nematode. In most cases, the plant is not subject to treatment.
The next step after finding out the reason why phlox leaves turn yellow is to understand what needs to be done to cure the plant. With a constant, thorough inspection of plantings, timely detection and destruction of infected flowers, serious consequences of the activity of most viruses can be avoided. The main carriers of plant-hazardous viruses are nematodes. First of all, it is necessary to check the soil for infection with precisely these multicellular individuals. When they are detected, the site is treated with nematicides.
In addition, an infected garden tool (secateurs) can become the cause of the spread of infection. The virus can also be carried by moles, fallen flowers from diseased plants and other plant debris. Florists noticed that diseases can be transmitted by using cuttings and seeds from diseased plants.
Note! In order to quickly cope with the problem in case of infection, it is recommended to equip a small area (quarantine) for incoming crops. In addition, the pits in which the diseased flowers were located should be etched.
Fungal diseases
Fungal diseases usually fall on the plant along with rainfall. This happens if the flower grows in the fresh air and does not have a hinged shelter. Cool rainy periods and temperature fluctuations are a good time for the development of fungal spores.
If the lower leaves of phloxes were covered with yellowish-brown spots, and the foliage of the upper tier acquired a yellow color, then this is most likely a phomosis. This disease is caused by the activity of Thomas fungus, which affects the base of flower shoots and stains them in brown color. 6-7 days after infection, the leaves begin to curl and dry. From below, the sheet plate is covered with dark dots and blackens. The elasticity of the barrel is significantly reduced, cracking may even occur. The flower leans against the ground or breaks. The virus usually attacks perennial (2-3 year old) plants.
Fungal diseases
Now you need to figure out what to do if the phlox has yellowed leaves due to a fungal disease.
Treatment of phomosis is a very difficult task, therefore, the procedure should be started only if the infected plant belongs to a rare variety. The procedure is as follows:
- Cut off tops from uninfected shoots.
- Place the cuttings in a fungicide solution (foundationazole, maxim).
- Land them in a remote and isolated area.
Note! To control the spread of infection, it is necessary to spray the phloxes with a copper-containing preparation once every 10 days (Abiga peak, home and Bordeaux liquid 1% solution are suitable).
Mycoplasmal diseases
The causative agents of mycoplasma diseases are pathogenic organisms. Disease carriers are some types of cicadas. When mycoplasma enters their body, the incubation period begins, therefore, the spread of infection proceeds more slowly than with other types of diseases. The spread of the disease can also be triggered by the reproduction of phlox (during vegetation).
The most effective way to fight is the destruction of infected flowers. However, those who are very sorry to destroy the plant may try to cure it. This should be done using aqueous solutions of antibiotics.
Pests
In addition, pests that regale on the tissues and juice of these flowers can affect the yellowing of phloxes. Here is some of them:
- caterpillars
- slobbery pennies;
- slugs.
Pests
How to deal with them
The most environmentally friendly way is to catch pests. They can be collected manually or set traps. For example, beer or yeast attracts slugs well. In addition, lime, ash and superphosphates are suitable for fighting. These drugs can help if they are scattered around the bushes.
Note! Also, the cruciferous flea can harm the plant, which can be combated with the help of anti-flea dog shampoo, as well as the previously mentioned nematodes, which leave the flower almost no chance of cure.
Tick spider
Another dangerous pest is a tick spider. A small arachnid insect feeds mainly on foliage. If faint light stripes are observed on the leaves, then these are traces of the activity of the tick spider.
Insecticidal oils and soap will help get rid of these insects. Moreover, they will be effective only when applying funds to the parasites themselves. As a prophylaxis, you can spray a weak solution of soap and oil on plants up to 1 time in two weeks. Some gardeners recommend controlling pests with a carbaryl spray.
Tick spider
Heavy humidity
Another reason for the yellowing of the lower leaves of the phlox is its excessive moisture. In most cases, phlox needs a moderately moist soil for normal development. With too much fluid, the plant ceases to receive enough nutrients, which leads to waterlogging of the roots and a weak supply of oxygen. As a result, the rhizome begins to rot, and the first sign of this is yellow leaves.
Note! No need to water phlox if the topsoil (2-3 cm) is saturated with moisture. When stagnating water, it is necessary to think about improving drainage, and compost and medium pebbles (in small quantities) should be added to the topsoil.
What to do to help the plant
Proper care of the flower will significantly reduce the risks of its disease. For this, it is necessary to regularly carry out comprehensive protective measures. Compliance with agricultural technology (periodic watering, removal of weeds and pests, sanitary treatment and top dressing) will also largely protect the plant from potential threats. In addition, it should be borne in mind that the growth of phlox in the same soil for a long time provokes the multiplication of microorganisms that adversely affect the flower. Do not forget about the hygiene of the place of growth. If the plant is already sick, it is necessary to determine the cause of infection and, depending on this, choose one of the treatment methods described in the previous sections.
Help the plant
Why do phloxes turn yellow leaves? The main reason is improper care of the plant. This may be improper soil, insufficient / excessive moisture or untimely inspection of the flower. Prevention is another important factor, ignoring which can lead to the development and spread of the disease. However, if the disease has already affected the plant, and signs of yellowing have begun to appear on it, then urgent measures must be taken. Even if the diseased phlox cannot be saved, then operational actions will save other representatives of this culture from the harmful effects.
