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Boxwood, or buxus, as it is also called, is a very beautiful ornamental plant. In care, it is quite unpretentious. But at the same time, it is often exposed to various diseases and pests that can lead to the death of the bush. If the appearance of the boxwood has changed, and its foliage has begun to dry, turned yellow, covered with spots or holes, then it is necessary to find out the cause of this condition as soon as possible. To correctly identify boxwood diseases, a photo and a detailed description of the signs of infection will help gardeners take timely measures to save it.
Boxwood diseases and their treatment
Like many other ornamental plants, boxwood often suffers from various diseases. Most of them are fungal in nature and are caused by spores of fungi of a certain type. There are several main most common diseases. Below are the signs of various boxwood diseases, methods for their treatment and photos.
White leaf spot of boxwood
The disease has another name – septoria. The causative agent is many varieties of fungi of the genus Septoria. Light spots with bright black edging grow on leaves and shoots. The process continues with the reproduction of spores of the fungus, as a result of which the leaves turn brown. Boxwood becomes severely weakened and vulnerable to other diseases and pests. Affected leaves fall prematurely, young shoots die, bushes stop blooming.
The fight against the disease is carried out in 3 stages:
- Affected leaves and shoots are removed in such a way that the healthy part of the boxwood is captured when cutting.
- The resulting sections are disinfected.
- The plant is sprayed with fungicides – Profit, Ridomit Gold or Bordeaux liquid.
Cool, damp weather promotes the spread of fungus with wind, rain, and insects. Spores of a fungal pathogen can persist for a long time in seeds, on shoots and garden tools. To stop the activation of the fungus, it is necessary to destroy plant residues and disinfect all tools.
Death of foliage and shoots
The disease manifests itself in spring, during the growth of shoots and young foliage. This happens as a result of damage to the plant by the fungal pathogen Volutella buxi. The leafy tops of the shoots begin to change color. At first they turn red, after a while – bronze, at the end of the process – yellow. Branches affected by the disease die off. If diseased shoots are cut open, exfoliated bark and dark circles will become visible, alternating with colorless wood. Leaves and stems turn pink in wet weather.
The fungus is almost impossible to remove. It is resistant to various chemicals designed to combat such pathogens. Boxwood can only be saved if the damaged stems are removed. To do this, they are cut off, and the fallen leaves are collected and taken out of the site. In case of severe damage to the entire boxwood bush, you can resort to the help of fungicidal agents, the composition of which contains copper.
leaf shedding
This is a more serious and dangerous leaf shedding fungus that invades new surfaces at an astonishing rate. Foliage, and behind it the young shoots die off and fall off. At the same time, oblong spots of a dark shade first appear on the shoots.
The disease is activated mainly in the summer, in bad weather. As a result of the disease, boxwood may completely or partially die. In order to combat the pathogen, it is necessary to destroy all infected leaves and branches, including already fallen ones. To carry out preventive protection measures, the bushes are treated with fungicides before the onset of bad weather. The photo shows the successive stages of the boxwood disease.
Rust
Airborne by spores of the fungus Gymnosporangium sabinae. When infected, brown pads appear on the upper and lower surface of the leaves. Affected foliage should be collected. The plant must be treated with Agipa-Peak, Topah or Bordeaux mixture.
The spores of the fungus infect the leaves of pears and are able to fly very far. Therefore, both plants should not be planted next to each other. Affected boxwood shoots must be carefully cut and removed.
Stem base rot
White rot is the most severe disease of boxwood, which can develop very quickly and is characterized by the following symptoms. The top of the bush fades, the lower part of the stem rots. Leaves lose color, become watery. Possible formation of a white coating. Black large growths appear on the surface of the stem – sclerotia of the fungus. They can also be seen in the cut of the escape.
The pathogen enters the plant from the soil through the lower part of the stems. The disease is especially active in conditions of high humidity, at a low temperature of 12 – 15 ° C. The spores of the fungus are spread by the wind.
To strengthen the plant and prevent its infection, it is recommended to use foliar top dressing:
- urea – 10 g;
- copper sulfate – 2 g;
- zinc sulfate – 2 g.
All components should be dissolved in 10 liters of water.
Cytosporosis or rotting boxwood burn
This is a very dangerous infectious disease of the plant bark. The affected areas become dry and begin to crack on the border with healthy ones. The bark is covered with a large number of dark tubercles containing inside the fungus that causes the disease. Damaged areas take on the appearance of “goosebumps”. Leaves and flowers dry up, but do not fall off for a long time.
In the case of penetration of the fungus into the deeper layers of the tree, gum flows out of the resulting cracks, the solidification of which leads to a violation of the conductivity of the boxwood vessels. The infection enters the plant through any violation of the integrity of the bark, regardless of the nature of their origin – wounds, cuts, scratches, cracks. The death of the branches occurs after 1 – 2 months. Gradually multiplying, the fungus covers an increasing area of uXNUMXbuXNUMXbthe bush and getting into the wood can lead to the death of the entire plant.
In the early stages of the disease, until the fungus has gone deep into the cortex, it is removed with a knife, leaving only healthy tissue. The remaining wounds are disinfected with 2% copper sulphate and covered with nigrol putty or garden pitch. Very large wounds are recommended to be additionally bandaged.
Root rot
This destructive process and many other painful conditions of boxwood can cause not only fungal pathogens and improper care. An ornamental plant does not like excessive soil moisture. Frequent watering, especially during the cold period, causes the root system to suffocate, overcool and rot. The plant ceases to receive moisture and nutrients in the required amount and, ultimately, dries up.
To prevent the occurrence of such a disease, in autumn and winter, watering boxwood should be reduced.
Boxwood pests and their control
In addition to the listed diseases, various boxwood pests that infect the plant cause a lot of trouble and trouble for gardeners. Ways to deal with them depend on their type and the degree of harm caused. The most common boxwood insects are:
Boxwood galitsa
When attacking boxwood, this mosquito-like parasite creates outgrowths that hide inside orange larvae no larger than 2,5 mm in size. Noticeable convex yellow spots appear on the leaves with swollen nodules in the lower part. The affected plant turns yellow very quickly and dies.
At the first symptoms of the appearance of gall midge, boxwoods are treated with Bitoxibacellin, Fufanon, Lightning, Actellik, Karbofos-500. Processing is carried out 2 – 3 times a week, from the second half of May to mid-June, during the appearance of insects from pupae.
Leaf flea (leaf flea)
This small yellow insect infects the leaves, causing them to swell, curl, arch in the form of a spoon and become covered with a white bloom. The sticky secretions of fleas form a waxy coating under which the larvae live. Pests feed on boxwood sap.
These insects can be controlled with insecticides. The affected foliage is removed, the boxwood is sprayed with mineral oil. In most cases, the damage caused by these psyllids does not cause significant harm to boxwood bushes.
spider mite
The spider mite is most common in areas characterized by a warm climate. It actively shows its effect in conditions of high temperature and dry air. Small insects no larger than 0,5 mm settle on the underside of the leaves. Boxwood branches are entangled in cobwebs. As a result of punctures by ticks, the leaves are first covered with small yellow specks, then discolor and die. The box is losing strength.
Spraying with chemicals such as Fufanon or Aktellik will help get rid of a large number of ticks. If there are few insects, they can be washed off with a soapy liquid prepared from 120 g of laundry soap and 4 liters of warm water. Then the boxwood should be treated with an oil spray.
Boxwood felt (worm)
Sucking insects called hairy lice are visible to the naked eye. They form whitish discharges on the veins and cuttings of leaves, similar to wax traces, in which colonies of these pests develop. The mealybugs lay numerous eggs wrapped in felt-like bags on the underside of the leaves. The period of active development falls on June and the second half of August. The foliage of the boxwood turns yellow, falls off. If timely protection measures are not taken, the death of the plant occurs after 2 to 3 years.
In order to combat felting, first of all, it is necessary to remove damaged branches and leaves of boxwood. Bushes are sprayed with mineral oils, which form an oil film. Insects suffocate under it and die. You can also treat boxwood with methyl bromide.
Boxwood Firing
The night butterfly brings the boxwood significant harm. Lemon-green caterpillars entwine the entire tree with thick cobwebs and feed on its foliage pulp. Leaves change their color. The bushes dry quickly, which is accompanied by an unpleasant odor.
Boxwood is sprayed with biological insecticides, depending on the level of development of the larvae. Not only the plant itself is processed, but also the soil around it within a radius of 40 – 50 cm. In the fight against boxwood moth, preparations such as Bi-58, Decis, Fastak, Sharpei, Vega, Atom, Fury have proven themselves well. These powerful drugs should be used with extreme caution. In the early stages of the disease, it is better to use Dimilin, an insecticide that is safe for humans and animals.
Shields (false shields)
Insects that look like white and golden brown bumps live on the surface of boxwood stems. Microscopic pests can often be picked off with a regular needle. You can also remove them with an old toothbrush. This method is completely safe for boxwood.
After processing, the stems are wiped with kerosene using a piece of cotton wool. The formed kerosene film leads to the fact that insects suffocate and die. Spraying the boxwood with an oil spray will restore the lost shine to the leaves. With a significant number of pests or when a large number of boxwood bushes are infected, it is better to treat the plantings with insecticides.
Gallic (four-legged) tick
When attacked by a pest, the kidneys and growing leaves of boxwood are damaged. They appear pubescent oblong outgrowths – galls, which creates the impression of their swelling. Although mites rarely cause significant harm to boxwood, they are difficult to control.
Treatment of the consequences of the influence of diseases and pests on the growth and health of boxwood takes quite a long time and requires some knowledge and skills. To prevent this, regular preventive measures are recommended.
Prevention of diseases and pests of boxwood
Under the influence of the attack of pests and the negative manifestation of various diseases, a beautiful ornamental boxwood plant can very quickly lose its strength and subsequently die. Timely implementation of some preventive measures will avoid such serious consequences.
The main measures to prevent the occurrence and development of boxwood diseases include:
- proper care – top dressing, pruning, treatment with drugs;
- disinfection of instruments;
- removal of damaged plant parts;
- maintaining a stable temperature and humidity level when growing decorative boxwood indoors.
Often the cause of plant diseases is an elementary non-compliance with the rules of care and growth. A change in the appearance of the bushes may signal the following:
- Drying and twisting of the leaves with a lack of moisture. Boxwood should be watered more often and more abundantly.
- Loss of intensity of green color in foliage – in case of excess sunlight. It is necessary to create shading conditions.
- The appearance of yellowness indicates a drop in low temperatures. The plant needs additional heating.
- The acquisition of a reddish tint by the leaves – with insufficient intake of nitrogen. Boxwood bushes should be fertilized regularly.
In the fight against pests and diseases of boxwood, you can take advantage of the influence of their natural opponents. Insects such as ladybugs, earwigs, predatory mites, hoverflies, lacewings, and others eat aphids and spores of the fungus. To attract these helpers to the garden, you should sow dill, mustard, phacelia, parsley, cilantro, cumin, plantain.
Compliance with the basic rules of care and the creation of favorable conditions for the growth and development of boxwood are the best means of preventing diseases and pests.
Conclusion
Having studied boxwood diseases, photos of pests and ways to deal with them, you can safely acquire this wonderful ornamental plant on your site. With proper care and original crown formation, it will make an unforgettable impression and delight the owners and guests of the garden plot with its appearance.
