Content
Hosta diseases can be fungal or viral in origin. Some ailments are very dangerous and cannot be treated, others can be quickly cured, but in any case, it is necessary to distinguish between their symptoms.
Causes and signs of host disease damage
Most often, hosta is affected by fungal diseases. The main reason is improper care of the plant. The development of fungi is especially promoted by:
- waterlogged and acidic soil;
- lack of mineral elements in the soil;
- excessive shading or excess sunlight;
- dense plantings, if the flower bed in which the hosta grows is too dense, the risk of disease increases;
- poor sanitary condition of the site and uncollected plant debris;
- poor ventilation and rare loosening of the soil.
In addition to fungi, ornamental crops can be affected by viruses. Such diseases are most often carried by insect pests.In addition, the virus can penetrate host tissue from the soil, for example, if a diseased plant previously grew on the site, and the site was not disinfected after it. In some cases, seedlings turn out to be sick even when planted; not all nurseries are able to guarantee the unconditional quality of the material.
Hosta may suffer from diseases and pests due to improper care
Symptoms of viral and fungal diseases are usually very similar. A gardener should be wary if:
- the leaves of the hosta begin to turn yellow, weaken and curl;
- the plant stops growing, loses its color saturation and does not bloom;
- leaf plates become covered with an unsightly coating or spots of light and dark color.
At the first symptoms, the decorative crop needs to be studied more carefully. This will allow us to determine what exactly she is sick with and begin treatment immediately.
Hosta diseases with photos and their treatment
Garden hosta can suffer from diseases of viral and fungal origin. To take the right control measures, you need to study photos and descriptions of diseases and learn to distinguish them from each other.
Rust
Rust is a fairly common disease of ornamental crops. It occurs most often in hot summers with insufficient watering. The disease is easily recognized by the reddish-brown spots that quickly cover the leaf blades and merge with each other. Under the influence of rust, the leaves begin to dry out and wither, which can lead to the death of the hosta.
When rust occurs, orange-brown spots appear on the leaves.
Rust control is carried out using fungicidal preparations, for example, Fundazol or Bordeaux mixture. In this case, the leaves affected by the disease must be removed.If the disease has not spread too much, then spraying can cope with it.
Crown Rot
The disease is characterized by yellowing and wilting of leaves from the outside to the center, which explains the name. The cause of yellowing is root rot - the diseased hosta stops receiving nutrition from the soil and quickly withers. The structure of the leaf plates may become loose, large leaves simply begin to tear away from the bush. In advanced cases, white threads of fungal mycelium become noticeable on the host.
When crown rot occurs, the host begins to turn yellow on the outside of the crown.
Crown rot is difficult to treat because the roots may be severely affected by the time symptoms appear. If the symptoms of the disease are mild, you can treat the hosta and the soil around its roots with fungicidal preparations. In case of severe damage, it is better to dig up the bush and destroy it before the fungus spreads to neighboring crops.
Phyllosticosis
A fungal disease leads to the appearance of brown spots on the leaf blades of a garden plant. Gradually, these spots merge with each other and completely cover the leaf, and a yellowish or whitish coating forms on top. Necrotic areas dry out and crumble, and the ornamental plant dies.
Phyllosticosis leaves brown spots, which are then covered with plaque
Phyllostictosis usually appears in conditions of waterlogging. To combat the disease, you need to treat the host with Abiga-Pik, Strobi or copper sulfate, and also reduce the frequency of watering.
Anthracnose
The common disease mainly affects hostas growing in shaded areas and moist soils. Anthracnose manifests itself as brown spots and dots with a dark border on the leaf blades.Gradually, the spots grow over the entire leaf, causing it to dry out, become deformed and fall off.
With anthracnose, brown spots with a dark border appear
To treat anthracnose, it is necessary to completely remove the affected leaf blades, and then spray the plantings with fungicidal agents - Fundazol or Bordeaux mixture. The area with hosts needs to be thinned out to ensure good ventilation. It is better to reduce watering; the appearance of anthracnose indicates that the soil is waterlogged.
Soft rot
A dangerous bacterial disease affects the hosta in the lower part and leads to decomposition of the stem and lower leaves. You can recognize a fungal disease by brown spots on the leaf blades and the characteristic putrid odor emanating from the hosta.
The disease most often appears in conditions of high humidity, in the presence of damage to the leaves and stems, as well as after the hosta freezes during spring frosts. Soft rot cannot be treated; the host affected by the disease will have to be completely removed from the site. After this, the tools must be thoroughly washed and disinfected, and the soil must be treated with formaldehyde, just in case.
With soft rot, the leaves and stem of the plant simply begin to decompose
Sclerotinia
The fungal disease begins to spread from the root collar of the bush. In this case, whitish threads resembling cotton wool fibers form on the surface of the stem in the lower part. The leaves of the hosta become covered with brown spots and begin to die; black sclerotia gradually appear at the site of the plaque.
Sclerotinia can be easily recognized by whitish threads on the stem
Sclerotinia is a dangerous disease that cannot be cured. The affected host can only be removed from the site and the soil in which it grew is treated so that the disease does not affect other plantings.
Gray rot
The disease can be recognized by the appearance of an ashy coating on the leaves. As the disease progresses, the leaves begin to rot and the tops dry out. Ultimately, the affected parts of the plant die, the hosta stops growing and withers. Gray rot spreads quickly and, if left untreated, invades neighboring crops.
Gray rot leaves a whitish coating on the leaf blades
In case of mild damage, you can treat the host with Fundazol or Ridomil Gold, after cutting off all affected areas. If the plant is seriously infected, it is better to dig it up and burn it.
Tobacco rattle virus
The incurable viral disease poses a serious threat to many crops, vegetables, flowering perennials and hostas. When infected, the crop stops growing, its shoots and leaves become deformed, and necrotic spots and speckled areas appear on the leaf blades. It is impossible to cope with the virus; the plant affected by the disease can only be eliminated.
The rattle virus leaves light spots and mosaics on leaf blades
The rattle of tobacco is dangerous because it easily spreads to other plants through the soil and uncleaned tools. Therefore, after removing the hosta from the soil, you need to thoroughly disinfect both the soil and the pruning shears or knife with which the plant was cut.
Leaf curl virus
Leaf curl is a viral disease that especially often affects tomatoes, but the host also suffers from it.The infection disrupts the growth functions of the plant, the leaves become wrinkled and deformed, tear in some places, and become covered with small star-shaped spots. In the later stages of the disease, necrotic areas appear at the site of these spots, which quickly fall out of the leaf tissue.
From the curl virus, the leaf plates are deformed and covered with an uneven light pattern
There is no treatment for viral curl, so the hosta can only be removed from the area. After this, the soil should be disinfected and other plants should be closely monitored in the future.
Virus X (HVX)
Hosta virus X, or HVX, is a dangerous disease specific to this garden crop. It was discovered in 1996, and its symptoms are very similar to those of other viral mosaics. When infected with virus X, the leaves of the plant begin to curl, specks and mosaics appear on them, and the plant dies over time.
The mosaic virus causes the host to lighten unevenly and begin to curl
At the first symptoms of the virus, the host needs to be removed from the flowerbed and burned, and then not only the soil, but also tools and even work clothes should be disinfected. Virus X is very easily transmitted to other plants along with the remaining sap of an infected specimen.
Hosta pests and methods of controlling them
For hostas in the garden, not only fungi, but also harmful insects pose a danger. Parasites can cause just as much damage to a flower bed, but most of them can be successfully combated.
Foliar nematodes
Small nematode worms can infect both the root system of plants and the above-ground parts, but on the host they are usually localized specifically in the leaves. You can recognize the presence of worms by the characteristic dark stripes on the stems and leaves, indicating the path of movement of the pest from the roots.
You can recognize the presence of nematodes by their characteristic brown stripes.
Nematodes are one of the few pests for which there is no cure yet. The affected hosta bush is simply burned, and then the soil and garden tools are disinfected.
Snails
Large garden hostas often attract the attention of snails. Gastropods capture the leaf blades of the plant and feed on the greens and stems. If you do not start the fight in time, the snails will be able to completely eat the hosta bush to the very root.
Snails can seriously eat a garden plant
Since snails overwinter in the soil, in the spring it is recommended to loosen the soil at the roots of the hosta and replace its top layer. During the warm season, the leaves of the plant should be inspected regularly. Detected snails are removed manually; if there are a large number of insects, you can spray the host with a soap solution.
Beetles
Decorative hosta can suffer from beetles, and especially from weevils, which pose a threat to roots and leaves. The beetle larvae develop in the soil and eat the roots of the plant, while the adult pest feeds on the stems and leaf blades. The beetle looks like a large insect up to 10 cm long with a dark shell.
Beetles leave holes on hosta leaves
You can recognize the presence of beetles by the appearance of semicircular holes along the edges of the leaf blades. The pest most often attacks hostas on dry and poor soils.If the host is infested with beetles, it should be immediately sprayed with an insecticidal solution, for example, Aktellik or Aktara, and the entire flowerbed should be treated.
Caterpillars
No less dangerous for ornamental plants are butterfly caterpillars that feed on hosta juices. It is easy to recognize the caterpillars; as a result of their vital activity, through holes and uneven grooves on the edges appear on the leaves. Hosta buds and flowers suffer during the flowering period.
Caterpillars actively feed on the green mass of the hosta
If the infestation is small, you can collect the caterpillars manually, or they can simply be washed off the leaves with a stream of water. If there are a lot of pests, then the host needs to be treated with Karbofos, Intavir and other means.
Rodents
Hosta is a fairly large garden plant. Therefore, it often attracts the attention of rodents - mice, rats and others. Rodents damage the roots and thick stems of the plant, which leads to the death of the plantings. You can recognize the appearance of pests by characteristic damage in the lower part of the stem and by impaired growth.
For decorative hosta, not only insects, but also rodents are dangerous
Rodent control is usually carried out using poisonous baits - granules are scattered under bushes. For the winter, the pruned plant must be densely mulched with compost or peat. If there are pets on the property, it is important to ensure that they do not accidentally eat the poison intended for rats and mice.
Slugs
Gastropods feed on the green parts of the plant and especially often attack hostas with thin leaves, young specimens and dwarf varieties.You can recognize the presence of slugs by the silvery stripes on the leaves - the pests leave a characteristic trail behind them as they move. Also, through holes in the leaves of the plant indicate infection with slugs.
Slugs often attack low varieties and young plants
To get rid of slugs, you need to scatter Thunderstorm bait or Methylaldehyde under the bushes, and lay moistened sheets of plywood on the flower bed at night. The next day, the caught pests can be collected and destroyed.
Prevention measures
The fight against diseases and pests is not only about treatment. First of all, you need to follow the basic rules of prevention - they will help, in principle, to avoid most problems:
- The soil at the roots of the hosta should not be waterlogged. It is necessary to adhere to moderate watering, because in swampy conditions fungal diseases spread especially quickly.
- Every year the host needs to be fed with complex mineral fertilizers. A balanced soil composition strengthens the plant's endurance and reduces the risk of infection by viruses and fungi.
- In autumn, the area with ornamental crops must be thoroughly cleaned. All plant debris is collected from the ground, taken to the far corner of the garden and destroyed, since it is under fallen leaves that larvae and fungal spores usually overwinter. For the same reason, it is recommended to prune the hosta in the winter; dangerous bacteria can develop under the plant’s own wilted leaves.
- Hosta plantings should not be overly thickened. Plants growing nearby must receive sufficient light and fresh air, otherwise the risk of developing fungal diseases will greatly increase.
To prevent the host from suffering from diseases, you need to keep the area clean
To save the hosta from fungal diseases and viruses, it is recommended to carry out annual preventive spraying. At the beginning of spring, the flower bed is treated with Bordeaux mixture or any fungicidal agent according to the instructions, then the treatment is repeated twice more with intervals of 15-20 days. If there are fungal spores in the soil near the roots, then with timely prevention they simply will not be able to develop and manifest characteristic symptoms.
As for pests, insecticide spraying is usually carried out after the presence of insects becomes obvious. For preventive purposes, it is recommended to regularly loosen the soil and annually replace its top layer, in which the larvae usually hide.
Conclusion
Hosta diseases in a neglected state can quickly destroy an ornamental plant. But if you notice the symptoms in time and begin treatment, then most ailments can be dealt with.
