文章
Dummer. ゛☀
2017年09月13日
Water-soaked lesions between the veins of leaves are a telltale symptom of this bacterial disease, which infects cucumbers, summer squash, and melons. Symptoms often first appear on the underside of leaves. As infected areas in the leaf die, the tissue becomes brittle and those leaf parts fall away, giving afflicted leaves a ragged appearance. Angular leaf spot lesions may exude a milky fluid that dries on leaf surfaces. In severe outbreaks, lesions may also develop on stems and fruit.
The bacterium overwinters in the soil on seeds and plant residues, and is spread by rain splash and wind. Angular leaf spot is especially prevalent in warm, humid climates.
Prevention and Control
Plant vegetable varieties that are well-suited to your particular climate, and when possible, choose varieties such as Olympian cucumber that are resistant to angular leaf spot.
Practice a two- or three-year crop rotation of cucumbers and other squash-family crops to break the disease cycle.
Prevent the spread of disease by destroying infected plants and any that are in close proximity to them.
Splashing water spreads bacteria. Avoid overhead watering and use drip irrigation or soaker hoses to keep foliage as dry as possible. Avoid working in garden when plants are wet.
Avoid overfertilizing; excess nitrogen produces tender growth that is more vulnerable to infection
The bacterium overwinters in the soil on seeds and plant residues, and is spread by rain splash and wind. Angular leaf spot is especially prevalent in warm, humid climates.
Prevention and Control
Plant vegetable varieties that are well-suited to your particular climate, and when possible, choose varieties such as Olympian cucumber that are resistant to angular leaf spot.
Practice a two- or three-year crop rotation of cucumbers and other squash-family crops to break the disease cycle.
Prevent the spread of disease by destroying infected plants and any that are in close proximity to them.
Splashing water spreads bacteria. Avoid overhead watering and use drip irrigation or soaker hoses to keep foliage as dry as possible. Avoid working in garden when plants are wet.
Avoid overfertilizing; excess nitrogen produces tender growth that is more vulnerable to infection
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Dummer. ゛☀
2017年09月03日
Willow scab disease attacks different types of willow species in Europe and the United States. It can attack weeping willows but is not one of the more common weeping willow diseases. Willow scab is caused by the fungus Venturia salciperda. Scab on willow trees usually doesn’t cause serious harm unless the black canker fungus (Glomerella miyabeanais) is also present. Read on to learn about how to recognize and how to treat willow scab.
Scab on Willow Trees
Willow scab is a fungal disease that causes leaf symptoms, followed by brown spore masses at the base of leaves. The symptoms of scab on willow start with dark spots on the leaves. These can be brown or black, and cause the leaves to wilt, shrivel up and die.
In time, as the willow scab disease progresses, the fungus spreads to the stem tissue at the bases of leave petioles. There, it forms olive-brown velvety spore masses. This happens most often in wet spring weather. Look on the underside of the leaves and along the rib and veins for these fruiting bodies. Although scab on willow trees can attack any almost any Salix tree, it is not considered one of the common weeping willow diseases. In fact, weeping willows (Salix babylonica) are the most resistant willow species to this disease.
How to Treat Willow Scab
Willow scab disease causes only minor damage to your trees if they are healthy. However, repeated infections may slow a willow’s growth and reduce its vigor. If you are wondering about whether effective willow scab treatment exists, you’ll be happy to hear that it does. You can control willow scab on your backyard willows with a combination of good cultural practices and chemical applications. How to treat willow scab with cultural practices? First, you’ll need to trim out all of the infected parts of the willow tree, including stems and twigs. Don’t forget to sterilize your pruners with a bleach and water mixture to avoid spreading the fungus.
In addition, keep your trees vigorous with sufficient irrigation and regular fertilizer. The disease does much less damage to healthy trees than vulnerable ones. Finally, properly timed fungicide applications can be part of your willow scab treatment. This is especially important if your tree is also infected by the black canker fungus.
Scab on Willow Trees
Willow scab is a fungal disease that causes leaf symptoms, followed by brown spore masses at the base of leaves. The symptoms of scab on willow start with dark spots on the leaves. These can be brown or black, and cause the leaves to wilt, shrivel up and die.
In time, as the willow scab disease progresses, the fungus spreads to the stem tissue at the bases of leave petioles. There, it forms olive-brown velvety spore masses. This happens most often in wet spring weather. Look on the underside of the leaves and along the rib and veins for these fruiting bodies. Although scab on willow trees can attack any almost any Salix tree, it is not considered one of the common weeping willow diseases. In fact, weeping willows (Salix babylonica) are the most resistant willow species to this disease.
How to Treat Willow Scab
Willow scab disease causes only minor damage to your trees if they are healthy. However, repeated infections may slow a willow’s growth and reduce its vigor. If you are wondering about whether effective willow scab treatment exists, you’ll be happy to hear that it does. You can control willow scab on your backyard willows with a combination of good cultural practices and chemical applications. How to treat willow scab with cultural practices? First, you’ll need to trim out all of the infected parts of the willow tree, including stems and twigs. Don’t forget to sterilize your pruners with a bleach and water mixture to avoid spreading the fungus.
In addition, keep your trees vigorous with sufficient irrigation and regular fertilizer. The disease does much less damage to healthy trees than vulnerable ones. Finally, properly timed fungicide applications can be part of your willow scab treatment. This is especially important if your tree is also infected by the black canker fungus.
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文章
Dummer. ゛☀
2017年09月02日
Ganodera palm disease, also called ganoderma butt rot, is a white rot fungus that causes palm tree trunk diseases. It can kill palm trees. Ganoderma is caused by the pathogen Ganoderma zonatum, and any palm tree can come down with it. However, little is known about the environmental conditions that encourage the condition. Read on for information about ganoderma in palms and good ways of dealing with ganoderma butt rot.
Ganoderma in Palms
Fungi, like plants, are divided into genera. The fungal genus Ganoderma contains different wood-decaying fungi found around the world on almost any type of wood, including hard wood, soft wood and palms. These fungi can result in ganoderma palm disease or other palm tree trunk diseases.
The first sign you are likely to have when ganoderma palm disease has infected your palm is the conk or basidiocarp that forms on the side of a palm trunk or stump. It appears as a soft, but solid, white mass in a circular shape lying flat against the tree.
As the conk matures, it grows into a shape that resembles a little, half-moon-shaped shelf and it turns partially gold. As it gets old, it darkens even more into brown shades, and even the base of the shelf is no longer white. The conks produce spores that experts believe are the primary means of spreading this ganoderma in palms. It is also possible, however, that pathogens found in the soil are capable of spreading this and other palm tree trunk diseases.
Ganoderma Palm Disease
Ganoderma zonatum produces enzymes that cause the ganoderma palm disease. They rot or degrade woody tissue in the lower five feet of the palm trunk. In addition to the conks, you may see a general wilting of all of the leaves in the palm other than the spear leaf. The tree growth slows and the palm fronds turn off color. Scientists cannot say, as yet, how long it takes before a tree infected with Ganoderma zanatum produces a conk. However, until a conk appears, it is not possible to diagnose a palm as having ganoderma palm disease. That means that when you plant a palm in your yard, there is no way for you to be sure that it is not already infected by the fungus.
No pattern of cultural practices has been associated with the development of this disease. Since the fungi only appears on the lower segment of the trunk, it is not related to improper pruning of the fronds. At this time, the best recommendation is to watch for signs of ganoderma in palms and remove a palm if conks appear on it.
Ganoderma in Palms
Fungi, like plants, are divided into genera. The fungal genus Ganoderma contains different wood-decaying fungi found around the world on almost any type of wood, including hard wood, soft wood and palms. These fungi can result in ganoderma palm disease or other palm tree trunk diseases.
The first sign you are likely to have when ganoderma palm disease has infected your palm is the conk or basidiocarp that forms on the side of a palm trunk or stump. It appears as a soft, but solid, white mass in a circular shape lying flat against the tree.
As the conk matures, it grows into a shape that resembles a little, half-moon-shaped shelf and it turns partially gold. As it gets old, it darkens even more into brown shades, and even the base of the shelf is no longer white. The conks produce spores that experts believe are the primary means of spreading this ganoderma in palms. It is also possible, however, that pathogens found in the soil are capable of spreading this and other palm tree trunk diseases.
Ganoderma Palm Disease
Ganoderma zonatum produces enzymes that cause the ganoderma palm disease. They rot or degrade woody tissue in the lower five feet of the palm trunk. In addition to the conks, you may see a general wilting of all of the leaves in the palm other than the spear leaf. The tree growth slows and the palm fronds turn off color. Scientists cannot say, as yet, how long it takes before a tree infected with Ganoderma zanatum produces a conk. However, until a conk appears, it is not possible to diagnose a palm as having ganoderma palm disease. That means that when you plant a palm in your yard, there is no way for you to be sure that it is not already infected by the fungus.
No pattern of cultural practices has been associated with the development of this disease. Since the fungi only appears on the lower segment of the trunk, it is not related to improper pruning of the fronds. At this time, the best recommendation is to watch for signs of ganoderma in palms and remove a palm if conks appear on it.
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文章
Dummer. ゛☀
2017年09月02日
Fusarium wilt is a common disease of ornamental trees and shrubs. Palm tree Fusarium wilt comes in different forms but is recognizable by similar symptoms. Fusarium wilt in palm trees is host specific and has no cure. The end result in untreated palms is death. Learn how to treat Fusarium wilt in palms with a careful management program. If nothing else, careful hygiene and cultural practices can extend the life of the tree.
Causes of Palm Tree Fusarium Wilt
Fusarium wilt is caused by the fungus Fusarium oxysporum. The two main strains are Fusarium oxysporum f. sp. Canariensis, which only attacks Canary palms, and Fusarium oxysporum f. sp. Palmarum, which is found in several ornamental palms.
The disease does the most damage in plants that are in dry regions. Plants growing in cooler, wetter areas will still show symptoms but decline and die more slowly. As a rule, plants with Fusarium wilt of palms should be removed but this is a big chore in some cases. There is no Fusarium wilt treatment for palms and the disease is contagious and can infect other plants nearby.
The fungus responsible for Fusarium wilt in palm trees can persist in soil for years. Spores enter plants through the roots and travel into the vascular system. Fusarium attacks the xylem, reducing water uptake. Over time it closes up the water collecting tissue with a sticky substance that the fungus produces. Gradually, the tree will show signs of stress due to inadequate water. The pathogen can also spread through mechanical means. The most common ways plants are infected is from contaminated purchased trees and from unsanitary pruning practices. Tools with the pathogen on them can introduce it during cutting. It is, therefore, extremely important to sanitize tools before using them on another plant.
Symptoms of Fusarium Wilt of Palms
Because water introduction is interrupted, the fronds or leaves of the tree are the first to display signs of infection. Just as any plant’s leaves will droop and discolor when there is too little moisture, the fronds will turn yellow and finally brown, crinkle at the ends of leaflets and eventually die. The effect usually starts at the lower or older fronds and moves up the palm. A companion disease, called pink rot, hastens the dying process in many cases. It is an opportunistic fungus which only attacks old, weak or injured plants. Fusarium wilt treatment for palms must, therefore, start with an application of Thiophanate-methyl fungicide to stem the march of pink rot.
How to Treat Fusarium Wilt
Because there is no cure for the disease, the only course of action is careful management of the tree, unless you elect to remove it entirely. Provide supplemental water and clean up infected debris immediately. Do not try to compost infected material, as spores can still survive and infest your compost heap. Prune off dying fronds but disinfect tools before using them on other plants. Do not use a chainsaw and trim on a windless day to prevent infected sawdust from drifting over to healthy specimens.
Hygiene is one of the most important facets of Fusarium wilt treatment for palms. Good water and nutrient sources for the tree can prolong its life for several years.
Causes of Palm Tree Fusarium Wilt
Fusarium wilt is caused by the fungus Fusarium oxysporum. The two main strains are Fusarium oxysporum f. sp. Canariensis, which only attacks Canary palms, and Fusarium oxysporum f. sp. Palmarum, which is found in several ornamental palms.
The disease does the most damage in plants that are in dry regions. Plants growing in cooler, wetter areas will still show symptoms but decline and die more slowly. As a rule, plants with Fusarium wilt of palms should be removed but this is a big chore in some cases. There is no Fusarium wilt treatment for palms and the disease is contagious and can infect other plants nearby.
The fungus responsible for Fusarium wilt in palm trees can persist in soil for years. Spores enter plants through the roots and travel into the vascular system. Fusarium attacks the xylem, reducing water uptake. Over time it closes up the water collecting tissue with a sticky substance that the fungus produces. Gradually, the tree will show signs of stress due to inadequate water. The pathogen can also spread through mechanical means. The most common ways plants are infected is from contaminated purchased trees and from unsanitary pruning practices. Tools with the pathogen on them can introduce it during cutting. It is, therefore, extremely important to sanitize tools before using them on another plant.
Symptoms of Fusarium Wilt of Palms
Because water introduction is interrupted, the fronds or leaves of the tree are the first to display signs of infection. Just as any plant’s leaves will droop and discolor when there is too little moisture, the fronds will turn yellow and finally brown, crinkle at the ends of leaflets and eventually die. The effect usually starts at the lower or older fronds and moves up the palm. A companion disease, called pink rot, hastens the dying process in many cases. It is an opportunistic fungus which only attacks old, weak or injured plants. Fusarium wilt treatment for palms must, therefore, start with an application of Thiophanate-methyl fungicide to stem the march of pink rot.
How to Treat Fusarium Wilt
Because there is no cure for the disease, the only course of action is careful management of the tree, unless you elect to remove it entirely. Provide supplemental water and clean up infected debris immediately. Do not try to compost infected material, as spores can still survive and infest your compost heap. Prune off dying fronds but disinfect tools before using them on other plants. Do not use a chainsaw and trim on a windless day to prevent infected sawdust from drifting over to healthy specimens.
Hygiene is one of the most important facets of Fusarium wilt treatment for palms. Good water and nutrient sources for the tree can prolong its life for several years.
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文章
Dummer. ゛☀
2017年09月02日
Lethal yellowing is a tropical disease that affects several species of palm. This disfiguring disease can devastate landscapes in South Florida that rely on palms. Find out about lethal yellowing treatment and detection in this article.
What is Lethal Yellowing?
As the name implies, lethal yellowing is a fatal disease. It is caused by a phytoplasma, which is a microscopic organism a little less sophisticated than a bacteria. Insects called planthoppers carry the phytoplasma from tree to tree. Planthoppers can’t survive at temperatures below freezing, and this prevents the disease from spreading into other parts of the country. Lethal yellowing disease can’t be controlled by killing the insect vector because insecticides often fail to come into contact with these constantly moving, flying insects. Lethal yellowing disease affects coconut palms, date palms, and a few other palm species. In the U.S., it occurs in the lower third of the state of Florida where temperatures never drop below freezing. Palm trees in some parts of the Caribbean, as well as Central and South America, may also suffer from the disease. There is no cure, but you can extend the life of your tree and prevent lethal yellowing from spreading.
Treating or Preventing Lethal Yellowing of Palms
Before you embark or a campaign to control leafhoppers and planthoppers, make sure you have lethal yellowing and not a less severe disease with similar symptoms. The symptoms of lethal yellowing appears in these three stages:
In the first stage, the nuts fall from the trees prematurely. Fallen nuts have a blackened or browned area near the point where they were attached to the stem. The second stage affects the tips of the male flowers. All new male flowers blacken from the tips down and then die. The tree can’t set fruit. The disease derives its name from the third stage where the fronds turn yellow. Yellowing begins with the lower fronds and advances toward the top of the tree. Trees infected with lethal yellowing disease should be removed and replaced with a resistant species. Consider planting native varieties, which have a natural resistance to the protoplasm. Taking the tree down as soon as you detect the disease helps prevent the spread to other trees.
When trees are rare or valuable, they can be injected with antibiotics. This is an expensive treatment, and the antibiotics are only available to professional arborists in the lower third of the state of Florida. Injections are only used as part of a broader control plan that includes the eventual replacement of the tree. Do not eat coconuts collected from treated palms.
What is Lethal Yellowing?
As the name implies, lethal yellowing is a fatal disease. It is caused by a phytoplasma, which is a microscopic organism a little less sophisticated than a bacteria. Insects called planthoppers carry the phytoplasma from tree to tree. Planthoppers can’t survive at temperatures below freezing, and this prevents the disease from spreading into other parts of the country. Lethal yellowing disease can’t be controlled by killing the insect vector because insecticides often fail to come into contact with these constantly moving, flying insects. Lethal yellowing disease affects coconut palms, date palms, and a few other palm species. In the U.S., it occurs in the lower third of the state of Florida where temperatures never drop below freezing. Palm trees in some parts of the Caribbean, as well as Central and South America, may also suffer from the disease. There is no cure, but you can extend the life of your tree and prevent lethal yellowing from spreading.
Treating or Preventing Lethal Yellowing of Palms
Before you embark or a campaign to control leafhoppers and planthoppers, make sure you have lethal yellowing and not a less severe disease with similar symptoms. The symptoms of lethal yellowing appears in these three stages:
In the first stage, the nuts fall from the trees prematurely. Fallen nuts have a blackened or browned area near the point where they were attached to the stem. The second stage affects the tips of the male flowers. All new male flowers blacken from the tips down and then die. The tree can’t set fruit. The disease derives its name from the third stage where the fronds turn yellow. Yellowing begins with the lower fronds and advances toward the top of the tree. Trees infected with lethal yellowing disease should be removed and replaced with a resistant species. Consider planting native varieties, which have a natural resistance to the protoplasm. Taking the tree down as soon as you detect the disease helps prevent the spread to other trees.
When trees are rare or valuable, they can be injected with antibiotics. This is an expensive treatment, and the antibiotics are only available to professional arborists in the lower third of the state of Florida. Injections are only used as part of a broader control plan that includes the eventual replacement of the tree. Do not eat coconuts collected from treated palms.
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文章
Dummer. ゛☀
2017年09月02日
Pink rot fungus, also known as Gliocladium blight, is a palm tree disease that infects damaged or weakened palms. Like many fungi, it is easier to prevent than it is to treat. Here are some tips on dealing with pink rot on palms.
Pink Rot Fungus in Palms
You won’t see a healthy, robust palm tree planted in just the right place with pink rot fungus. Called an opportunistic fungus, pink rot likes to invade a plant that is already weakened by poor conditions or injuries. Here are a few situations that can lead to pink rot on palms:
Palms that don’t get the right amount of sunlight
Palms planted to deeply or not deeply enough
Soil that is wet, poorly drained or compacted
Too much, too little or the wrong type of fertilizer
Cold weather damage
Palms poorly suited to the area
In addition to these environmental conditions, wounds can leave a palm susceptible to pink rot. Pruning away old leaves too soon creates a wound that serves as an entry point for disease. Remove leaf bases during warm, dry weather and only if they come away easily. Wounds caused by freeze damage and landscape maintenance injuries can also lead to pink rot.
Preventing Pink Rot Disease in Palm Trees
Make sure the soil drains freely before planting palms. To test the soil drainage, dig a hole about a foot deep and fill it with water. Let the water drain completely and then immediately fill it again. The water level should drop between one and six inches per hour. Will the palm get the right amount of sunlight in the proposed site? The amount of sunlight or shade the tree needs depends on the species, so check the growing information on the plant tag. If the tree isn’t just right for the location you have in mind, consider another type of palm or a different site.
Fertilize palm trees with a special fertilizer designed for palms. Palm fertilizers contain the high concentrations of trace elements that palms need. Follow the package instructions regarding the amount of fertilizer to use and the frequency. Make sure your climate is right for the palm you choose. If temperatures drop too low for the species, the resulting injury can encourage pink rot. A local nursery can help you find the right palm for your area.
Treating Palms with Pink Rot
The first step in treating the disease is to correct the stress condition that brought it on. If you can’t change the condition in the tree’s current location, you’ll have to decide whether you are willing to continue battling pink rot. If not, you may have no choice but to remove the tree and replace it with one better suited to the location. There are a couple of fungicides that can help treat pink rot disease in palm trees. You should consider fungicides a temporary measure to help restore the tree while you correct the cultural conditions. Look for fungicide treatments containing thiophanate methyl and mancozeb.
Follow the label instructions and use these pink rot palm treatments on the area of infection. You can also use them as a preventative measure to treat wounds and after pruning.
Pink Rot Fungus in Palms
You won’t see a healthy, robust palm tree planted in just the right place with pink rot fungus. Called an opportunistic fungus, pink rot likes to invade a plant that is already weakened by poor conditions or injuries. Here are a few situations that can lead to pink rot on palms:
Palms that don’t get the right amount of sunlight
Palms planted to deeply or not deeply enough
Soil that is wet, poorly drained or compacted
Too much, too little or the wrong type of fertilizer
Cold weather damage
Palms poorly suited to the area
In addition to these environmental conditions, wounds can leave a palm susceptible to pink rot. Pruning away old leaves too soon creates a wound that serves as an entry point for disease. Remove leaf bases during warm, dry weather and only if they come away easily. Wounds caused by freeze damage and landscape maintenance injuries can also lead to pink rot.
Preventing Pink Rot Disease in Palm Trees
Make sure the soil drains freely before planting palms. To test the soil drainage, dig a hole about a foot deep and fill it with water. Let the water drain completely and then immediately fill it again. The water level should drop between one and six inches per hour. Will the palm get the right amount of sunlight in the proposed site? The amount of sunlight or shade the tree needs depends on the species, so check the growing information on the plant tag. If the tree isn’t just right for the location you have in mind, consider another type of palm or a different site.
Fertilize palm trees with a special fertilizer designed for palms. Palm fertilizers contain the high concentrations of trace elements that palms need. Follow the package instructions regarding the amount of fertilizer to use and the frequency. Make sure your climate is right for the palm you choose. If temperatures drop too low for the species, the resulting injury can encourage pink rot. A local nursery can help you find the right palm for your area.
Treating Palms with Pink Rot
The first step in treating the disease is to correct the stress condition that brought it on. If you can’t change the condition in the tree’s current location, you’ll have to decide whether you are willing to continue battling pink rot. If not, you may have no choice but to remove the tree and replace it with one better suited to the location. There are a couple of fungicides that can help treat pink rot disease in palm trees. You should consider fungicides a temporary measure to help restore the tree while you correct the cultural conditions. Look for fungicide treatments containing thiophanate methyl and mancozeb.
Follow the label instructions and use these pink rot palm treatments on the area of infection. You can also use them as a preventative measure to treat wounds and after pruning.
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文章
Dummer. ゛☀
2017年09月02日
It’s a beautiful thing when a landscape comes together, even if it takes many years for your plants to mature into your dream garden. Sadly, many problems can interfere with gardening goals, including oak wilt disease, a serious fungal disease of oak trees. In some areas, oak wilt is becoming endemic, affecting both young and mature oak trees. Read on to learn about this important disease of oaks.
What is Oak Wilt?
Oak wilt is a serious disease of oak trees, caused by the fungal pathogen Ceratocystis fagacearum, which is believed to be native. It can be spread by boring beetles or through root-to-root contact between trees. The fungus grows in the transport tissues of infected trees, making it highly communicable between trees that are sharing connections in their root systems. Red and black oaks are considered highly susceptible to oak wilt, and may die completely within four months of initial infection. White oaks are more tolerant, often displaying only vague symptoms of oak wilt disease, if they show any at all. These oaks also eventually succumb to oak wilt, but may linger up to seven years.
How to Diagnose Oak Wilt
Oak wilt disease can be difficult to diagnose without professional help because the symptoms are similar to those found in other diseases, such as anthracnose, boring beetles, lightening damage and a myriad of environmental stressors. If your tree is suddenly showing yellowing or browning of the leaves of entire branches and is shedding leaves with significant areas of green remaining, it’s a good idea to cut a wilted branch or two across the grain. Dark circles in the otherwise lighter inner tissues are a good indicator that you need help, and fast.
Oak wilt treatment and prevention is serious business, requiring the use of heavy equipment to break your tree’s connection to any other oaks within 50 feet. Fungicidal injections of propiconazole have shown some promise in uninfected trees in high risk areas, but this treatment will do little for trees with oak wilt fungus in their root systems.
Minimize the risk to your tree from beetle-spread oak wilt spores by pruning only during the winter and painting all wounds with a latex paint as soon as they happen. Bark beetles often find damaged trees within the first three days, attracted by the scent of fresh sap – your timing is vital. Oak wilt is bad enough, but the addition of bark beetles may create a situation that’s hopeless for your tree.
What is Oak Wilt?
Oak wilt is a serious disease of oak trees, caused by the fungal pathogen Ceratocystis fagacearum, which is believed to be native. It can be spread by boring beetles or through root-to-root contact between trees. The fungus grows in the transport tissues of infected trees, making it highly communicable between trees that are sharing connections in their root systems. Red and black oaks are considered highly susceptible to oak wilt, and may die completely within four months of initial infection. White oaks are more tolerant, often displaying only vague symptoms of oak wilt disease, if they show any at all. These oaks also eventually succumb to oak wilt, but may linger up to seven years.
How to Diagnose Oak Wilt
Oak wilt disease can be difficult to diagnose without professional help because the symptoms are similar to those found in other diseases, such as anthracnose, boring beetles, lightening damage and a myriad of environmental stressors. If your tree is suddenly showing yellowing or browning of the leaves of entire branches and is shedding leaves with significant areas of green remaining, it’s a good idea to cut a wilted branch or two across the grain. Dark circles in the otherwise lighter inner tissues are a good indicator that you need help, and fast.
Oak wilt treatment and prevention is serious business, requiring the use of heavy equipment to break your tree’s connection to any other oaks within 50 feet. Fungicidal injections of propiconazole have shown some promise in uninfected trees in high risk areas, but this treatment will do little for trees with oak wilt fungus in their root systems.
Minimize the risk to your tree from beetle-spread oak wilt spores by pruning only during the winter and painting all wounds with a latex paint as soon as they happen. Bark beetles often find damaged trees within the first three days, attracted by the scent of fresh sap – your timing is vital. Oak wilt is bad enough, but the addition of bark beetles may create a situation that’s hopeless for your tree.
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文章
Dummer. ゛☀
2017年09月02日
Sudden oak death is a deadly disease of oak trees in coastal areas of California and Oregon. Once infected, trees can’t be saved. Find out how to protect oak trees in this article.
What is Sudden Oak Death?
The fungus that causes sudden oak death (Phytophthora ramorum) results in a quick death for tanoaks, California black oaks, and live oaks along the coast of California and Oregon. The fungus also infects the following landscape plants:
Bay laurel
Huckleberry
California buckeye
Rhododendron
Here are the symptoms of sudden oak death:
Cankers on the stems and branches. Leaves in the crown that turn pale green, then yellow, then brown. Cankers that bleed and ooze. In the alternative species, it causes non-fatal leaf spot or twig dieback instead of the bleeding cankers it causes in oaks. Sudden oak death can infect other species of oak, but those species don’t grow in habitats where the fungus is found, so for now, it isn’t a problem. Since P. ramorum has been identified in nursery stock in California, Oregon and Washington, there is a possibility of the disease spreading to other parts of the country.
Sudden Oak Death Information
This disease is always fatal in susceptible oak species and there is no cure. Sudden oak death treatment focuses on prevention and protection. Here are a few things you can do to protect your susceptible oaks:
Allow 15 feet between the trunk of an oak tree and other susceptible species, such as bay laurel and rhododendron. Spray the fungicide Agri-fos to protect oak trees. This is a preventative spray, not a cure. Don’t plant new oak trees in areas with known infection.
What is Sudden Oak Death?
The fungus that causes sudden oak death (Phytophthora ramorum) results in a quick death for tanoaks, California black oaks, and live oaks along the coast of California and Oregon. The fungus also infects the following landscape plants:
Bay laurel
Huckleberry
California buckeye
Rhododendron
Here are the symptoms of sudden oak death:
Cankers on the stems and branches. Leaves in the crown that turn pale green, then yellow, then brown. Cankers that bleed and ooze. In the alternative species, it causes non-fatal leaf spot or twig dieback instead of the bleeding cankers it causes in oaks. Sudden oak death can infect other species of oak, but those species don’t grow in habitats where the fungus is found, so for now, it isn’t a problem. Since P. ramorum has been identified in nursery stock in California, Oregon and Washington, there is a possibility of the disease spreading to other parts of the country.
Sudden Oak Death Information
This disease is always fatal in susceptible oak species and there is no cure. Sudden oak death treatment focuses on prevention and protection. Here are a few things you can do to protect your susceptible oaks:
Allow 15 feet between the trunk of an oak tree and other susceptible species, such as bay laurel and rhododendron. Spray the fungicide Agri-fos to protect oak trees. This is a preventative spray, not a cure. Don’t plant new oak trees in areas with known infection.
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文章
Dummer. ゛☀
2017年08月31日
Hemlock trees are a popular conifer that is commonly used as either privacy shrubs or as visual anchor trees in the landscape. Most of the time, pruning hemlocks is not necessary, but occasionally weather damage, disease or competing main trunks on upright hemlocks can create the need for pruning hemlocks. Keep reading to learn how and when to prune hemlocks.
When to Prune Hemlocks
If you find that you need to prune your hemlock tree, the best time for trimming hemlocks is in either spring or early summer. At this time, the tree is getting ready for or is already in active growth and will recover quickly from any hemlock pruning that needs to be done. In the fall and winter, hemlocks are preparing to go dormant and are hardening themselves to be able to withstand the cold of winter. Pruning hemlock trees in fall or winter can confuse the tree, causing it to return to active growth rather than dormancy. At best, the new growth it does produce will be killed off in the cold and, at worst, the entire tree will be unable to withstand the winter cold and the entire tree will die.
How to Prune Hemlock Trees
Trimming Hemlock to Correct Damage from Weather or Disease
High winds or heavy snows can sometimes damage the branches of a hemlock and you may need to prune the tree in order to remove some of the damage or to help reshape the hemlock. Disease may also kill back some of the branches on the tree and you will need to remove the diseased branches. The first step in pruning hemlocks is use a clean, sharp pair of pruning shears or pruning saw, depending on the size of the branches you need to prune. Clean and sharp pruning tools will help to prevent disease.
The next step in trimming hemlock branches is to select which branches need to be removed. Select the branches before you start trimming so that you do not over prune the tree accidentally. Then make your pruning cuts just above the needle whorls. Hemlock trees will grow new branches from the needle wholes and pruning just above them will ensure that the new branches come in properly. If damage to the hemlock tree is extensive, severe pruning may be needed. Hemlock trees can withstand severe pruning and will recover from losing as much as 50% of its branches.
Pruning Hemlocks to Remove Competing Main Trunks
Upright hemlock varieties look best when they have only one main trunks, so home owners often want to remove secondary upright trunks that may start to grow. These secondary trunks can be pruned back to their starting point on the main trunk or can be cut at any point along the trunk to stop its upward growth and encourage side growth instead.
When to Prune Hemlocks
If you find that you need to prune your hemlock tree, the best time for trimming hemlocks is in either spring or early summer. At this time, the tree is getting ready for or is already in active growth and will recover quickly from any hemlock pruning that needs to be done. In the fall and winter, hemlocks are preparing to go dormant and are hardening themselves to be able to withstand the cold of winter. Pruning hemlock trees in fall or winter can confuse the tree, causing it to return to active growth rather than dormancy. At best, the new growth it does produce will be killed off in the cold and, at worst, the entire tree will be unable to withstand the winter cold and the entire tree will die.
How to Prune Hemlock Trees
Trimming Hemlock to Correct Damage from Weather or Disease
High winds or heavy snows can sometimes damage the branches of a hemlock and you may need to prune the tree in order to remove some of the damage or to help reshape the hemlock. Disease may also kill back some of the branches on the tree and you will need to remove the diseased branches. The first step in pruning hemlocks is use a clean, sharp pair of pruning shears or pruning saw, depending on the size of the branches you need to prune. Clean and sharp pruning tools will help to prevent disease.
The next step in trimming hemlock branches is to select which branches need to be removed. Select the branches before you start trimming so that you do not over prune the tree accidentally. Then make your pruning cuts just above the needle whorls. Hemlock trees will grow new branches from the needle wholes and pruning just above them will ensure that the new branches come in properly. If damage to the hemlock tree is extensive, severe pruning may be needed. Hemlock trees can withstand severe pruning and will recover from losing as much as 50% of its branches.
Pruning Hemlocks to Remove Competing Main Trunks
Upright hemlock varieties look best when they have only one main trunks, so home owners often want to remove secondary upright trunks that may start to grow. These secondary trunks can be pruned back to their starting point on the main trunk or can be cut at any point along the trunk to stop its upward growth and encourage side growth instead.
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Dummer. ゛☀
2017年08月31日
Elm trees once lined city streets all across America, shading cars and sidewalks with their enormous, outstretched arms. By the 1930s, though, Dutch elm disease had arrived on our shores and began destroying these favorite trees of Main Streets everywhere. Although elms are still popular in home landscapes, American and European elms are highly susceptible to Dutch elm disease.
What is Dutch Elm Disease?
A fungal pathogen, Ophiostroma ulmi, is the cause of Dutch elm disease. This fungus is spread from tree to tree by boring beetles, making Dutch elm protection difficult at best. These tiny beetles burrow under the bark of elms and into the wood beneath, where they tunnel and lay their eggs. As they chew through the tree’s tissues, the fungal spores are rubbed off onto tunnel walls where they germinate, causing Dutch elm disease.
How to Detect Dutch Elm Disease
Signs of Dutch elm disease come on rapidly, over about a month’s time, typically in the spring when leaves are just maturing. One or more branches will be covered in yellow, wilted leaves that soon die and fall from the tree. As time goes on, the disease spreads to other branches, eventually consuming the whole tree.
Positive identification based on symptoms alone can be difficult because Dutch elm disease mimics water stress and other common disorders. However, if you cut open an affected branch or twig, it will contain a dark ring hidden in the tissues below the bark – this symptom is caused by fungal bodies clogging up the tree’s transport tissues.
Treatment for Dutch elm disease requires a community-wide effort to successfully eradicate both the beetles and fungal spores they carry. A single, isolated tree may be saved by pruning out affected branches and treating bark beetles, but multiple trees affected by Dutch elm disease may require removal in the end. Dutch elm disease is a frustrating and costly disease, but if you absolutely must have elms in your landscape, try the Asian elms – they have high levels of tolerance and resistance to the fungus.
What is Dutch Elm Disease?
A fungal pathogen, Ophiostroma ulmi, is the cause of Dutch elm disease. This fungus is spread from tree to tree by boring beetles, making Dutch elm protection difficult at best. These tiny beetles burrow under the bark of elms and into the wood beneath, where they tunnel and lay their eggs. As they chew through the tree’s tissues, the fungal spores are rubbed off onto tunnel walls where they germinate, causing Dutch elm disease.
How to Detect Dutch Elm Disease
Signs of Dutch elm disease come on rapidly, over about a month’s time, typically in the spring when leaves are just maturing. One or more branches will be covered in yellow, wilted leaves that soon die and fall from the tree. As time goes on, the disease spreads to other branches, eventually consuming the whole tree.
Positive identification based on symptoms alone can be difficult because Dutch elm disease mimics water stress and other common disorders. However, if you cut open an affected branch or twig, it will contain a dark ring hidden in the tissues below the bark – this symptom is caused by fungal bodies clogging up the tree’s transport tissues.
Treatment for Dutch elm disease requires a community-wide effort to successfully eradicate both the beetles and fungal spores they carry. A single, isolated tree may be saved by pruning out affected branches and treating bark beetles, but multiple trees affected by Dutch elm disease may require removal in the end. Dutch elm disease is a frustrating and costly disease, but if you absolutely must have elms in your landscape, try the Asian elms – they have high levels of tolerance and resistance to the fungus.
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Dummer. ゛☀
2017年08月31日
Stately elms once lined the streets of Midwestern and Eastern towns. In the 1930s, Dutch elm disease nearly wiped out these lovely trees, but they are making a strong comeback, thanks in part to the development of resistant varieties. Elm tree diseases still play a major role in the life of the trees and complicate their care. Anyone with an elm in their landscape should know the symptoms of disease so they can address problems promptly.
Diseases on Elm Trees
There are several elm tree leaf diseases that cause spotting, discoloration and defoliation. By the time the leaves fall from the tree, the spots have often grown together and other discolorations have developed, making it hard to differentiate between the diseases without a lab test.
Most elm tree diseases that attack the leaves are caused by fungi, but elm leaf scorch, caused by a bacterium, is a little different. With this disease, the bundles of veins in the leaves become clogged so that water can’t move within the leaf. This causes the leaf to look scorched. There is no known treatment for elm tree leaf scorch.
The most devastating elm tree diseases are Dutch elm disease and elm phloem necrosis. Dutch elm disease is caused by a fungus spread by elm bark beetles. The microscopic organism that causes elm phloem disease is spread by white-banded leafhoppers. The diseases look similar, with all of the leaves browning on affected branches, but you may be able to tell the difference by the location of the damage. Dutch elm disease usually starts on lower branches, and may appear random, affecting only part of the tree and leaving another part unscathed. Elm phloem necrosis affects the entire crown at once. Agricultural extension services in most areas ask that you report incidences of these diseases.
Treating Diseases of Elm Trees
Once elm tree leaf diseases take hold, there is no effective treatment. Rake and burn leaves to help prevent the spread of the diseases. If you have problems with leaf diseases, try using an anti-fungal spray early in the season the following year. This may help prevent disease. Powdery mildew is another leaf disease that sometimes effect elms, but it occurs so late in the season that treatment is unnecessary. There is no cure for Dutch elm or elm phloem disease. Trees infected with Dutch elm disease sometimes respond to pruning. This is a treatment that extends the life of the tree for several years if caught early and done properly, but it is not a cure. It’s best to hire a certified arborist for the job. Trees with elm phloem necrosis should be taken down as soon as possible.
Since there is no easy cure, it is important to learn how to protect elm trees from disease. Here are some tips:
Watch for the insects that cause elm tree diseases, and start a control program as soon as you see them. Rake and destroy elm tree leaves promptly. Use an antifungal spray if you had problems with elm leaves the previous year.
Diseases on Elm Trees
There are several elm tree leaf diseases that cause spotting, discoloration and defoliation. By the time the leaves fall from the tree, the spots have often grown together and other discolorations have developed, making it hard to differentiate between the diseases without a lab test.
Most elm tree diseases that attack the leaves are caused by fungi, but elm leaf scorch, caused by a bacterium, is a little different. With this disease, the bundles of veins in the leaves become clogged so that water can’t move within the leaf. This causes the leaf to look scorched. There is no known treatment for elm tree leaf scorch.
The most devastating elm tree diseases are Dutch elm disease and elm phloem necrosis. Dutch elm disease is caused by a fungus spread by elm bark beetles. The microscopic organism that causes elm phloem disease is spread by white-banded leafhoppers. The diseases look similar, with all of the leaves browning on affected branches, but you may be able to tell the difference by the location of the damage. Dutch elm disease usually starts on lower branches, and may appear random, affecting only part of the tree and leaving another part unscathed. Elm phloem necrosis affects the entire crown at once. Agricultural extension services in most areas ask that you report incidences of these diseases.
Treating Diseases of Elm Trees
Once elm tree leaf diseases take hold, there is no effective treatment. Rake and burn leaves to help prevent the spread of the diseases. If you have problems with leaf diseases, try using an anti-fungal spray early in the season the following year. This may help prevent disease. Powdery mildew is another leaf disease that sometimes effect elms, but it occurs so late in the season that treatment is unnecessary. There is no cure for Dutch elm or elm phloem disease. Trees infected with Dutch elm disease sometimes respond to pruning. This is a treatment that extends the life of the tree for several years if caught early and done properly, but it is not a cure. It’s best to hire a certified arborist for the job. Trees with elm phloem necrosis should be taken down as soon as possible.
Since there is no easy cure, it is important to learn how to protect elm trees from disease. Here are some tips:
Watch for the insects that cause elm tree diseases, and start a control program as soon as you see them. Rake and destroy elm tree leaves promptly. Use an antifungal spray if you had problems with elm leaves the previous year.
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Dummer. ゛☀
2017年08月31日
Elm yellows is a disease that attacks and kills native elms. Elm yellows disease in plants results from Candidatus Phyloplaasma ulmi, a bacteria without walls that is called a phyoplasma. The disease is systemic and lethal. Read on for information about the symptoms of elm yellow disease and whether there is any effective elm yellows treatment.
Elm Yellows Disease in Plants
The hosts of elm yellows phytoplasma in the United States are limited to elm trees (Ulmus spp.) and the insects that transport the bacteria. White-banded elm leafhoppers transport the disease, but other insects that feed on the inner elm bark – called phloem – may also play a similar role. Native elms in this country have not developed a resistance to the elm yellows phytoplasma. It threatens elm species in the eastern half of the United States, often killing trees within two years after the initial symptoms appear. Some species of elm in Europe and Asia are either tolerant or resistant.
Symptoms of Elm Yellow Disease
Elm yellows phytoplasma attack trees systematically. The entire crown develops symptoms, usually beginning with the oldest leaves. You can see symptoms of elm yellow disease in leaves during the summer, mid-July through September. Look for leaves that turn yellow, wilt and drop before they should. The leaf symptoms of elm yellow disease are not very different from problems caused by too little water or nutrient deficiencies. However, if you look at the inner bark, you will see elm phloem necrosis even before the leaves yellow.
What does elm phloem necrosis look like? The inner bark turns a darker color. It is usually almost white, but with elm phloem necrosis, it turns a deep honey color. Dark flecks may also appear in it. Another one of the typical symptoms of elm yellow disease is the smell. When moist inner bark is exposed (due to elm phloem necrosis), you will notice an odor of wintergreen oil.
Elm Yellows Treatment
Unfortunately, no effective elm yellows treatment has yet been developed. If you have an elm that is suffering from elm yellows disease in plants, remove the tree immediately to prevent the elm yellows phytoplasma from spreading to other elms in the area. If you are just planting elms, select disease resistant varieties from Europe. They may suffer from the disease but it will not kill them.
Elm Yellows Disease in Plants
The hosts of elm yellows phytoplasma in the United States are limited to elm trees (Ulmus spp.) and the insects that transport the bacteria. White-banded elm leafhoppers transport the disease, but other insects that feed on the inner elm bark – called phloem – may also play a similar role. Native elms in this country have not developed a resistance to the elm yellows phytoplasma. It threatens elm species in the eastern half of the United States, often killing trees within two years after the initial symptoms appear. Some species of elm in Europe and Asia are either tolerant or resistant.
Symptoms of Elm Yellow Disease
Elm yellows phytoplasma attack trees systematically. The entire crown develops symptoms, usually beginning with the oldest leaves. You can see symptoms of elm yellow disease in leaves during the summer, mid-July through September. Look for leaves that turn yellow, wilt and drop before they should. The leaf symptoms of elm yellow disease are not very different from problems caused by too little water or nutrient deficiencies. However, if you look at the inner bark, you will see elm phloem necrosis even before the leaves yellow.
What does elm phloem necrosis look like? The inner bark turns a darker color. It is usually almost white, but with elm phloem necrosis, it turns a deep honey color. Dark flecks may also appear in it. Another one of the typical symptoms of elm yellow disease is the smell. When moist inner bark is exposed (due to elm phloem necrosis), you will notice an odor of wintergreen oil.
Elm Yellows Treatment
Unfortunately, no effective elm yellows treatment has yet been developed. If you have an elm that is suffering from elm yellows disease in plants, remove the tree immediately to prevent the elm yellows phytoplasma from spreading to other elms in the area. If you are just planting elms, select disease resistant varieties from Europe. They may suffer from the disease but it will not kill them.
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Dummer. ゛☀
2017年08月31日
The American elm populations has been decimated by Dutch Elm disease, so gardeners in this country often choose to plant Japanese elm trees instead. This lovely group of trees is hardier and equally attractive, with smooth gray bark and an appealing canopy. Read on for Japanese elm tree facts, including information about how to grow a Japanese elm tree.
Japanese Elm Tree Facts
Japanese elm tree includes not one, but six genera with 35 species of elm native to Japan. All are deciduous trees or shrubs that are native to Japan and northeastern Asia.
Japanese elms are resistant to Dutch Elm disease, a disease fatal to the American elm. One type of Japanese elm, Ulmus davidiana var. japonica, is so highly resistant that is has been used to develop resistant cultivars. Japanese elm trees can mature to 55 feet tall with a 35-foot canopy spread. The bark is grayish brown and the crown of the tree rounded and spreads out in an umbrella shape. The fruits of Japanaese elm trees depend on the genera and variety of the tree. Some are samaras and some are nuts.
How to Grow a Japanese Elm Tree
If you want to start growing Japanese elm trees, you’ll have the easiest time if you plant the trees in an appropriate location. Japanese elm tree care requires a sunny planting site with well-draining, loamy soil. If you’re already growing Japanese elm trees in hard clay soil, you aren’t obliged to move them. The trees will survive, but they will grow much more slowly than in rich soil that drains well. The optimal soil will have a pH between 5.5 and 8.
Japanese Elm Tree Care
Also, when growing Japanese elm trees, you need to understand Japanese elm tree care requirements. When and how to water is perhaps the most important part of caring for these trees. Like other elms, Japanese elm trees need to be watered during extended dry periods. Provide water at the outside edge of their canopies, not close to the trunks. The root hairs of these trees that absorb water and nutrients are found on the root tips. Ideally, irrigate with a drip hose during periods of drought.
Japanese elm tree care also involves weeding around the trees. Weeds under an elm tree canopy compete for available water. Remove them regularly to keep your tree healthy.
Japanese Elm Tree Facts
Japanese elm tree includes not one, but six genera with 35 species of elm native to Japan. All are deciduous trees or shrubs that are native to Japan and northeastern Asia.
Japanese elms are resistant to Dutch Elm disease, a disease fatal to the American elm. One type of Japanese elm, Ulmus davidiana var. japonica, is so highly resistant that is has been used to develop resistant cultivars. Japanese elm trees can mature to 55 feet tall with a 35-foot canopy spread. The bark is grayish brown and the crown of the tree rounded and spreads out in an umbrella shape. The fruits of Japanaese elm trees depend on the genera and variety of the tree. Some are samaras and some are nuts.
How to Grow a Japanese Elm Tree
If you want to start growing Japanese elm trees, you’ll have the easiest time if you plant the trees in an appropriate location. Japanese elm tree care requires a sunny planting site with well-draining, loamy soil. If you’re already growing Japanese elm trees in hard clay soil, you aren’t obliged to move them. The trees will survive, but they will grow much more slowly than in rich soil that drains well. The optimal soil will have a pH between 5.5 and 8.
Japanese Elm Tree Care
Also, when growing Japanese elm trees, you need to understand Japanese elm tree care requirements. When and how to water is perhaps the most important part of caring for these trees. Like other elms, Japanese elm trees need to be watered during extended dry periods. Provide water at the outside edge of their canopies, not close to the trunks. The root hairs of these trees that absorb water and nutrients are found on the root tips. Ideally, irrigate with a drip hose during periods of drought.
Japanese elm tree care also involves weeding around the trees. Weeds under an elm tree canopy compete for available water. Remove them regularly to keep your tree healthy.
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Dummer. ゛☀
2017年08月30日
Flowering dogwood trees are a beautiful addition to any landscape. Unfortunately, this tree, like many others, is susceptible to attack from pests and disease that can cause damage and drastically shorten its life. Flowering dogwood problems such as disease and insects always hit weak or older trees first. The most common sign that your tree may be in trouble is when you notice the tree leaves dripping.
Why is My Dogwood Dripping Water?
Oftentimes, dogwood tree dripping, especially when watery in nature, is due to pests. Some of the most common pests that affect dogwoods and lead to tree leaves dripping include borers, scale, aphids and ants. Dogwood Borers – One very devastating problem with dogwood trees is dogwood borers, which are caterpillars that drill tunnels into the trunk of the tree. Weak and older trees are most susceptible to borers that leave wet areas on the bark early on. If you find your dogwood tree dripping sap, it may be a good indication that borers are at work. Once these damaging pests are inside a tree, they are very hard to eradicate.
Scale Insects – Scale insects are pesky little bugs that thrive on dogwood tree sap. They excrete a sugary liquid known as honeydew, which can down rain in large amounts and result in tree leaves dripping. Scale infestations are more damaging some years than others and seem to come in cycles. Using an insecticidal soap is an effective treatment for this problem. Tree Aphids – Aphids commonly affect ornamental trees and, like scale, will suck the sap from dogwoods. They also secrete honeydew, which can be recognized easily by a dogwood dripping water. Neem oil is a great way to control aphids on trees, or you can use a homemade solution of organic control as well.
Carpenter Ants and Rot – Some people may find their dogwood dripping water or the tree leaves dripping what appears to be water. It’s possible that carpenter ants and rot are causing this problem. These ants are so small that it is very hard to determine whether they are present or not. Carpenter ants feed on rotting wood. If there is a hole in the tree where water has accumulated, ants find plenty for dinner. Unfortunately, carpenter ants are very hard to get rid of once they are inside a tree. They dine on the inside of the tree, and the tree loses moisture through weeping. It is best to remove a tree that has carpenter ants before they move on to other trees in your landscape. Ants can also be found feasting on aphid honeydew, so check for these pests as well whenever you notice a dogwood tree dripping.
Dogwood Tree Sap
Not all flowering dogwood problems are the result of pests or disease. Dogwood tree dripping can also be the result of improper pruning. Sometimes dogwood trees are injured by other causes, such as a storm damage.
Since dogwood trees are known to be “bleeders,” they respond to injury by releasing sap, which will flow freely from the injured site. This dogwood tree sap is what is used to produce flowers and the tree must be left alone to heal. Always prune your dogwood trees in early summer to avoid injury and prune out any weak or older branches.
Why is My Dogwood Dripping Water?
Oftentimes, dogwood tree dripping, especially when watery in nature, is due to pests. Some of the most common pests that affect dogwoods and lead to tree leaves dripping include borers, scale, aphids and ants. Dogwood Borers – One very devastating problem with dogwood trees is dogwood borers, which are caterpillars that drill tunnels into the trunk of the tree. Weak and older trees are most susceptible to borers that leave wet areas on the bark early on. If you find your dogwood tree dripping sap, it may be a good indication that borers are at work. Once these damaging pests are inside a tree, they are very hard to eradicate.
Scale Insects – Scale insects are pesky little bugs that thrive on dogwood tree sap. They excrete a sugary liquid known as honeydew, which can down rain in large amounts and result in tree leaves dripping. Scale infestations are more damaging some years than others and seem to come in cycles. Using an insecticidal soap is an effective treatment for this problem. Tree Aphids – Aphids commonly affect ornamental trees and, like scale, will suck the sap from dogwoods. They also secrete honeydew, which can be recognized easily by a dogwood dripping water. Neem oil is a great way to control aphids on trees, or you can use a homemade solution of organic control as well.
Carpenter Ants and Rot – Some people may find their dogwood dripping water or the tree leaves dripping what appears to be water. It’s possible that carpenter ants and rot are causing this problem. These ants are so small that it is very hard to determine whether they are present or not. Carpenter ants feed on rotting wood. If there is a hole in the tree where water has accumulated, ants find plenty for dinner. Unfortunately, carpenter ants are very hard to get rid of once they are inside a tree. They dine on the inside of the tree, and the tree loses moisture through weeping. It is best to remove a tree that has carpenter ants before they move on to other trees in your landscape. Ants can also be found feasting on aphid honeydew, so check for these pests as well whenever you notice a dogwood tree dripping.
Dogwood Tree Sap
Not all flowering dogwood problems are the result of pests or disease. Dogwood tree dripping can also be the result of improper pruning. Sometimes dogwood trees are injured by other causes, such as a storm damage.
Since dogwood trees are known to be “bleeders,” they respond to injury by releasing sap, which will flow freely from the injured site. This dogwood tree sap is what is used to produce flowers and the tree must be left alone to heal. Always prune your dogwood trees in early summer to avoid injury and prune out any weak or older branches.
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Dummer. ゛☀
2017年08月30日
Dogwoods are native ornamental trees. Most flower and fruit, and have dazzling fall displays as the leaves change color. Peeling bark on dogwoods may be the result of serious disease or it could be a natural condition in some species. Knowing the species of your tree is crucial to deciding if a dogwood with peeling bark is in danger or if it is a normal occurrence. Dogwood is both a native and introduced species across North America, especially the cooler climates. The plants may be trees or shrubs in form, but all of them offer extraordinary color and many of them flower.
Many of the varieties are deciduous and provide a rich fall color display followed by bright green, yellow, coral and orange revealed stems. They are quite winter hardy but are sensitive to mechanical injury and a variety of pests and diseases. For this reason, the tree bark flaking on dogwood trees may be the result of a canker, borer, string trimmer or fungal disease, to name but a few.
When a Dogwood with Peeling Bark is Normal
The Kousa dogwood is an ornamental tree that is more cold tolerant than flowering dogwood. It has bark which peels off in irregular patches, revealing a mosaic of mottled colors underneath. The dogwood bark peeling off is part of this tree’s appeal, along with its winter interest and fall display of purple leaves. Other times that peeling bark on dogwoods may be normal is when it occurs due to wild herbivores rubbing their antlers or standing on the trunk. Small rodents may also chew on trunks and cause sloughing bark. None of these conditions are good for the tree but would be categorized as wildlife problems and completely normal in certain regions. Sunscald on young trees may also result in peeling bark. It is a good idea to site them where winter sun won’t be aggressive or paint the trunk with latex paint thinned with water. Drought conditions can cause cracked bark near the base. This condition is easily corrected by giving the plant supplemental moisture.
Dogwood Tree Bark is Peeling Due to Disease
Dogwood anthracnose is a common disease in the Cornus genus. It causes yellow leaves and twig dieback, as well as sunken discolored areas of tissue. These are common symptoms of branch and crown canker as well. Basal trunk canker will cause splitting and some loss of bark. It also presents with lesions in the tree that weep sap and can seriously affect the health of the tree. It is best to consult an arborist for either of these diseases which cause peeling bark on dogwoods.
Pests that Cause Tree Bark Flaking on Dogwood
Dogwood bark peeling off may be the result of tiny insects that do more harm than good. The dogwood twig borer is a nasty pest that gets into the vascular tissue of the tree and undermines the tissue. It lives in the tree’s tissue and causes bark upheaval in infested locations. These invasive creatures may be difficult to detect until widespread damage is done because they hide away from investigative eyes inside the plant. Other borers, like the apple tree borer, also appear to favor Cornus trees and cause similar damage.
Scale insects in high concentration may make it appear that the dogwood bark is peeling. This is because when they mass on a stem, they seem like hard-bodied scabs which can be easily flicked off with a fingernail. They have the appearance of damaged bark but are actually insects subject to pesticides and manual removal.
Many of the varieties are deciduous and provide a rich fall color display followed by bright green, yellow, coral and orange revealed stems. They are quite winter hardy but are sensitive to mechanical injury and a variety of pests and diseases. For this reason, the tree bark flaking on dogwood trees may be the result of a canker, borer, string trimmer or fungal disease, to name but a few.
When a Dogwood with Peeling Bark is Normal
The Kousa dogwood is an ornamental tree that is more cold tolerant than flowering dogwood. It has bark which peels off in irregular patches, revealing a mosaic of mottled colors underneath. The dogwood bark peeling off is part of this tree’s appeal, along with its winter interest and fall display of purple leaves. Other times that peeling bark on dogwoods may be normal is when it occurs due to wild herbivores rubbing their antlers or standing on the trunk. Small rodents may also chew on trunks and cause sloughing bark. None of these conditions are good for the tree but would be categorized as wildlife problems and completely normal in certain regions. Sunscald on young trees may also result in peeling bark. It is a good idea to site them where winter sun won’t be aggressive or paint the trunk with latex paint thinned with water. Drought conditions can cause cracked bark near the base. This condition is easily corrected by giving the plant supplemental moisture.
Dogwood Tree Bark is Peeling Due to Disease
Dogwood anthracnose is a common disease in the Cornus genus. It causes yellow leaves and twig dieback, as well as sunken discolored areas of tissue. These are common symptoms of branch and crown canker as well. Basal trunk canker will cause splitting and some loss of bark. It also presents with lesions in the tree that weep sap and can seriously affect the health of the tree. It is best to consult an arborist for either of these diseases which cause peeling bark on dogwoods.
Pests that Cause Tree Bark Flaking on Dogwood
Dogwood bark peeling off may be the result of tiny insects that do more harm than good. The dogwood twig borer is a nasty pest that gets into the vascular tissue of the tree and undermines the tissue. It lives in the tree’s tissue and causes bark upheaval in infested locations. These invasive creatures may be difficult to detect until widespread damage is done because they hide away from investigative eyes inside the plant. Other borers, like the apple tree borer, also appear to favor Cornus trees and cause similar damage.
Scale insects in high concentration may make it appear that the dogwood bark is peeling. This is because when they mass on a stem, they seem like hard-bodied scabs which can be easily flicked off with a fingernail. They have the appearance of damaged bark but are actually insects subject to pesticides and manual removal.
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