There is no treatment for Dutch elm disease or elm phloem disease. Pruning can help trees affected with Dutch elm disease. This is a therapy that, if discovered early and done correctly, can extend the life of the tree for several years, but it is not a cure. There are various species of elms found in North America, most notably the American elm (Ulmus americana).
Elms are deciduous trees that grow in moist soil in full sun or partial shade. They are widely used as street trees because of their fast growth rate and long lifespan. Elms bear flowers in spring before leaves appear on the tree, then fruit called samaras after the flowering season has passed. The outer skin of the samara contains two large bristly hooks that give it a fuzzy appearance. It can be red, orange, or yellow when ripe.
Dutch elm disease was first identified in New York State in 1955, but it is now known to have been present in the state since at least 1918. It is caused by a fungus named Ceratocystis fimbriata which grows inside elm bark and kills the inner wood, resulting in death of the tree. Infected trees usually die within eight to ten years of infection but some live longer than this due to genetic factors within the tree itself. As far as we know, there is no way to genetically modify elms so far as to make them immune to the disease.
To properly eliminate both the beetles and the fungal spores that they transport, treatment for Dutch elm disease necessitates a community-wide effort. A single, isolated tree may be salvaged by cutting away diseased branches and treating bark beetles, but several trees infected with Dutch elm disease may eventually necessitate removal. Where elms are used as street trees or for other public purposes, such removal is undesirable if possible.
Trees with Dutch elm disease can be divided into two groups: those that remain standing after infection and those that do not. Infected trees that continue to produce healthy leaves and seeds are called carriers. Carriers usually die within 10 years of being infected but sometimes live much longer. They can still spread the fungus through their roots or through their pollen. Carrying trees should be removed because they can infect other elms with which they come in contact. The only cure for Dutch elm disease is removal of the carrier tree. If another elm gets sick from contact with its roots, it too will have to be removed at some point.
Trees with Dutch elm disease can also be divided into two groups: those that remain standing after infection and those that fall over after infection. In this case, the term "disease" does not mean that the tree is bad or unhealthy but rather that it has been affected by elm phloem necrosis, or ELP for short.
Dutch elm disease may spread from diseased trees to healthy elms via root transplants. To avoid this movement, cut root grafts using a vibratory plow before removing the sick tree. Choose disease-resistant varieties of Dutch elm for new plantings or replacement trees. If you cannot find resistant varieties, protect young trees by growing them in a protected environment until they are older and more mature.
Disease can also be spread by wind-blown pollen, which can land on other elms and infect their roots. Pollen from diseased trees may be able to travel greater distances than seed because there are no restrictions on how far it can travel through the air. Avoid planting different species of trees within 50 miles of each other to prevent cross-pollination. Species at risk of being affected by Dutch elm disease include American elm, Chinese elm, and Siberian elm.
In addition to these methods, Dutch elm disease is known to be spread by insects. The primary vector for transmission of the fungus that causes the disease is the insect known as the elm bark beetle. Other species of bark beetles, as well as wood wasps, stingless bees, and carpenter ants, also attack elms and can transport the fungus between trees.
Once infected, a tree will usually die within eight years.
Dutch elm disease is presently only actively controlled in a few areas of the United Kingdom, and there is no requirement to notify infected trees. However, if you want to be reminded of how beautiful mature elms can be, you may do so by visiting the elms in and around Brighton and Hove. These are mostly descendants of 17th- and 18th-century elms that have been saved from the tree surgeon's axel.
In addition, there are a number of small isolated colonies of disease-free elms in parks and public spaces across southern England. One such colony is located in Dedham within the boundaries of Sutton District Council. There are also several smaller colonies in Surrey including one in Hillingdon near where the River Baker flows into the Thames near Richmond.
These elms were all planted between 1890 and 1920 as part of a scheme to re-vegetate open spaces after the devastation of the Victorian era. They represent the best hope for the future survival of this important species in Europe.
In fact, British elms have been used in continental Europe as a source of wood since at least 1629 when an elm tree was brought from London to Brussels. Although most of these trees died, a few survived to grow up alongside new trees sent from home.
The greatest approach to keep Dutch Elm Disease at bay is to keep your elm happy and healthy. You may accomplish this by watering your trees during dry spells. Pruning and deadwooding every few years (no more than every 8 years) will assist. If any branches are broken, they should be removed from the tree to prevent the spread of infection.
Dutch elm disease is a bacterial disease that can kill mature elms. The bacteria enters through small wounds in the bark or leaves of the elm tree and grows inside the wood. It eventually causes the tree to die. The only way to stop the disease spreading is to remove infected trees. This might not be an option if you value the timber produced by your elms. However, if all other options have been tried and failed, then removing infected trees may be necessary to save the rest of your elms.
If you are planting new elms, try to buy disease-free seedlings. This will help prevent spreading the disease to healthy trees.
As well as removing infected trees, there are measures you can take to protect healthy elms from being infected. These include: avoid pruning elms during wet seasons; don't use chemical sprays on your plants; and don't move infected materials.