You usually don't think about mistletoe until it's used as a holiday decoration. This strange plant has a long history of romance, fertility, magic, and even diplomatic purposes. But for trees, this plant is a thief, defacing and possibly killing them. How to remove mistletoe and prevent mistletoe infestation, read on!
What is mistletoe and how does it spread?
Mistletoe is usually only noticed when the deciduous trees lose their leaves for the winter. At this time the plant stands out as it is the greenest part of the tree canopy. It is hemiparasitic because it is not completely dependent on the tree for its entire subsistence like a true parasite.
Mistletoe is a plant and, like any other plant, is spread by seeds. The fruit is a white berry that is very sticky when broken. This stickiness allows the seed to easily stick to birds, squirrels and trees.
What damage does the hemiparasitic plant cause?
Mistletoe grows best on stressed and weakened trees. Our built environment (cities, suburbs, etc.) stresses trees and makes them vulnerable to mistletoe infestation. Common stresses faced by trees include soil compaction, shallow soil, rocky soil, poor drainage, low fertility, and even root loss due to digging.
The initial growth of mistletoe in a new infestation is slow andharms the treebarely. Later - usually after years - the mistletoe reaches a size that demands so much from the tree that branches beyond the infestation begin to die off due to lack of water. Often the tree reacts to the plant as if it were a disease or an insect. The tree closes the damaged portion to contain the problem, resulting in more dead branches.
Whole trees rarely die from mistletoe, but rather from many problems together, mistletoe being just one of them. The more the plant infests the tree, the more stressed it becomes, allowing further problems to develop. Common secondary problems associated with mistletoe include diseases and pests that take advantage of the stressed tree. Hypoxylon canker and ragweed beetle are good examples of this.
How do you remove mistletoe from trees?
The sooner you remove the mistletoe from fruit trees, the greater the chances that the tree will not become disfigured or even die. The decision to combat mistletoe depends on its quantity in the tree, the duration of the infestation and the stress the tree is showing.
Improving tree health
How can you prevent mistletoe infestation? The healthier your tree is, the better it can defend itself against mistletoe infestation or fight existing mistletoe. Good tree care always begins with creating the most stress-free conditions possible for tree growth - good, uncompacted soil with an appropriate content of minerals, organic matter and water.
Mulching trees helps achieve many of these desirable conditions at minimal cost and at the same timethe health of the treeto promote. Apply the mulch in a 5 cm thick layer over as large an area as possible. Begin by completely mulching the area below the tree's drip line. Do not pile the mulch against the trunk as this will encourage other problems.
Pruning mistletoe
Cut the mistletoe back to the branch collar or a side branch to allow the tree to recover. If the plant has already established itself in a tree, the most common control measure is to cut out the plant. For small trees or infestations close to the ground, anyone can remove the mistletoe by simply cutting it off the tree. Since the haustoria are still in the tree, there is a high probability that the mistletoe will grow back again. Complete control is only possible by removing the entire plant, both inside and outside the tree.
How to remove mistletoe, but completely?Cut branches back at least 6 inches below where the plant is growing. When removing branches, cut back to the collar or a secondary branch to allow the tree to recover from removal.
It is also important not to over-prune your tree. The most common recommendation is to remove no more than 20 to 30 percent of the canopy of a young, healthy tree in a year. For older orunhealthy treesYou should not remove more than 10% of the tree canopy in one year. Mistletoe removal may need to be spread out over several years to ensure your tree recovers well.
Removing entire trees
Occasionally a tree may be so badly infested with mistletoe that complete removal is the best solution. There is no clear guideline as to whether you should control mistletoe or remove the tree. The following criteria can help you decide:
How heavily is the tree overgrown with mistletoe?
A tree whose branches are 30 to 50 percent covered with mistletoe needs to be cut back heavily, even over several years. Without large parts of the tree's canopy, the tree can no longer produce as much energy, leading to slow wound closure, which in turn leads to rot inside the tree and is an open invitation for disease and pests.
How healthy and strong is the tree?
An older tree or a tree in poor health may only tolerate minor pruning. A severe infestation can best be combated over many years.If the treeis in poor health, he may already be suffering from other problems that would be made worse by mistletoe control. For unhealthy and older trees with heavy infestations (more than 30 percent of branches), removal is the better option unless the cost of multi-year inspections and treatments to maintain tree health can be justified.
