Birch tree dies from top-down if there’s a severe infestation of Bronze Birch Borer. Leafminers also damage the Birch tree to a certain extent. Heat stress turns the foliage yellow in Birch trees.
Birch tree dying from top down
Birch tree dies from the top down when the tree is heavily infested by the bronze birch borers. The foliage dies from the top towards the bottom when it’s infested by these pesky pests.
Bronze Birch Borer is a type of beetle that lays eggs in the trunk of the tree in the summer season. These eggs turn into larvae in several weeks.
Bronze Birch Borer Identification
Adult Bronze Birch borer may look olive to brown in color with coppery wings. The larvae are pale white in color and are elongated.
These larvae are present under the bark of the birch tree.
Bronze Birch Borer Damage
Bronze Birch Borer larvae eat away the plant for two years before you can actually see the symptoms. The points of exits of the larvae are D-shaped.
Once the symptoms are visible, there’s no way to bring the tree back to life. Bronze Birch Borers eat away the insides of the tree, blocking the food and water supply.
These pests create a maze inside the tree trunk by eating it away.
Bronze Birch Borer Signs
Defoliation and yellowing of the foliage are the primary symptoms of a Bronze Birch Borer infestation. The top branches of the Birch tree turn brown.
This dieback starts from the top and slowly proceeds to the bottom of the tree. Infested branches turn brown and ridges can be seen.
You need to respond at this stage of the infestation. If you leave it as is, the following symptoms develop.
Bronze Birch Borer Symptoms
If you haven’t responded quickly to the early signs, the following symptoms develop at a later stage of the infestation.
- D-shaped exit points of the larvae can be seen on the trunk of the tree.
- Bark powder can be seen in such D-shaped grooves of the trunk.
Bronze Birch Borer Treatment
You can treat a Bronze Birch borer infested plant using TREE-äge or IMA-jet. They both have the capability to move through the vascular system of the Birch tree.
Treat the tree early on, before a lot of damage occurs to the Birch tree. Apply these insecticides in the spring for the best results.
You can apply them in the growing season to prevent the growth of adults.
Note: Such applications are not made more than once a year.
Bayer Birch Borer Treatment
One can apply Bayer Tree and Shrub Protect I or Bayer Tree and Shrub Protect II to the soil. Take professional help to apply these to the tree.
Professionals may apply to the soil or the trunk directly, depending upon the situation.
Bronze Birch Borer Management
Treat the Susceptible/affected tree in the spring with a suitable insecticide. Treat the tree once more in the summer for the best results.
Such treatments would prevent a full-blown infestation of the Birch tree. Summer treatment should be done in the morning when the temperature is cooler.
What eats Birch tree leaves?
Leafminers are a huge problem that the Birch trees face. Leafminers eat the Birch tree leaves. They are the common pests of the Birch tree.
Leafminers, as the name, suggests eat away the leaves of the Birch tree. They leave trails as they eat away the leaf tissues.
Birch leafminers are sawflies, whose larvae munch on the Birch leaves.
Birch Leafminer damage
The parts of the leaves that are eaten by Leafminers turn brown. If you haven’t noticed the early symptoms, it may look like the Birch tree got scorched.
Leafminers do not affect more than 40% of the leaves usually. Even if they affect 60% of the leaves, healthy Birch can handle it.
When to treat the Birch for Leafminers?
It is best to treat the susceptible Birch tree before you see any symptoms. To do this, you need to keep track of the tree’s growth.
Leafminers usually appear 10 days after the bud break. Monitor your Birch tree closely and treat the tree just before the bud break.
How do you treat Birch Leafminer?
Treat the susceptible Birch tree by spraying a systemic pesticide like acephate or dimethoate on the leaves. It gets absorbed into the leaves and kills the larvae.
You can paint some undiluted Cygon 2E on the susceptible tree at bud break. This method works best on smaller trees.
Why do Birch tree leaves turn yellow?
Birch leaves turn yellow due to heat stress. Improper watering also causes leaf yellowing in Birch trees.
You might observe this in the summer season, this is a natural reaction by the tree to the scorching heat. Leaves become yellow and fall off.
Birch tree leaves turning brown in summer
Such yellowing leaves eventually turn brown. This is the natural progression of a heat-stressed plant. You need not panic, such plants can be revived.
If the tree is young, move the plant to a shadier place. If the tree is established, provide some shade to the tree using artificial means or by planting another tree.
Why are the leaves falling off my Birch tree?
Leaves fall off the Birch tree when it’s experiencing heat stress. Leaves fall off in River Birches when the climate is hot and dry.
Leaves near the center of the tree turn yellow and drop off. Observe the plant closely to see if this is what’s happening.
Well-established/Healthy plants aren’t much affected by Hot, Dry climates. They can withstand heat stress.
Sick plants or plants that haven’t established, i.e., planted in the last 3 to 5 years might not withstand heat stress.
Water your young trees adequately to help them survive the heat stress. Water the trees once a week in the hot season to keep them hydrated.
Happy Growing 🙂
References
https://naturalresources.extension.iastate.edu/forestry/iowa_trees/trees/river_birch.html