We have 2 birch trees. One a paper birch and another a river birch and they...

Asked April 15, 2014, 8:33 PM EDT

We have 2 birch trees. One a paper birch and another a river birch and they both have large icicles coming from the trees. We have never seen that before. What is making that happen?

Kandiyohi County Minnesota

1 Response

In late winter, as the temperature becomes warmer, birch and maple trees begin to awaken from their winter dormancy. They draw water from the ground, pulling it up toward the branches. As water travels through the wood, it picks up stored sugar and other nutrients, carrying them to the buds. In late winter, pressure in birch trees causes sap to flow freely out of spring pruning or wounding holes in the wood, or even to drip from a broken branch. Though this “bleeding” cause little harm, it may still be a source of concern. To prevent bleeding, we usually recommend that you prune the birch trees after their leaves are fully expanded in late spring or early summer. Most trees are best pruned in late winter while they are still dormant. Your tree has a wound and the dripping sap froze due to our unusually cold April temperatures.