View Full Version : White Pine and Paper Birch

10-15-2004, 06:18 PM

I recall reading in the Arbor Day Library of Trees on White Pines earlier this year that White Pine roots can be toxic to some plants and trees. I have a Paper Birch that suddenly died this summer over about a six week period. I noticed that the drip line of an adjacent White Pine was just about getting to the tree so the roots were growing into the Birch's domain. The top third of the tree suddenly died off late last winter starting at the branch tips and progressing inward and downward toward the trunk. The remainder of the tree grew fine over the spring and early summer but the tree suddenly died over a six week period in July and August again starting at the trees extremities and progressing toward the trunk. We had a cool and wet summer so I don't think weather was the issue. My best guess is that the White Pine or desease killed it. Are White Pines toxic to Paper Birchs?

The Paper Birch in the forground of a clump of White Pines is very attractive during the winter IMO. Can I replace the birch with a new one or will it suffer the same fate? I wanted to add a picture of the tree shortly after it died to this post but I don't have access to a public domain to host the image. Sorry. :cry:

10-15-2004, 08:33 PM
The most common killer of birches is the bronze birch borer (Agrilus anxius) - a Buprestid beetle that specializes in feeding under the bark of birches. It doesn't attack healthy trees, but most white, paper, or yellow birches in urban landscapes are stressed enough by their environment to be succeptible. Look for small, D-shaped holes in the trunk.

It is possible that the white pine contributed to the stress on the birch, either through root competition, compounds from the roots and fallen needles, or (very possibly) through shade. Was the paper birch positioned for full sun throughout the day? Even partial shade would be enough to stress one out. My money would be on the borer for the actual killing blow, but there may have been other factors like that which initially weakened the tree.

At one place I lived, every yard had a European white birch tree (we lived on Birchwood Dr.). Every few years, they would fall to BBB, get cut down, and resprout from the stumps to start the cycle over again.

10-18-2004, 12:14 PM
I'm pretty sure it wasn't the white pine that you read about. Black walnut trees have juglone in their roots and leaves and this natural herbicide can kill many intolerant trees, shrubs, weeds, and even vegetables. Take care not to use black walnut parts as compost or mulch.