Q It seems like birch trees grow well around here, but I had bad luck with mine. Its branches died from the top down, and I had to have it removed. I really love birch trees, but I wonder if it's worth it to try planting one again.
A Yes, try again. Chances are good that a new birch will live long enough to justify your efforts. But there are some things you should know about birch trees.
These shallow-rooted trees need a fair amount of moisture. The best way to keep them healthy is to make sure they have adequate soil moisture throughout the growing season. When you plant your new birch, remove a good-sized circle of sod around it and replace the sod with several inches of mulch, such as shredded bark or wood chips. The mulch will help conserve moisture and keep the roots cooler, and the developing tree will not have to compete with the established turf grass for moisture or nutrients.
Even as the tree grows, don't leave it to the mercy of natural rainfall. Continue to water it as you would a young tree, particularly during dry weather. And add to the mulch layer as it decomposes, to maintain a depth of 3 to 4 inches.
There is one downfall to planting birch trees. When under stress (from being planted in dry, sandy soil or prolonged hot, dry weather without adequate moisture), they're vulnerable to a potentially fatal pest, the bronze birch borer. River birches are less susceptible to the borers than are paper birch trees. And though river birches lack the classic white bark, their curly, cinnamon-colored bark has its own charm.
Deb Brown is a garden writer and former extension horticulturist with the University of Minnesota. To ask her a gardening question, call 612-673-7793 and leave a message. She will answer questions in this column only.