DEAR JESSICA: I've had a gray birch for two years. I have been pulling off mushroom-type growths for a while, but haven't seen any recently. Now I'm noticing that the bark on one section appears peeled. Can I use a pruner-sealer product to close it?-- Camille Simonetti, Flushing
DEAR CAMILLE: Bark serves as the "skin" of the tree, protecting it from the elements, insects and disease. So when a substantial amount of bark is missing or damaged, or the tree has a deep wound, its health can be severely compromised, as the injury can interfere with the transportation of water and nutrients throughout the plant.
When we are injured, we cover our wounds with bandages to protect them while they heal, so it seems reasonable that we'd want to protect a tree's wound in a similar fashion. But that's not necessarily what's best for the tree.
One problem with the application of tar or wound sealer is the risk of sealing in insects or moisture that can lead to decay and further damage. Another is that, just as you would change your bandage regularly while your own cut or scrape heals, you would have to be vigilant about reapplying the sealer, which, let's face it, isn't likely.
From your description, it doesn't seem like your tree's wound is particularly deep or large. If that's case, then I advise cleaning up around the area by cutting away any loose, damaged or decaying bark with a sharp knife. Water regularly, ensuring the tree gets an inch or so of water weekly throughout its recovery period. Given time, the tree will heal on its own.
If, however, the damage is more extensive and a large area of bark (more than 25 percent around the trunk) is torn off at the site of damage, then the tree could be in danger. In this case, use your sharp knife to cut around the injury as above, removing all the damaged portions of bark, taking care not to cut deeply into the tree's vascular tissue. Then wait and see what happens. If the tree is otherwise healthy and the damage isn't too extensive, it may very well recover. If not, there really isn't anything else you can do.
DEAR JESSICA: Could you tell me when and how much I can trim these bushes/trees, and when and if they can be transplanted? I think they are three years old. -- Bob Nielsen, Baldwin
DEAR BOB: Those are trees, not bushes, and they're planted way too close together. I recommend you move them elsewhere and plant proper shrubs in that spot. You might consider Deutzia, inkberry or Knockout roses.
The best times to transplant trees are early spring and late fall. When you do so, dig up as much of the root ball as possible, taking care not to damage or injure roots. Prepare a hole where the tree is to be moved that is twice as wide (but exactly as deep) as the roots. Soak the empty hole with water, and add some compost, but no fertilizer. Then set the roots in and backfill with soil, tamping down firmly as you go. Be sure the trees get 1 to 11/2 inches of water weekly, from a combination of rainfall and supplemental irrigation, for the first year, even during winter dry spells. After that, you can reduce watering to only during dry spells.