I recently got the following question from a reader of my syndicated column, "A Greener View":
"We transplanted some 3.5-inch caliper trees six years ago. They seem to be generally healthy, but the leaves have never been full or bright or strong. The fruit trees and spruce trees we have seem fine, but the trees with this problem are red oaks, sunset maples, crimson king Norway maples and white birches. I had them professionally fertilized twice during their second and third years, and I gave them all some fertilizer spikes this year. They did seem a little better this year, but they still kind of look droopy."
Here's my answer: All of the trees you list as being wilted are ones that need a bit more moisture than many other landscape trees. They all are naturally found in lowlands or wetlands that have more water in the soil.
Are the trees planted lower or higher than the surrounding areas? How good is the soil surrounding the transplanted root balls? The trees may grow well for a year or two, but if they can't get their roots out into a much larger area, they will not do well long term.
To see how well the trees have done since they were planted, check the branches. The leaves on deciduous trees only grow on the current year's new branch. This year's new growth will not have any side branches, and it will be a different color than last year's growth. Last year's growth will also have a slightly different texture and side branches. You should be able to tell the difference between each year's growth for several years back.
Look to see whether the branches have been getting longer and stronger. On a long branch, you can count all the way back to the year the tree was dug up for transplant, and you will see that the growth that year is much shorter than that of recent years. If the new growth is staying short, then the trees are not recovering from the transplant.
The recovery time for the transplant should only be about a year for each inch of trunk diameter. Your trees should have been fully recovered a couple of years ago, and the length of new growth this year should have been at least a foot long.
If the trees have been watered and fertilized, the problem is probably in the soil, but I think you should have a licensed arborist come out and look at your trees to give you a diagnosis.
Jeff Rugg's weekly column, "A Greener View," can be found at creators.com.