Question
I have a large silver maple in my front yard (approx 20-25 years old) and maybe 40-45 feet tall.  About 18 months ago in the Summer I was redoing my lawn and an overzealous dirt removal crew removed a large portion of this tree's roots.  The roots were cut back to about 10-12 feet from the trunk all the way around the tree.  These were not nice clean cuts either, many of the roots were torn and mangled when I investigated.  In short, the tree was traumatized.  Needless to say the tree went into shock, but made it through that initial Summer and Fall.  The roots were covered quickly with new dirt and plent of water was provided as I tried to minimize the damage.  When it came back in the Spring the leaves were smaller and thinner than usual.  The tree made it through the whole growing Season in this sort of lame (stunted) fashion.  I'm wondering what to expect for the next Season.  Is the tree likely to continue showing a stunted development or should I expect it to eventually return to full sized leaves and vigorous growth?  Any comments or shared experiences would be appreciated.  mdk

Answer
I would expect it to still show signs of stress. I would recommend fertilizing the tree. Apply 3 to 5 lb of 10-6-4 (or similar analysis fertilizer) for each inch of trunk diameter measured at 4 1/2 ft above ground. For example, a 10-inch diameter tree required 30 to 50 lb of 10-6-4 fertilizer. Diameters can be found by the following formula:

Diameter = circumference x .318

The simplest and fastest way to apply fertilizer is to spread it on the lawn or soil surface under the branch spread. (Many horticulturists believe this method to be just as effective.) To prevent lawn or groundcover damage, the fertilizer should be applied in split applications with thorough watering after each application. One application of the recommended amount followed by thorough watering is sufficient on bare soil areas.