It is never advisable to fertilize a sick tree, unless it is showing signs
of nutrient deficiency. If the trees are ailing because their root zones
have been compacted or partially destroyed via passing heavy equipment,
there is very little you can do to save them. Red oaks are somewhat tolerant
of this as are bleck birch, so the builder must have really done a number on
their root zones.

Dave

"GaryM" wrote in message
. 3.44...
I have now two trees on my new lot exhibiting signs of sickness. A red
oak and a black birch. In reality it was due to the builders and the
way they "rearranged things". I was told by tree expert that instead of
spending a lot of money on expensive treatments I should try lawn
fertilizer on the drip line. Is this worth a shot or should I just let
the tree try to restablish itself? Does anyone have specifics on the
process. At this stage I know to use holes 18" deep on the drip line in
a concentric circle. But how much fertilzer? I have a 10:10:10 mix I
was going to try.

Thanks in advance.