Question
We just transplanted a water oak.  I'm not sure my husband got enough of the root.  Do you think it will die because of that?  And, if not, how often should I fertilize it?  We live in SC.

Answer
Tina,

My experience with oaks hasn't been that good.  For as big and tough as they are, they can be touchy when transplanted.  So, if I had cut too small of a root ball on an oak, I wouldn't expect it to live.

Fertilizing might help.  Go ahead and put on some winter fertilizer now.  If it's a large tree, you could poke some holes around the drip line and wash some fertilizer down the holes.  

Winter fertilizer will help  root system strengthen up for over the winter.
Fertilizer is marked with 3 numbers (10-10-5, for example) to identify what it's made of. (N-P-K).   As a general rule Winter fertilizer has a high last number (like 8-5-15, for example).  The exact numbers don't matter so much, just look for high last number

Don't fertilize more than once per season.

If you've staked it, make sure that it's not tied too tight.  The tree should still be able to move some in the wind.  Movement stimulates root growth.

Make sure it's not planted too deep.  The top of the original root ball should be even with the top of the soil in the new location.

As soon as it's transplanted, it should be watered in VERY well.  This is to make sure that the root/soil connection is a good one.

Hope this helps.
Mark in Portland