Question
We have three Columnar Swedish Aspen trees in the same general location.  This year (year 3) one of the trees came back very slowly and only had growth from six feet on up.  Compared to the other two thriving trees the growth is sparse.  We were told to cut the top off to promote new growth.  Is this a viable option and how much should we cut off?  We were told there may have been a spring freeze that damaged the leave buds.  Will these come back next year?  We are in the Boulder, CO area.

Answer
Know do not cut the top off the tree.  If there are dead branches then these can be pruned off but cutting the top will stunt the growth not increase it. I would fertilize the tree with 10-10-10 fertilizer at the rate of 1 lb per inch of trunk diameter scattered around the tree and water in good. This will promote root growth and leave growth.