Question
We live in Massachusetts, and 37 years ago we planted our blue spruce Christmas tree way to close to the house, not realizing how big it would get.  It has to be 20 feet wide at the base, and we are looking to prune it back as it is in the roof line now.  Can we trim the branches from the bottom and mulch there.  The tree is huge, please help

Answer
I think the question is --the limbs are rubbing the house and you want to prune the lower limbs off above the house so they will not hit the house?? If this is the question--You can prune the lower limbs but the blue spruce will not look like the normal spruce with the limbs going to the ground. It will have the appearance of a pine with a trunk then the branches start.

Current pruning recommendations advise against pruning branches flush to the trunk. Flush cutting is harmful in several ways: it damages bark as pruning tools rub against the trunk, it removes the branch collar, and it goes behind the branch bark ridge. The branch collar is the swollen area of trunk tissue that forms around the base of a branch. The branch bark ridge is a line of rough bark running from the branch-trunk crotch into the trunk bark, less prominent on some trees than on others.

The best pruning cut is made outside the branch collar, at a 45 to 60 degree angle to the branch bark ridge. Leave the branch collar intact to help prevent decay from entering the trunk.

Whenever removing limbs greater than one inch in diameter, use the three-cut method to avoid tearing bark. First, about 12 inches from the trunk, cut halfway through the limb from the underside. Second, about 1 inch past the first cut, cut through the limb from the top side. The limb's weight will cause it to break between the two cuts. Make the third cut outside the branch collar. Don't coat pruning cuts with tree paint or wound dressing, except for control of certain disease-carrying insects. These materials won't prevent decay or promote wound closure.

Here is a web link to pictures of the procedure for large branch pruning. http://www.tree-pruning.com/how-to-prune.html