Question
We need to have our silver maple trimmed back as one large, long limb is growing directly over our neighbor's roof and she is afraid it might fall on her house in a storm. We had a trimmer come and he said he would trim the limb right back to the main trunk of the tree and cut it flush and smooth, with no collar. However, I have read in tree trimming tips that is a mistake and can damage the tree. They say to leave a short collar of a few inches that makes it easier for the tree to heal. Which way is correct and will help the tree heal faster? Should we paint the open wound with sealant to protect it or wait for it to heal on it's own?

Answer
It needs to have a branch collar left not a stub. These are only about a 1/4 inch from the trunk. This will allow the branch wound to heal much faster. I wound do not apply any wound dressing on the wound this tends to slow down the healing process.


Here is a web link showing the branch collar and pruning techniques. If a large limb is to be removed, its weight should first be reduced. This is done by making an undercut about 12 to 18 inches from the limb抯 point of attachment. Make a second cut from the top, directly above or a few inches farther out on the limb. Doing so removes the limb, leaving the 12- to 18-inch stub. Remove the stub by cutting back to the branch collar. This technique reduces the possibility of tearing the bark


http://www.na.fs.fed.us/spfo/pubs/howtos/ht_prune/cuts.htm