I have flowering locust tree i would like help with how to prune it it had a y and one half broke off about 2 years ago how do i fix what is left thank you
This tree is too close to the building in the picture, which may be why no one has answered. Best to relocate it next Winter. Remove all the growth on the right including the stub, but do not cut completely flush to the trunk leave a small protrusion (1/4 inch or so). Make certain the cuts angle to the right, NOT like the flat cut in the picture. Any remaining roots in the original location will likely sprout so be prepared to treat them with a Brush Killer/Poison Ivy Killer in the Spring.
The best time to perform major pruning is when the tree is dormant in the winter. You can do some lighter pruning once the bloom is done. As a rule of thumb, you cannot remove more than 25 percent of a trees foliage at one time. It's best if you remove no more than 15 percent, but hey, that can't always happen. Start reducing the branches on the right hand side where the co-dominant stem previously broke off. If you remove approximately half of that growth, new growth will be produced on the older co-dominant stem. I can't really tell in the picture how much included bark is present. It looks like it almost goes all the way to the outside of the trunk. Maybe post another picture of where the co-dominant stems met (the y)
Another possibility is to remove the suckers manually. After all there is nothing wrong with a little bit of physical exercise.
"another possibility is to remove the suckers manually. " To each his own. I'd rather not dig up suckers in 100F and spend two or three years at it. Robinia is known for it's extreme suckering and tenacity. http://www.burkesbackyard.com.au/factsheets/Trees-and-Palms/Suckering-Robinia/1743 Suckering up to 56 feet away!
