Question
Hi- I have two older Magnolia trees in my front yard, and understand that they have shallow root systems.  The trees are about 30 feet high.  In putting in a patio on one side, the contractors cut the roots away on all four sides three feet from the trunk.  I discovered this today, and am really concerned that the tree will not survive.  What can I do to help the tree?

Answer
You can get a way with cutting 25-30% of a tree root system without causing serious damage more than this will cause foliage die back and could even cause the tree to die. The root are within the first 2 feet of soil so if they were cut all the way around the tree you will get major dieback. I would water the tree with 1 inch of water --place a pan under the tree and turn the sprinkler on and when the pan has 1 inch of water in it stop. Do this every third day for a month then once a week if it does not rain. I would do this thought out  the winter if the temperature is not going to be below freezing. By next spring you can see if the tree is putting on new growth and going to make it. Sorry. I might also talk to the folks who put the patio in and advise them that if the tree dies they are going to be held accountable for the cost of removal and replacement.