Question
Hi, in my garden I have a very large flowering cherry tree (pink)it looks like it is dying, as the branches have started to fall off, no leaves remain on the lower part, but there is green leaves at the very top part of the tree.  I have recently renovated the garden and think I have raised the ground around the roots by about 6", if it is the ground that has caused this, what do you recommend?, to try and save it, would digging out around the base make a difference, should I cut the dead branches down? any advice would be greatly appreciated.

Answer
The fill and the renovation around the roots of the tree caused the roots to start to die and thus the foliage is dying back. The adding of 6 inches of soil especially if it was added near the trunk compressed the air spaces in the root zone and killed the small roots. If there was also digging during the "renovation" this could have damaged the roots (the roots of tree are in the top 18-24 inches of soil and any digging near the tree will damage the roots. I would try removing at least half the soil and make sure that the soil is removed from the base of the trunk back to the original ground level. And then about all that can be done is water it once a week when it does not rain and wait and see. You could go ahead and prune off the dead branches but I would wait and see if the tree makes it. (maybe wait about a month or six weeks and then if the tree is still alive prune the dead limbs off). To check and see if a branch is alive start at the end of a upper branch and scrape a small bit of bark off the branch and if the color under the bark is green then the branch is alive at this point on the branch. If the color is brown then it is dead at this point on the branch-continue down the branch until you find green. If no green is found on that branch it is dead and can be pruned off. Do this on any branch that you are unsure is alive or not.