Our 20-30-year-old Ash tree has rising ground at the base and lower?

This could be a sign of root and/or soil failure. If this is the case, then the tree would need to be removed. Some things to check: is the soil "soft" where the ground is rising? Is the tree leaning more now than three to five years ago? Was there any trenching done around the tree (i.e. roots cut)? This is very uncharacteristic of ash trees, usually they drop large branches, but that doesn't mean its impossible. We would need to look at it to be sure. You can click here to make an appointment.