Last year I planted 3 flowering pear trees. For those who have never heard of the tree (or do not grow these trees) they look like this:
For 2 out of the 3 trees it was very simple to plant the tree as the soil was very good and to this day both are living very well and growing very well. The third one I planted was very difficult to plant; not only was there a LOT of clay but there was a TON of poured cement / crushed concrete. It appears (since this was a newly built house) that the builder just dumped either crushed concrete or concrete itself in this one area and covered it up with some dirt / clay / soil. I tried as best I could to dig a hole and was so tired in doing so I finally got enough dug to place the tree in the hole. This tree was always much weaker then the other two trees and eventually this year died.
So because of the design of these three trees this is the first one in a row that has died. So just taking it out and growing grass would look really odd as I am missing the first out of three trees. So I have to replant one...so I dug this one out and have been using a huge pick to pick as much concrete out of this hole but it appears I am surronded by this crushed concrete.
I guess my question is how far deep or along the sides do I need to keep digging in order to plant this tree correctly? I do not want to end up with the same mistake the first time of my tree dying again. Is there some sort of limit in depth or width I need to go before I can say stop then plant the tree and surround it with good dirt?
With this in mind besides top soil should I add some peat moss / wood chips to enrich the health and promote growth on this tree?