You mean "transplant"...ummm, okay this is the ideal time of the year to transplant smaller trees. Not sure how large the one you found is but be prepared to dig deep and get at least 3/4 of the roots and if possible give it lots of water before digging it out and especially AFTER you transplant it. Black walnuts are very slow growing, the smallest one I have is at least 15 years old and is still only 18 feet high and has never produced a nut yet. The leaves are very small and these trees are one of the last to grow leaves in spring and one of the first to drop them in the fall. DO NOT plant a black walnut near a garden or flowerbeds....the leaves contain a compound (juglone) that is deadly to many flower and vegetable species...especially tomatoes. Another thing...besides the small messy leaves, they drop long leaf stalks which are great at clogging gutters.