Question
We are replacing a cottonwood tree we had to remove 6 or 7 years ago and have decided to replace it with an October Glory. Not being too savvy about tree planting, my question is two fold. Should we pre-treat the soil with anything before planting, and can we replant close to an area we induced a stump with root killer 5 or 6 years ago?

Answer
The product you put on the cottonwood stump is long gone and will have no effect on the new tree. No need to treat the soil with anything. You may encounter some roots from the old tree but these will be dead but may not have fully decayed.

The new hole for the tree should be dug twice the size of the root ball of the new tree and as deep. Fill with good top soil or potting soil. Mulch around the tree with not more than 3 inches deep of organic mulch and water every third day for the first couple of months if it does not rain. Then water every week through the first growing season.