For trees, take a spool of rope or string. Wrap the string around the width of the tree. Place one end of the string at the base of the tree and the other end perpendicular out as far as the string will reach and circle the tree measuring the circumference to apply HGO. You can till it down into the soil a few inches and also put down 2” of top dressing. Water at the base of the tree, the circular area around the tree top-dressed with HGO will create a container of water helping it to feed down into the soil around the trees roots.