I have a tall stag's horn sumach which has leaves and flowers only about 20ft above the ground, on the end of three bare woody trunks. I notice now that the tops of two of the trunks have been frazzled, possibly by the heat? But the third looks quite healthy. I would like to reduce the tree and hopefully rejuvenate it, bringing the interest of it down a bit closer to eye level. Any advice? I could take the whole thing down and train one of the many suckers in its place, but the parent is in the spot at the back of the border that I'd like it to be, and the suckers are further forward, so they'd take over the whole border.