Dear Extension arborists,

We have a box elder growing right next to our house. I shades our home and keeps us cool in summer. The tree has three trunks, split at ground level. It's about 40 feet tall, nicely shaped and healthy. One of the three trunks directly abuts our front porch, and there are signs it may be starting to lift the porch. Should we remove that trunk? Cut down the tree? Would a general reduction pruning slow down growth of the trunk diameter? We love this tree and hope it can provide many more years of cool shade and general joy. I tried to attach photos, but I keep getting "fileundefined" errors. Thanks a lot for your help. Let me know if you have questions or need further information.