Learned a few things in tonights class, regarding tree protection and so forth. Avoiding planting or sodding grass right up to a tree (string trimmers destroy bark and kill the tree) or edging to the drip line of the tree and mulching to allow proper oxygen to the roots. Ensuring you don't compact or add soil over the roots because it restricts air flow. Things like that, pretty knowledgable class. Not really new idea's but good to have in mind for any new comers!