Originally Posted by Duekster
There are concerns about putting a lot of material on tree roots. Some oaks are more sensitive than others. I am more concerned about the root flare and trunk of the tree being covered. Have 0" next to the truck and taper out up to 5" on newly planted trees. 0" at the to 3" around the tree is you must. I just keep the grass off my trunk and keep a bare ring 24" or less around the trunk of my trees.
I do not use pine bark mulch. IMHO, they do not have the break down well, ammend the soil. Native Hardwood mulch is best. Cedar is second best. I also like Bois D' Arc Mulch very much as it is the hardest native tree around here and considered a scrub tree.
I do not use a Pre-Em on Beds for the most part. If it is a new bed with large shrubs it can be helpful the first season or two.
Sorry for getting off topic here and have more questions pertaining to the tree's so cary on and I'll start another thread.