It's tree-friendly, works great, and lets you focus on other projects. But don't wait until it's too late--you want to get this scheduled WHILE IT'S STILL RAINING!
Once it quits raining, you'll have to water it in by hand, and by then, the weeds will have sprouted anyway. Keep them from sprouting--don't wait until you see them!
Don't forget the shrubs & roses--these plants harbor a lot of overwintering insects and egg cases that can't wait to hatch out and start sucking your plants dry. The dormant oil (mineral oil) smothers them, halting bad insects before they can damage your plants.
Ditto for Copper--this gives your prized roses, dogwood trees, and other plants a head start against fungal infections.