is it okay to completely cover my tree with a bag or just the soil. I need to dry it out. I live in a commnity-type area at my college and whoever waters the flowers under teh tree where I keep my bonsai, keeps watering it. so I need to dry out the soil. how can I do that without moving it?

thanks.
Also, is it okay to take it out and check for rotting roots? and whatdoes rotting roots look like? and do repot after I take it out and check for rooting roots, or just replace it back inthe the pot?
Thanks!