Forgive me if this has been discussed on another forum but after searching for a while, I couldn't find anything on this topic.

I build a raised bed and filled it with about 60% top soil and 40% compost. I've noticed that a really hard crust has formed on top (about 1 in deep) but the soil underneath is pretty moist. I'm wondering if this is an indication of a poor soil mixture. I don't really want to disturb the plants by mixing around them.

My question is, will mulching around them with pine bark help in any way? Or should I just leave it be? Any suggestions are welcome. Thanks