A box turtle hovered next to my flower bed for two days, then made its way into the bed close to the house where it snuggled down in the mulch. It has been like this for a couple of days now. I'm concerned about dehydration. What do you think?
Box turtles have become rare so you are honored to have one. They have distinct territories which they orient themselves to when young and will not survive if moved out of that territory. So, we have to let them figure things out where they are. That means not moving it. (Or, when they cross a road, helping them to keep going in the direction they chose--though we can place them farther from the road where it is safer.)
In your turtle's case, it may be preparing to lay eggs, which would be fantastic. You can put a water source nearby if the area seems dry. A low saucer of water or shallow container with a low lip or flush with the soil surface would be great.
Be sure to avoid using any pesticides nearby. Read up about what they eat. Those food sources need to be non-toxic.