Care of transplanted Holly trees?

[gspren]

Yesterday I dug up some 18" to 30" Hollys out of my woods and replanted in my new woods about 8 mile away so they were only out of the ground an hour or so. The dirt where I put them isn't the best so I mixed in a little peat moss. It rained most of today and it's going to get cold later this week, should I mulch around them with straw to hold in some ground heat, do something else, or just let nature take over?