Mulch should not be put up against tree trunks. Check all plants for moisture and water thoroughly if necessary. Check every two days for dryness. If you will be going on vacation, ask a neighbor to water them if necessary. Plant them as soon as possible.
All plants benefit greatly from well prepared soil.
Dig a hole at least twice the size of the root system. Use your existing soil and mix well with soil conditioners such as peat moss, leaf compost, Compro, Clay Cutter, etc. Be sure to loosen the root system of the plant either by hand or with a cultivator or knife. Pack the soil mixture firmly around the rootball and water thoroughly. Cut twine and any plastic burlap.