Add a dish of fresh water daily to complete the backyard wildlife refuge. Christmas tree limbs can be laid over perennial flowers such as mums and bulbs to insulate plants against wind, severe cold and soil heaving from freezing and thawing temperatures. Evergreen branches stuck into the ground like a picket fence around broad leaved evergreens such as holly or rhododendrons will protect plants from drying winter winds. Christmas wreaths are a perfect size to lay around many perennials as a mulch. In the spring use the old Christmas tree skeleton as a trellis for scarlet runner beans or climbing sweet peas.
Vines quickly cover the tree for a beautiful display.
Or grab the neighbors trees and make a rustic entry way to your garden. Let a climbing rose drape over it. Chipped needles and limbs make excellent mulch around trees and shrubs. A commonly asked question is whether pine mulch is toxic to plants. This mulch myth probably originates from some observant folks noticing few plants grow under evergreen trees in this area and then mistakenly concluding the pine needles must be toxic.