Can I use my Christmas tree for mulch?
The boughs of fir, pine, spruce, and other evergreen trees are a good insulator for dormant perennials. Unlike some winter mulches, like unshredded leaves, they don’t pack down into a solid, oxygen-excluding layer. And when spring comes, they’re easy to rake aside.
Discarded Christmas trees appear curbside at an ideal time for adding winter mulch in my Zone 6 garden. By late December, the ground has chilled (if not frozen an inch or two deep) and plants are dormant. Hopefully, any field mice in the neighborhood have settled down elsewhere for the winter and won’t find habitat in my mulch. I scavenge the neighborhood before trash day, bringing home five or six trees to cut apart.
It’s quick and easy: Just snip the tree’s branches off with loppers. Place the boughs over the crowns of perennials or around roses.
The purpose of winter mulch is not to keep plants warm but to keep them consistently cold and dormant. Unmulched plants are exposed to temperature fluctuations, alternating between overnight freezing and daytime thawing when the sun hits the soil. Some plants shrug off these repeated temperature changes, but anything of marginal hardiness will appreciate the extra protection it gets from a layer of evergreen boughs. —Doug Hall