What is winter mulch and what makes it different from what I do in the spring?
Winter mulch helps protect tender late plantings, shallow rooted perennials and bulbs. The goal is to keep the soil frozen throughout winter and early spring, rather than fluctuating between freezing and thawing. These uneven temperature swings can result in root damage, early sprouting or frost heaving of plants and bulbs out of the ground.
Wait until the ground freezes (the surface should be solid or at least crunchy) to apply a 4- to 6-inch layer of straw, marsh hay or evergreen boughs. If there’s already snow on the ground, keep some mulch ready for when it melts later in the season.
Timing is key. If you mulch too soon, the plants may start to grow and are susceptible to disease. You’ll also create a warm habitat for rodents and rabbits that will then feed on your covered plants.