Autumn may feel like a winding-down time for gardeners, as plants begin to go dormant or enter the final stages of their life cycle. It may look like most of the work is done for the year However, there are still plenty of important tasks to keeping working on in your garden, and maintaining your mulch layer is one of them.
Bark mulch not only thwarts weed growth, it also holds in moisture and moderates the soil temperature. That’s especially important for the upcoming cold winter when perennials are vulnerable to damage from snow and ice. Think of a new layer of mulch like a winter coat for your plants.
As always, your mulch layer should be at about 3 inches in depth. Too much will create an impassible barrier for moisture on the surface and in the ground. Check the health of your existing mulch first and remove any that appears moldy or diseased.
Not only will this mulch insulation protect your plants from the cold winter, but it will also help prevent frost heaves from harming the soil and structural integrity in your garden. Frost heaves are formed by water entering the soil and expanding when frozen, pushing materials around, and the mulch will prevent that from happening.
But don’t think autumn mulching is only about preventing problems in the winter. Weeds can still grow in September and the fluctuating temperatures and moisture levels need to be controlled. Don’t spend all summer and spring working on your garden only to abandon it in the fall, as a little autumn preparation can make things a lot easier next spring.