Laying mulch before the winter gives your soil a head start for the next growing season. It also protects delicate plants, adding the equivalent of a whole zone level to those that might not be hardy enough for the area. Kristin Schleiter, the acting Director of Outdoor Gardens at the New York Botanical Garden, shares some tips to make the most of mulch.
When choosing the type you want to lay in your garden, avoid mulch made of raw wood (because it robs the soil of the nitrogen plants require) and any that are artificially dyed (since they add extra chemicals to the garden).
The New York Botanical Garden prefers leaf mold (pictured above), which you can make yourself in the backyard, and pine bark mulches (right). Other suitable materials include cocoa hulls, straw, even walnut shells—just keep in mind that the smaller the pieces making up the mulch, the faster it will need refreshing. Leaf mold, for example, will deteriorate very quickly and can be laid thickly, but one to three inches of bark mulches will do.
To overwinter delicate perennials, Kristin suggests a cover of evergreen boughs for protection against the elements. Don’t ever layer mulch over plant crowns, or they won’t grow properly come spring. For newly established plants, surround their roots with mulch after the ground freezes for the first time: this prevents them from heaving during the thawing/freezing cycles over the course of winter.
For trees, never let the mulch touch the trunk; leave about three inches of space all around. Those “mulch volcanoes” that many gardeners produce can cause disease and basal rot.
Making leaf mold
Unfortunately, if you don’t have leaf mold on hand, the process takes too long to prepare for this season. But with very little effort you can be laying down a free, moisture-rich layer next year. Pile up the leaves you’ve raked from your lawn in a little-used corner of the yard, and let the microbes do their thing. To speed up the process, run the lawn mower over the pile to break it up and keep the area wet. The mold is ready to use when it appears soft and crumbly.
Once you’ve prepared your flowerbeds, sit back and let the mulch do the work of enriching the soil for next spring and keeping your plants safe.
For more on fall home and yard maintenance, consider: