The why and how to mulch your fall garden.
Now that we’re well into November and we’ve had our first snowfall, it’s time to prepare your perennials and rose garden for the season ahead. Because Colorado’s winter weather is rarely predictable, gardening in our area presents unusual challenges, including temperature fluctuation, dry wind, and inadequate moisture. Minimizing these negative influences on your plants is where the organic mulches come into play.
The primary reason for applying mulch at this time of the year is to keep the ground cold and stable and maintain plant dormancy, especially during the brief warm spells we typically get through the course of our normal winters. The right mulch will not only stabilize the ground, but conserve moisture, reduce plant damage and protect the soil.
Garden and landscape mulches are available in two types, organic and inorganic. Organic mulches include shredded wood, fine bark, aged compost and leaves. Inorganic mulches include rock, gravel and artificial products. Technically, both types of mulch will work. Inorganic materials such as stone and river rock don’t break down, so they typically don’t need to be reapplied every year.
Inorganic mulches are generally applied with a fabric barrier to discourage weeds from growing, as well as keep the mulch in place. While this helps to reduce maintenance, it also hinders moisture absorption, adding nutrients and making soil amendments. Long term, your plants don’t do as well.
If you want the most effective mulch in terms of winter plant protection, moisture conservation, soil stabilization and enrichment, choose organic mulch. For perennial beds and roses, shredded bark and fine bark work well and provide a natural look. The goal is to apply a three to four-inch layer of mulch to your perennial beds and roses, once the ground turns cold.
A two cubic foot bag of shredded cedar or Gorilla Hair mulch will cover approximately six square feet three inches deep.
You may have read or heard that using bark mulches will lock up the nitrogen in the soil. Organic matter applied to the top of the soil decomposes slowly, without affecting available nitrogen levels deeper in the bed.
Using compost as mulch not only helps insulate plant roots against extreme temperatures but improves soil as it breaks down. Spread a two-to-three-inch layer of high-grade compost on top of the soil. Compost will gradually break down through the winter, enriching the soil with organic matter and nutrients.
Keeping the plants in your landscape healthy through the Colorado winters can be challenging but by applying organic mulch at the right time, your roses and perennials will be better protected from the winter weather.
