Nothing makes a landscape look better than a nice fresh coat of mulch. That may be why most people mulch, but there are many reasons to mulch, and most involve plant health. As a rule, many people mulch in the spring, and cosmetically that is fine, but if your plants could speak, they would say, “Please mulch me in the winter.”
Let’s consider nature and its mulching schedule. Nature has been mulching since the dawn of time, and its schedule has not changed in all that time. Nature mulches in the late fall. Why does mother nature mulch at that time of year?
Applying mulch has many advantages besides beautification, and nature knows these reasons.
Reasons To Mulch In The Winter
- The temperature of the soil under the mulch stays consistent temperature. When soil is constantly freezing and thawing, it is unsuitable for plants. Covering the soil with a layer of mulch is like putting a blanket on the ground. Keeping the soil warmer longer allows the plants to grow new roots, providing a healthier root system to absorb water in the summer. Once the soil is frozen, this blanket keeps the soil temperatures from fluctuating if we receive a warm spell. As the soil expands and contracts due to freezing and thawing, it can damage the tender new roots of the plant. This is especially important for shallow-rooted plants such as perennials.
- Mulching in the winter helps to suppress weeds. Mother nature knows that the competition for nutrients and moisture must be reduced for plants to thrive. Applying mulch in winter not only helps to prevent weed seeds from coming into contact with the soil in winter but also helps to prevent weed seeds from germinating in the spring. Weed seeds that fall in the spring will struggle to germinate and grow on the surface of a mulch. More often than not, gardeners get a late start on the mulch in the spring, and mulching late actually acts like a covering that protects weed seeds and helps them germinate. Mulching in winter can reduce the number of weeds without using chemicals such as pre-emergents.
- Mulching in the winter helps protect the organic materials resulting from the previous year’s mulch breaking down. During the growing season, mulch breaks down through its natural process. This organic material provides nutrients and moisture-holding capability to the soil. When you apply winter mulch, it helps to protect the organic matter from running off of the beds during heavy winter rains on the frozen soil.
Types of Mulch
There are many mulch products, and in Maryland, shredded hardwood is the top choice. Shredded hardwoods are available in natural color (No Dye Added), Dyed Brown, Dyed Red Mulch, and Dyed Black Mulch. Many gardeners prefer the look of natural mulch, but dyed products due hold their color longer. Pine fines are also used in areas of garden beds where annuals are planted. The benefit of the pine fines is that when it’s time to change the annuals, the pine fines can be turned into the soil, creating better soil each time.
Shredded hardwood is available in both bagged and bulk. It is essentially the same product, but the bags are typically more manageable for most people to handle without pickups.
In the southern states, Pine needles are a popular mulch type, sometimes referred to as pine straw. Shredded leaves are also a choice for mulching, but this is best reserved for the vegetable garden as shredded leaves break down quickly and become more of a soil enrichment product. Shredded leaves also can contain weed seeds because of the way they are processed.
Using Wood Chips As Mulch
You may be tempted to get some of those free woodchips that tree removal companies are always looking to get rid of. Wood chips should never be used as mulch. Fresh woodchips can contain weed seeds, pieces of poison ivy, or other unwanted plant material. The main reason to avoid using wood chips is that they are fresh, so no composting of the material has taken place. For this decomposition to take place, nitrogen is needed.
Nitrogen levels in the soil will decrease due to the fresh wood chips. Nitrogen is one of the major nutrients needed for plant growth. After mulching with woodchips, you may notice your plants start to yellow, and the growth rate slows down.
Good quality mulch has already been aged, so the amount of nitrogen locked up in the breakdown of larger pieces of wood is much reduced.
Winter mulching is the most significant step to protect your plants from the harsh winter elements. Remember, you get what you pay for, and it is worth spending the extra dollar or two per yard to ensure you receive the highest quality mulch. A 2” Layer of mulch now can make all the difference to your landscape next year.