In order to make the best mulch choice, it’s important to understand why we use mulch at all. Certainly, mulch gives your planting beds a clean and well-maintained appearance, and contributes to your home’s curb appeal. It also prevents weeds from sprouting — not only from beneath the layer of mulch, but also from airborne weed seeds that are floating around, looking for the perfect patch of soil in which to germinate. Mulch also maintains soil temperatures. This is very important in the summer, when strong sun rays can heat roots systems and inhibit water absorption, and critical in the winter, when cold temperatures freeze the top layer of soil at night, and the sun warms and defrosts it during the day. This rapid freeze/thaw cycle can cause plant roots to swell and burst — not a happy thing for plants at all!
The two most common mulches in our area are shredded bark, and processed wood. Shredded bark mulches are usually a blend of pine, spruce and hemlock. The color is a natural rich brown, and doesn’t fade through the season. It’s a little more expensive than processed wood because there simply isn’t as much bark on the outside of a tree as there is wood inside. Shredded bark mulches mat together to form a barrier against weeds, while allowing moisture to penetrate evenly. They’re not nearly as attractive to wood boring insects as processed wood mulches are, and when they eventually break down, they provide a rich layer of compost to your planting beds.
Processed wood mulches are usually comprised of chipped wood, twigs and brush. The problem is that wood will turn gray fairly quickly, so wood mulches are nearly always dyed. The red, deep brown and black mulches you see in landscapes are fairly likely to be dyed products, which will fade throughout the season. While there’s no evidence that dyed mulches will harm your plant material, there’s plenty of research suggesting that they’re far more attractive to wood-boring insects such as termites and carpenter ants. Finally, wood mulches don’t form a protective mat like bark mulches do, which makes them less effective as a weed barrier, and not as reliable at water retention.
At DLTC, we spread hundreds of yards of the best shredded mulch available every year. Yes, it may be a bit more costly than dyed wood chips, but the benefits of a good mulch far outweigh the detriments of a less-effective product. We also believe strongly that mulch should not be the star of your landscape — your plant material should. Mulches that are strongly colored steal the scene, and actually detract from your landscape’s appeal. We’re always happy to answer questions you have about mulch, or any other aspect of your landscape.