There’s never a season to mulch. You can even mulch, add mulch or fluff up mulch now, in the middle of summer. Mulch is nature’s filter and insulator. In a forest, nature provides the mulch in the form of fallen leaves and branches. As they decompose, they become nutrient-rich humus and return essential nutrients to the soil for the living plants to absorb.
Cultivated landscapes don’t have the same luxury as natural landscapes. Mother Nature leaves it up to cultivated landscapes’ owners to provide the necessary soil amendments. That’s why it’s so important to learn all about the various types of mulches available and their benefits.
Mulch can be divided into two main categories – organic and inorganic. Inorganic mulches include such materials as various size stone and ground-up, recycled rubber. Stone is purely decorative. Recycled rubber is used on playgrounds as a cushioning material to protect the children. Inorganic mulches have no environmental benefit.
Organic mulch includes such materials as ground wood chips, various types of bark, pine straw and compost. You can buy bags of bark in garden centers and you can make your own compost. Pine straw is bagged pine needles. It’s popular in the south but is not used much in our area. Tree care services sell ground wood chips in bulk, by the cubic yard.
My preferred mulch is ground wood chips. This form of mulch is made from debris from tree pruning and removals. This keeps thousands of cubic yards out of landfills and puts them to work protecting landscapes. To convert chip to mulch we double or triple grind them and let them age until they take on a blackish color. Some companies add dye to give the chips the red or other color you see in some yards. Dyes, however, may contain chemicals that can damage plants.
Organic mulch insulates, or moderates, the soil, cooling it down in summer and allowing it to retain heat in winter. Plant roots don’t like wide temperature fluctuations. Organic mulch also holds water and releases it over time. More water from rain or melting snow is available for plants to absorb. Without organic mulch, much of the water from a heavy rain would leach away before plants could absorb it.
If you have organic mulch and it looks as though it’s disappearing over time, that’s because it decomposes, returning essential nutrients to the soil. As it decomposes, just add more mulch. It should be two to three inches in summer, spring and fall and three to four inches in winter. Wait until the leaves drop in the fall and they’re cleaned up before spreading the winter mulch. And make a note to remove any excess in spring.
When spreading mulch, resist the temptation to form mulch volcanoes by piling it up against the trunks of your trees. Although popular, mulch volcanoes are bad for the tree. The mulch volcano is full of water, which is an excellent environment for fungi, including rot fungus. If there’s even the slightest crack in the bark, water can carry the microscopic rot fungi into the tree. Mulch volcanoes are also good places for rodents to hide while they dine on your valuable trees.
Applying organic mulch to your landscape is replicating a natural process that takes place in the wild. That’s why mulch never goes out of style.