Mulch is a very important tool in any gardeners’ toolkit. In addition, it does a lot more than simply make beds look nicer. Mulch serves a variety of different purposes that are beneficial to plants around your house. Let’s talk about the different types of mulch that are out there and how they can help you have healthy plants.
There are many different types of mulches out there. Some of the most common kinds of mulches are bark, compost, leaves, newspaper, pine needles, straw, and wood chips. If you are using bark for mulch usually small chunks is going to be better because large chunks are more susceptible to being washed away. Compost can be a very beneficial mulch. What separates compost from the other mulches on this list is that compost is capable of providing nitrogen to plants. Leaves are a good cheap source of mulch for many people. Many times, there’s nothing wrong with taking leaves that have fallen and applying them around the base of plants. The only time when applying leaves as a mulch is not a good idea is if the leaves have a disease in them. Those leaves should be removed to prevent the disease from spreading to the next season. It’s also good if you can shred the leaves before applying them so that they don’t become matted. Newspaper serves as a good undermulch. Placing pine needles or straw on top will keep the newspaper from blowing away. Pine needles look good as mulch. They can make the soil more acidic over time, but that is a slow process. Straw can be an effective mulch, but it’s not as long lasting as some of the other mulches described here. Straw will also sometimes contain weed seeds. Wood chips are a long lasting mulch. They can last two years.
One of the benefits of mulch is weed suppression. When it’s applied thick enough, mulch creates a barrier that blocks sunlight and creates a physical barrier preventing unwanted plants from growing. Once summer is in full effect mulch can go a long way to make your job of weeding easier. Mulch can help with disease suppression in the case of mummyberry on blueberries. Mulch will bury the disease.
Mulch also benefits moisture retention in the soil. When there are hot dry summers the mulch will serve as insulation against the sun and the wind, reducing the amount of water that is lost. The insulation from mulch also helps moderate soil temperatures. That doesn’t mean mulch can keep your soil from freezing, but it can give you a buffer of a few degrees if temperatures are fluctuating.
One thing to keep in mind when applying mulch is the carbon to nitrogen ratio. Most mulches are very high in carbon. For the microbes in soil to decompose mulch they need nitrogen. So, if you apply a lot of wood chips as mulch, those microbes in the soil will need all the nitrogen to break down the mulch, meaning your plants aren’t going to get as much nitrogen. So adding some extra nitrogen to the soil will be beneficial to the mulch and your plants.
Most mulch should be applied 3 to 4 inches. 5 inches for pine needles and 2 inches for wood chips. If you have any questions about mulches contact your local Extension Office or email me at Jacob.Williams@uga.edu.