How Much Mulch is Too Much
Mulching is one of those things that nearly everybody just does, as a matter of routine. Often, we don’t take time to stop and consider what the benefits and risks can be. People will talk about “Mulch Volcano’s” from time to time, but do you know what your mulch actually does, and how? Many people know that it helps to prevent weeds and looks nice, but it’s also there to enhance the soil of your plants, hold moisture, and help moderate the soil temperature. The problem is that, frequently, when we apply new mulch year after year, we create the same circumstances that hurt so many of trees planted in mulch volcano’s. Perennials, in particular, are sensitive to over-mulching. Too much soil moisture, overheating under the surface, and the properties that make it a weed preventer can all work to turn mulch into a “plant preventer”.
At Old Field Landscapes, we usually recommend going with a dyed mulch product so that your mulch will continue to look good as it breaks down over time. This allows you to go longer without reapplying more mulch. The most important thing I’ve found with mulching is prevention of buildup. It’s just like everything else in life, too much can be a bad thing. Your shrubs may be feeling as though they’re being buried alive. Even decomposed mulch can create this unhealthy build-up. If you can wait two years between mulching, it could help your plants tremendously, and create a much more sustainable routine (costing you less money!), when using bark based mulches.
Two inches is a good starting point for bark based mulches, usually a depth of 2-4” is recommended, but unless you plan to do some serious yard work to pull back and remove excess throughout the year, anything more than two can hurt your plants. Be aware, as well, of where your mulch is being placed. Mulch should be kept away from the base of all plants, not just trees. Mulching benefits the parts of plants that are unseen, underground, it can damage the parts that are above ground, and this is how it works as a weed preventer.
As is generally the case, if you’re applying new mulch every year for aesthetic reasons, one inch is usually a good amount to put down. If the mulch has over-accumulated over the years, consider mulch removal. Typically, when there is a buildup of mulch, you will find some hard compact layers beneath the surface. These layers need to be broken up or removed, to allow for the all-important porosity in your soil, which facilitates air and water movement. Whatever method or mulch you choose for you home, Old Field Landscapes can help, with a wide variety of mulches to choose from and the knowledge to help you choose what is best for your plants.
Here is some more info on over-mulching: