Do I need mulch?
WHY MULCH?
So, what is mulch and why do I need it?
Sometimes, the best place to start is with a simple definition. So we will do just that. Mulch, as stated by dictionary.com is, “a covering, as of straw, compost, or plastic sheeting, spread on the ground around plants to prevent excessive evaporation or erosion, enrich the soil, inhibit weed growth, etc.” The definition is helpful because it helps describe the uses, and the types of material that can be used. Of course, when we think of mulch, we naturally associate that with wood chips, but we see here that there are many other types including: rock, wood chips, and straw. Essentially, mulch is any form of natural substance than can be used to benefit soil conditions.
As always, our company’s vision is to provide quality through purposeful work. With that in mind, let’s go over some fo the right and wrong ways to use mulch within your landscape.
We know from the definition that mulch has many benefits, but you may be surprised at just how much it really helps. For this I will tag a very useful article written by Anne Gibson from themicrogardener.com. In this article, Anne lists 20 different uses for mulch. We won’t go over all 20, but this should help you gain some additional knowledge on the subject if you’d like to spend some more time on it.
Let's focus on three.
Compost
Erosion
Weed Prevention
PROS
COMPOST
Mulch is a great way to provide compost for your soil. We have heard many clients come to us with problems getting plants to grow. Of course, there are many variables as to whether or not a plant can grow in a certain area. Some examples of potential issues could be: variety of the plant, location of the plant, and so on. After checking the obvious, a great place to start is soil condition. A very common problem we have discovered is poor soil conditions around newer homes. When a new home is built, the first thing that happens is the soil is stripped so that the builders can get to solid, level ground. This solid ground is known as subsoil. When this happens, the fertile black topsoil is set to the side for reapplication after the home is built. Lets refer to this diagram from www.charim.net.
As you can see in this photo, the soil is typically segregated into four main categories. Of course, a horticulturist would be able to go into much greater detail, but for the sake of this post, we’re going to keep it simple. On average, there is about 12” of good, fertile soil in a natural setting. Standard building practices call for 4-6” of top soil be reinstalled. Unfortunately, most builders will use even less. At this point in the new build, we have removed the fertile soil, compacted our subsoil, and not reinstated the ground properly. When planting new grass, the depth of fresh soil isn’t typically a big issue as long as the soil that was replaced is clean and full of good nutrients. However, plants are a different situation. Most native plants to Illinois have deep root systems which help during dry summers and cold winters. When a plant is young it needs lots of good, deep soil to help establish itself. When we install a new plant at a newer home, we almost always place the base of the plant on bad soil due to how shallow the black dirt is. Although plants are adaptive in most situations, they can struggle to produce a healthy root system in hard, nutrient depleted soil. This is where compost can come in handy. Over time, soil conditions will naturally improve, but compost can help speed this process along. By maintaining moisture, and using decaying matter such as mulch chips, the soil will naturally break down quicker. This will help give the plants a better starting point by providing a deeper layer of top soil to work with.
ERSOSION
Do you have problems with areas of your landscape washing away? Assuming that the yard has been graded correctly, erosion is almost always due to poor soil conditions, and many times it can be fixed through erosion control. Sometimes this is as simple as using a plastic/fabric barrier under your mulch or rock. However, a more natural approach is just simply using rock. This can create an awesome look while also controlling your erosion problem. Here are a few examples.
On this particular project, we chose to use both fabric and rock to help with erosion, weed control, and keeping the water clean. This was the favorite projects we’ve ever done. We got to use a little bit of creativity and solve a real problem. By using the fabric, we essentially created a filter for the soil before it washed into the water, allowing the client to keep a much cleaner area for their fish and wildlife. Also, by using rock around the perimeter, we eliminated the possibility of the mulch washing into the water after a heavy rain. You can view the finished product below.
WEED PREVENTION
If you’re having a problem with stubborn weeds, mulch may be the best answer. Weeds will always be a problem, but being proactive can make a big difference. Mulch creates a suffocating barrier for old weeds. The weight, and lack of sunlight, will kill off a lot of the existing weeds. Of course, some weeds will find their way through, but the impact is much greater than doing nothing at all. If the weeds persist, it is likely because of new growth on top of the mulch. With constant attention and diligent work, you can eventually get it under control.
CONS
COMPOST
Did you know that it is possible to over mulch? Let’s focus on two possible issues with over mulching. First, when mulch decays, it releases nutrients into the soil. One of those nutrients is nitrogen. Nitrogen is vital to plant life, but it is possible to have too much. Check out this awesome article by cropnutrition.com. In this article, the author discusses the uses of nitrogen, application practices, and the effects of nitrogen on plants. In part of the article, the author shows how using too much nitrogen can actually make the plant dependent on nitrogen to a point where it requires it to survive, thus resulting in a weak plant. Refer to this article written by Amy Rodriguez. homeguides.sfgate.com. You can see more negative effects to too much nitrogen such as water contamination. Of course, to much nitrogen would rarely be achieved simply by using to much mulch, but it is something to keep in mind. Second, you can actually suffocate your plants. Just like we said, mulch can be used to suffocate weeds, mulch can also suffocate your plants. Too much mulch actually causes the base of the plants to break down over time and rot from over exposure to decaying matter. Did you know you can actually kill your trees this way? We’ve noticed a trend with people piling their mulch up the tree in a pyramid shape. Although some people may like the look, you’re actually killing your tree. Just like small plants, trees need to breathe as well. By covering the base of the tree, you once again, you create the possibility for decay.
EROSION
Erosion control in and of itself, will never have a real downside, but the tactics you use to fix the problem could have poor outcomes. When deciding how to handle your project, you may want to consider a few things. First, you need to find the origin of the problem. You wouldn’t want to spend hours on a project only to find that the problem still exists further upstream. This may sound simple, but some problems can be hard to locate. Second, decide which products you should use. Sometimes, fabric under your mulch is more than enough. Other times, you may need to install a french drain or some other form of drain that’s meant to handle large volumes of water. Staying consistent with our topic; however, we will focus on the materials such as rock or stone. Some of the best drainage stone you can use is basic river rock. This allows water to flow freely without creating a stream. Lighter materials like mulch will wash out. As the washout occurs, the water carves a path and gets stronger as it flows. The advantage to stone is that it stays stationary, assuming the current isn’t to strong. The stone breaks up the flow of water and allows it to filter into the ground at an even and consistent rate.
WEED PREVENTION
Weed prevention can be tricky, but taking the right approach can make it much easier. At this point in our company, we feel it is best to use as natural of a process as possible. That being said, sometimes chemicals and man-made products are necessary for the best results. Our philosophy is to take a thought-out approach to everything. For us, that generally means balance. If we can pull weeds, we do. If the weeds have overrun the property, sometimes we have to call for a more aggressive approach. One common tactic is to use weed barrier or “fabric”. Although it can be effective, it’s not always the best choice. Over time, the barrier will decay. This is good and bad. It’s good because it helps the landscape return to a somewhat natural state but bad because we’ve now filled the area with plastic or man-made substances. Now we have problems with weeds again. In some cases, such as when you use stone, it is necessary. This is the only long-term way to fight against a bad weed problem under a product such as river rock. It also helps with erosion as stated before. The question is, do we want to use it when it’s avoidable. Of course, this is up to you as an individual, but we say no. Let’s look at it this way. Weeds require soil to grow. If we place fabric down, and then place mulch on top, we’ve essentially just created a seed bed for new weeds. As we stated before, mulch is great for suppressing the growth of existing weeds already. With this in mind, it doesn’t seem very useful to put fabric underneath mulch. Instead, let the mulch do its job of providing nutrients, retaining moisture, slowing erosion, and suppressing weeds. The maintenance can be left to us.
Written by: Aaron West
1/18/19