Mulch is one of the most popular garden and landscaping products. Mulch makes spaces look great and generally require less maintenance since there is less mowing and weeding to do. But there are also some disadvantages to different types of mulch. Here’s what you need to know about types of mulch, as well as some tips for applying mulch to your Iowa landscaping.
Advantages and Different Types of Mulch
There are two main categories of mulch: organic or inorganic mulches. The key difference is that organic mulch decomposes over time and turns into soil. Inorganic mulch does not decompose, though it may slowly break down into smaller pieces over time.
Organic mulch types include:
- Grass clippings
- Wood chips
- Pine needles
Inorganic mulch types include:
- Plastic sheeting
- Landscape fabric
A few advantages of mulch are that it usually helps to retain moisture in the soil, slows or prevents the growth of weeds, helps regulate soil temperature, reduces watering, and helps repel some pests.
The main advantage to organic mulch types is that they improve your soil over time because they break down and add structure, nutrients, and air to the soil, making it healthier. But the fact that they decompose can also be a disadvantage because it means you’ll have to top them up every few years, forever, to keep things looking nice and keep weeds at bay.
The main advantage of inorganic mulch types is they last a long time. You don’t have to top them up that often because they don’t decompose. Rock mulch can look nice for decades if you stay on top of weeds, whereas bark mulch will need to be top-dressed in just two years and may look pretty messy by three years.
The Disadvantages of Inorganic Mulch
Disadvantages are more specific to certain types of mulch. Here are some of the disadvantages of inorganic mulches.
Rock mulch can absorb and reflect heat from the sun, making an area very hot and dry, so not many plants can survive in the area. Rocks also do not add any nutrients to the soil over time. If a rock mulch layer isn’t thick enough, the weeds will grow right through in no time and can be more challenging to remove. It’s also quite heavy and quite physically demanding to apply.
Plastic sheeting can suffocate the soil, killing not just weeds but also other plants and all the soil’s microorganisms, effectively killing the soil. Plastic sheeting also does not allow water, air, or nutrients to get down to the soil.
High-quality landscape fabric keeps weeds down, but the roots of shrubs and trees will grow through it eventually, making it extremely difficult to remove in the future. Cheap landscape fabric tears easily, breaks down quickly, and only suppresses weeds for a year or two, and then it’s difficult to remove. High-quality landscape fabric is expensive.
Rubber mulch, while produced from recycled materials, doesn’t have much long-term study done on it. There is the risk of rubber releasing chemical compounds into the soil, it also doesn’t break down over time, and it doesn’t improve soil, and it’s also one of the most flammable options.
The main disadvantage of inorganic mulches is the upfront cost: all inorganic mulch types are generally more expensive than organic mulches, but they also don’t have to be top-dressed every 2-3 years.
The Disadvantages of Organic Mulch
The disadvantage of leaves as mulch is that if you leave them as whole leaves, they blow around a lot, and once they stop blowing around, they can start to look messy, slimy, and dirty. If you mow over them to chop them up, it takes way more leaves to create a decent mulch layer. You can’t exactly buy more leaves to add to your mulch, although you could volunteer to rake all your neighbor’s yards to collect their leaves. If you don’t have lots of deciduous trees, you’ll have difficulty getting enough leaves to mulch anything.
Straw can be a convenient type of mulch, and it’s often used around things like strawberries to keep the fruits from rotting on the soil. The disadvantage of straw is that it doesn’t look that nice. It looks a bit messy. It’s also not that nice to walk on. And while it does break down and improve the structure of your soil over time, it may also contain the seeds of weeds that grew in the farmers’ field. It also takes a long time to break down, and it can be slippery to walk on when it’s wet.
The disadvantage of grass clippings is that if they’re piled too thickly, they get really hot, which can make the soil underneath them too hot or even potentially start a fire. If they’re spread too thin, they don’t do much to keep the weeds down. When grass clippings dry, they can blow around a lot and are hard to keep tidy, and they don’t look that nice, though they are soft to walk on, and it’s free every time you mow your lawn.
Compost is an excellent mulch type that should look pretty similar to ordinary soil. But, it can be hard to get enough to mulch a large area, and it takes time to create from your own compost pile. Getting enough to mulch your whole garden is challenging. It may not keep weeds down that well since it’s full of great nutrients that plants need to grow.
Wood chips and bark chips are one of the most common mulch options. They’re overall an excellent mulch, but they do have a couple of disadvantages. One being the mold that can grow in and on bark or chip mulch. Slime mold is pretty gross looking, although harmless. Bark and woodchips also take a long time to break down and improve the soil, but in just 2-3 years, they start to look pretty tired and need to be top-dressed.
If you’ve got lots of evergreens, chances are good they’re making their mulch when they drop needles. Getting enough pine needles to make a thick enough layer of mulch to suppress weeds is challenging.
They’ll make enough for the area directly underneath them, but collecting more for other areas of your yard is going to be a slow process. Pine needles can also acidify the soil over time as they break down. It’s not a fast process, but it does happen. Pine needles are also called needles for a reason. So you’ll need to wear thick gloves if you’re attempting to plant under it, and it’s not pleasant to walk on, especially in sandals or barefoot.
Generally, organic mulches are more affordable upfront, and they’re a little easier to apply, but they have to be topped up every few years.
Bottom Line: Mulch is Worth the Investment
In general, the advantages of mulch far outweigh the disadvantages. It comes down to your personal aesthetic preferences and your budget. Mulch will help keep your yard tidier; it can improve the soil over time, it can reduce how much you need to water plants, trees, and shrubs, keep the weeds down, and reduce the amount of lawn area you need to mow, water, and fertilize.