Mulch. It’s a garden staple that nearly everyone has heard of. But, did you know that there are a multitude of different materials that can be used for mulch and not just the traditional wood chips? It isn’t just great for adding “trim” around trees and shrubs either. Plus, did you know that some types can be hazardous to not only your plants but your canine companions as well?

If you’ve been considering your own mulching project but aren’t sure where to begin, we’ve got you covered (pun intended). This post will cover several popular mulch choices, their uses, mulching benefits, and even which ones to avoid if you have pets sharing your outdoor space.

mulch in wheelbarrow

What is mulch?

Mulch is loose material or sheets of material used to cover soil in certain areas. This can be anything from gravel to large bits of cedarwood. Mulch has a multitude of uses and benefits.

Uses for mulch

By now, you’ve probably seen mulch used in a variety of ways. Gardeners love using it in their flower beds and food gardens to keep weeds at bay, setting themselves up for less work in the hot summer months. It is also a cost-effective and eye-pleasing way to landscape around trees and shrubs. Bases for walkways and paths can be created with several different types of mulch material. Have you ever seen a slope or hillside landscaped with mulch? Other than creating an eye-catching display, it was likely implemented to prevent erosion.

Now that you know what kind of projects mulch is useful for, what are some of its benefits?

Benefits of mulch

Perks of using mulch are as varied as their uses. As mentioned above, it is great for natural weed control. Weeding is usually not the most enjoyable garden chore, so why not stop them before they start? You may still have a few tenacious ones pop through occasionally, such as dandelions, but it sure beats having a whole garden full of unwanted plants trying to compete against your fruits and veggies!

Mulch also helps immensely with water needs. Certain types, namely wood, helps with moisture retention. This keeps water available to your plants without getting them too wet, which can cause stem rot. Mulching is also a good way to practice water conservation. You save on your water bill by not having to water your precious plants as often!

While you do need to replace or top off any organic type of mulch regularly (sometimes yearly), think of it as composting the entire area you have mulched. Materials such as wood, leaves, grass, and hay break down over time. These natural materials improve soil quality by adding nutrients back as they decompose.

Mulch is also a great addition to planting beds in Indiana because it helps protect plant roots from temperature extremes and fluctuations, something we are all too familiar with in the Hoosier state!

Finally, no matter what style you choose, it can add some much-needed color and texture to your landscape design to give it depth and emphasize natural beauty.

Types of Mulch

If something can be shredded, is safe for plants, and functional, it can probably be used as mulch. Some people even use shredded newspaper in a pinch! Mulches are generally broken down into two groups: organic and non-organic. Here are a few of the more commonly used types in each category:


Wood Mulch – This is the most widely known type of mulch. It is best used in areas where you won’t need to move it around, such as flower beds and around trees, shrubs, and bushes. Wood mulch can be shredded or in chunks. It’s worth noting that the shredded type breaks down faster but can be better for overall soil health.

Pine Straw – If you have a lot of shredded pine needles on your property, you can put them to good use. They’re easy to use in planting beds during the non-growing seasons to prevent weeds. They’re actually more beneficial to the soil than wood mulch too, adding more nutrients as it decomposes. Additionally, pine straw can add a nice red color to landscapes without using dyed mulch.

Grass Clippings – These are great because they are free, but have a lot of drawbacks. One being that they mat together, not allowing much water to seep into the ground. Grass clipping are best used for preventing weeds in non-planted, open areas of your lawn.

Shredded Leaves – Leaves are free and abundant in most places. They are perfect for laying out in your garden or planting beds after your final harvest to keep weeds at bay during the rest of fall and early spring.

Straw and Hay – A little bit of hay can go a long way! Gardeners have been using hay and straw to go around the base of strawberry plants for years; and for good reason. It keeps weeds away, is relatively inexpensive, and will last all season long.

Newspaper – Another readily available and inexpensive material, newspapers are best used as an alternative to plastic or landscape fabric. Cover with another layer of a different type of mulch for maximum results.


Stone and Gravel Rock mulches are like wood chips in that they are best used in “finished” areas (established plants). These make a great addition to landscaped areas next to sidewalks, rain gardens, or even the base of a pathway.

Plastic – This option is not exactly eco-friendly, but it does do the job (PLEASE AVOID). Plastic sheets are generally placed as a first layer before another type of mulch, usually wood chips, is placed on top. These sheets add another layer of protection against weeds.

Selecting the Right Mulch

With all of the various mulch options out there, it can be hard to decide on the best one for your needs and specific project. Here are a few pointers to keep in mind while shopping around for or planning your project.

  • If you’re set on wood mulch but would like to not have to replace it quite as often, look into cedar mulch. It’s more expensive than most, but it lasts longer due to its resistance to decay. The natural oils in it also work as a natural insect repellent.
  • Another way to avoid topping off and replacing your mulch for longer is to invest in larger chunks since they will take longer to break down. Bark will also last longer than shredded wood mulch.
  • If improving your soil is one of your main goals, consider aged organic mulch that is already partially decomposed. It will continue decomposing and protect your plants.
  • Organic mulches in low-lying, water-prone areas can lead to disaster. These types can actually retain too much moisture, causing plant rot, diseases, and even slug infestations. Areas like this are better suited to a rock or gravel to help with drainage.
  • Stone mulch is also beneficial in preventing washouts and erosion, making them an ideal choice for sloped areas.
  • Mulch comes in many colors, shapes, and sizes. If you’re not sure which is the right color to go with your landscape design, check out this article. Here are some other important notes on choosing and implementing the right mulch for you.

Types of mulch that can be dangerous

Care should be taken when choosing your mulch. Unfortunately, there are some out there that can be harmful to the environment, your plants, and even pets.

It probably comes as no surprise that plastic can be detrimental. It leaches contaminants into the soil as it breaks down and can kill good microbes and even roots if you don’t poke holes in it.

Recycled tires used to make the rubber mulch you see on many playgrounds nowadays can also leach harmful chemicals into the ground over time, which can hurt plants and even some wildlife. They can also emit VOCs (Volatile Organic Chemicals) into the air when they get very hot.

Though CCA treated wood is no longer a practice that is allowed, dyed mulches is usually made from recycled wood, which may have come from some of this old treated wood.

If you have dogs, avoid cocoa bean hulls. It can be toxic if they happen to chew on it, which some dogs seem to love doing. It’s also a good idea to avoid pine needles if you have dogs. Not because it is toxic to them, but it can cause internal damage if ingested.

Organic mulch should smell like wood or compost. If it smells like rotten eggs, vinegar, or any other unpleasant stench, don’t use it…At least not right away. It can be cured by leaving it sit out in the sun in thin layers for several days and even watering it to remove toxins faster. (You can find more information on toxic mulch here.) Sour mulch will severely damage your plants or even kill them.

If you’re considering colored wood mulch, but aren’t sure about the safety of the dyes, this article should help answer your questions.

One of the best things you can do to be sure your mulch is up to snuff is ensuring it is certified by the Mulch and Soil Council.


Need help with your own mulch project? Have questions about which mulch to use? Talk to us! Greenscape Geeks’ friendly and professional team members are happy to help with your landscaping dilemmas. Give us a call, email, or schedule a consultation online.

Greenscape Geeks is a central Indiana landscape architecture and landscape design, construction, and lawn maintenance company, serving Indianapolis (including Meridian Kessler, Herron Morton, Williams Creek, and Irvington), Carmel, Noblesville, Fishers, and Zionsville.

This blog post is by Alicia Owen