The Pros and Cons of a Rubber Mulch Garden

Rubber mulch is a type of mulch made from recycled rubber, usually from used tires is used as a ground cover in landscaping and playgrounds as an alternative to traditional organic mulch, such as wood chips or bark. Rubber mulch is often favored for its durability, safety, and low maintenance requirements. The rubber is typically shredded into small pieces, colored to match the desired landscape, and then spread over the ground. The introduction of rubber mulch to the market has changed the way many people do landscaping and gardening. In the process it has created some polarization between those who think it is a good idea and those who don’t. People who are skeptical about its effects give reasons ranging from lack of organic “aesthetics” (look and feel), to fears about poisoning their plants with unseen chemicals. On the other hand, those who think that rubber mulch has specific benefits for gardening also offer good reasons (chief among them being the reduction of carbon footprint).

Let’s take a closer look at both the benefits and disadvantages of using rubber mulch for your plants.

The Pros:

It provides good insulation from heat. Rubber mulch does a better job of insulating plants from heat compared to wood chips and other organic materials. In “indoor” gardens like sun-rooms and solariums, it is especially beneficial because it does not break down and emit a rotting smell.    

It won’t attract insects. Unlike soil and wood, rubber isn’t attractive for insects to build nests in or gnaw on. This is particularly true for ants and termites. Some even use rubber mulch as a sort of insulation around their homes to keep insects at bay.

It discourages weed and fungal growth. Because rubber does not absorb water, rubber mulch can actually help prevent fungal growth in plants. The shredded rubber tire “nuggets” are non-porous so water and fertilizer passes through it down to the soil it rests on. Weeds cannot thrive on the rubber and can’t get through the mulch layer down to the soil.

It lasts forever.  Well maybe not forever, but since rubber is very slow deteriorate, you can expect to enjoy the landscaping material for many many years without the cost and hassle of topping it up annually.

It stays in Place.  Since rubber mulch is heavier than organic mulches (and water) it doesn’t displace easy and won’t float off during heavy rainfall.

It provides more design options.  Available in many earth tone and designer colors, rubber mulch offers more options to compliment existing landscape elements.  Unlike colored wood mulch, rubber mulch tends to hold its color for up to ten years.

It is a low maintenance option.  When compared to organic mulches, the density and durability of rubber mulch translates into less maintenance and replenishment costs saving both time and money.

It provides twice the coverage.  While Rubber mulch is initially more expensive it requires only a 1.5 inch depth to effectively control weed growth compared to 3 inches of organic material.

It’s an environmentally friendly option.  Rubber landscaping mulch is made from recycled tires. Using this material not only helps to prevent landfilling but also also requires no tree sacrifices.

Safety: Kids will be kids, and scrapes, falls, and accidents will happen especially when they are playing outdoors. Whether at home or elsewhere, ultimately, your child’s safety is what counts. What rubber mulch can do is to provide extra springiness for when kids fall or stumble while at play. With proper installation and adequate depth (around six inches), a rubber mulch surface will give up to 16 feet of critical fall height protection compared to gravel or wood mulch. It can cushion many mishaps and help your child avoid fractures, brain trauma, and other playground-related injuries.

EPA-endorsed: The Environmental Protection Agency (EPA) has actually endorsed the use of rubber mulch for playground surfaces. The agency has also done surface and atmospheric tests on playgrounds using rubber mulch, and found no significant adverse human or environmental effects. And due to the process of recycling and repurposing rubber mulch undergoes, some states like Kentucky have incentivized its use. Even the playground at the White House uses rubber mulch.

Skin sensitization-tested: Because they are made of recycled tires, children with sensitivity to latex and rubber may be at risk when exposed to rubber mulch. However, the California health hazard branch of the EPA also tested rubber mulch for skin sensitization and discovered that it does not elicit skin reaction among kids, even with those who have a predisposed sensitivity towards latex.

The Cons:

It does not decompose. Rubber mulch is not organic, so it does not decompose and will not provide the soil with organic material.

It contains chemical residues which can be harmful to plants. Contrary to popular belief both wood mulch and rubber mulch can contain chemicals.  Some wood mulches are made with industrial pallets that may have come in contact with various chemicals.  Rubber of course utilizes chemicals in the manufacturing process. Studies differ as do mulches themselves. The most common chemical in rubber mulch that is found to potentially affect soil is zinc. Zinc is found naturally in soil and too much or too little can affect soil quality. Some areas of the US have sufficient or even high levels of zinc in the native soil whereas other areas have a zinc deficiency.  If you are uncertain you may wish to test your soil for zinc levels before making a decision on what product is the best fit for your landscaping project.

It doesn’t look and feel organic. Despite the many natural colors available some prefer the natural look and feel like real soil, wood, or stone.

Heat: Rubber mulch can become hot in direct sunlight, making it a little uncomfortable for pets and children to walk or play on.

Pros and Cons of Rubber Mulch for Schools:

Preschool playgrounds require adult supervision, age-appropriate play equipment, and sufficient ground coverage for active children. Rubber mulch has been proven time and again to have the best shock absorption when it comes to falls from certain heights. It also doesn’t retain moisture so kids won’t slip or slide while running on it. Rubber mulch doesn’t need to be replaced annually because it requires very little maintenance and won’t degrade as fast as organic mulches. However, having a stock of rubber mulch on hand could add a layer of creativity and fun for playground activities. You can create geometric patterns like a checkerboard so kids can play life-size chess or checkers, or design whimsical patterns like waves in an ocean or flowers in a field to ignite kids’ imagination.    

Pros and Cons of Rubber Mulch for Businesses:

For many businesses, first impressions contribute to sealing the deal. In these times of climate change and the inevitable drought/flooding that goes with it, maintaining a manicured front lawn doesn’t really make a great first impression. It requires upkeep and maintenance, plus plenty of water that could be conserved for better use. Using bulk rubber mulch for corporate landscaping is a more practical option. It doesn’t require that much maintenance, it won’t degrade in extreme weather conditions, and it is the product of recycling - a concept and lifestyle adapted by the most conscientious businesses. Companies can opt to spell out their company name or integrate their logo using colored rubber mulch, and it will serve as a great advertising for what the people behind it stand for.

Pros and Cons of Rubber Mulch for Parks:   

Public playgrounds make up a big part of a Parks and Rec department’s responsibility and jurisdiction. This means play areas, parks, landscaping for rest and recreational areas, etc. Since rubber mulch as playground surface has a high safety rating as far as impact and shock absorption go, it only makes sense to use it on public playgrounds. Admittedly, they cost more initially compared to other mulches, so buying in bulk is a practical move. And when playground rubber mulch needs to be replaced, they can be repurposed into landscaping or horse arena ground cover.  

The important thing is to do research prior to purchasing. Weighing the pros and cons carefully is key to deciding what’s best for your particular landscaping and garden projects.

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