Is rubber mulch safe for gardens?
Date Modified: 10/22/2009 1:06 PM
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Rubber mulch is a fairly new product. Is rubber mulch safe for my garden in the long run?
Rubber mulches are advertised as permanent, effective and safe materials. At first glance, it may seem that rubber mulches are an environmentally friendly way of recycling used tires. Additional research indicates they are neither effective in long-term weed control nor safe for the environment. While recycling waste tires is an important environmental issue, the solution isn't to spread pollution over our landscapes and gardens.
Rubber mulch is made from recycled tires. It takes approximately 80 old tires to create one square foot of rubber mulching. It reduces the waste that gets shipped off to your local landfill. The problem arises when the tiny wires in radial tires get mixed in with mulch. These wires eventually rust out in a couple months and this causes concerns as to what chemicals are being leached into the ground. Wire-free mulching is available for an extra cost. This mulching is required for playground installation for obvious reasons.
Rubber mulch is most common for playgrounds. Its superior shock absorption rating outperforms wood mulch, gravel, and sand. Wire-free, rubber mulch is the safest playground material available. While rubber mulch costs about twice as much as traditional mulch, it lasts considerably longer. High-end rubber mulch can last for the lifetime of your home. Rubber mulching can also be a great choice for horse arenas and general landscaping.
The topic gets a little trickier when talking about using rubber mulch in gardens. There's a good chance that over time your rubber mulch will leak chemicals into your soil. What chemicals and how much can depend on several factors, but the most common is zinc. Zinc is found naturally in soil, and too much or too little will affect the quality of topsoil. Test the soil if you're considering rubber mulch.
One of the advantages of putting rubber mulching in your garden is that it doesn't attract termites or carpenter ants and won't wash away in a rainstorm. On the other hand, if your garden is full of delicate plants that require ideal conditions to grow, you might consider sticking with the wood mulch.
It's recycled material, which benefits the environment. It insulates the soil protecting it from heat and doesn't absorb water so it keeps the soil moist. It prevents weeds since seeds will dehydrate in the mulch. Shredded rubber mulch doesn't wash away during heavy rain and doesn't decay. It doesn't attract termites, ants and other garden insects.
Tires and rubber mulches are eventually broken down by environmental factors. Chemicals that leach from tires are anything but benign. They include heavy metals, such as aluminum, cadmium, chromium, molybdenum, selenium, and zinc.
Acidic soils are particularly sensitive because heavy metals are more available for plant uptake. Decomposing rubber mulches provide a constant stream of toxic leachates into adjacent aquatic systems.
Keep those questions coming by sending to Christine Schlueter, 19276 Walden Ave, Hutchinson MN 55350 or e-mail rcschlueter@yahoo.com