Synthetic Mulches

Every gardener out there is looking for the perfect solution to the problem of garden weeds, maintaining soil moisture and providing some aesthetics to their gardens plots.  Many gardeners over the years including myself have turned to garden mulches in order to fill that need.  But with the plethora of choices out there it is hard to decide which direction to go.  The first choice anyone that wishes to use mulches must make would be whether to go with synthetic/artificial mulches or to go with natural mulches.  This decision has forced me to do some research into what exactly are artificial mulches, what are they made out of, and what sort of chemicals or toxin could be present in the various mulch types. 

Some types that I have come across in my research include rubber tires, plastic sheeting and landscaping glass.  And with the exception of plastic sheeting are all recycled from other products that can no longer be used for their intended purpose. 


Rubber Tires

The first I am going to cover will be the recycled rubber/tires.  This particular mulch depending on who you ask would either be a divine gift to gardeners and school children or it could be the next Love Canal.  It has many pros and cons that have be partially summed up in Table 1


Rubber MulchCredit: Phasmatisnox at English Wikipedia




Table 1



       -Doesn’t float away

       -Prevents Erosion

       -Allows water and nutrient infiltration in             the soil

       -Does not integrate into soil

       -Provides effective weed barrier

       -Doesn’t provide a medium for wee growth

       -Non Toxic and for all intents permanent            (no reapplication)




       -Releases lead into soil

       -Releases toxins

       -Releases minerals such as aluminum,                 cadmium, sulfur and zinc into the soil                 beneath mulch

       -Can catch fire and be difficult to put out

       -Injury risk due to metal pieces in                         shredded tires.


My Take on Rubber/Tire Mulch

While the benefits to using shredded rubber in both landscaping and vegetable gardening are obvious I feel for me at least there is not enough data our there from independent sources that back up the industry claims.  I personally feel that any potential toxin or minerals leaching into my soil on which I grow my food is too much.  Even though EPA studies have found the leaching of lead and zinc and other toxins and minerals to below acceptable limits this would still not be a preferred choice for me. 


Landscaping Glass

Moving on to landscaping glass an up and coming landscaping tool using glass beads or aggregates of various colors to provide a visually interesting and effective landscaping tool.  This particular landscaping mulch has many pro's and few con's that my research could dig up.  Some pros would include aesthetically pleasing, effective as a weed barrier, long-lasting and is a 100% recycled material.  Some cons would be that once applied it is difficult to completely remove and doesn’t amend the soil at all.

My Take on Landscaping Glass

I could see myself using this material very specifically, such as in walkways or around fire pits basically any area where I can no intention of trying to grow plants.  But I would prefer not to use it anywhere I was planning on growing vegetables fruits or even just ornamental.  The main reasons for this are the cons mentioned above, I don’t like that it would be difficult to move and shift once applied and that it doesn’t contribute to the soil beneath it.


Plastic Mulches

Finally I looked into plastic mulches, which for any of you who have also done research on this know it is a very broad topic.  For the purpose of this article I am going to include all of them under the umbrella of plastic.  For plastics some of the pros and cons I dug up  are,


      -Completely smothers weeds

      -Easy to apply to large areas

      -Relatively cheap due to mass production

      -Can last for many years depending on type



      -Depending on type doesn’t allow                           infiltration   of nutrients and water.

      -Can cause erosion on edges of mulch

       -Doesn’t amend the soil at all

       -Can contain potentially harmful chemicals

       -Can transport pesticides and herbicides to          unintended locations


My Take on Plastic Mulches

I like them for their cheapness, their ease to apply to large areas, and that they can completely smother weeds.  But I cannot ignore the cons of the plastic mulches either.  Similar to the glass and rubber I mentioned above they do not amend to soil, which for me since I mainly vegetable garden is a necessity, I need to amend my soil with nutrients and organic matter in order to keep up production levels.  In addition I find these plastic mulches an eyesore and I wouldn’t want them as part of my vegetable operation.  I could see myself using it for weed control in windbreak plantings or even in individual tree plantings.  I would also consider using them as a site prep tool for preparing a new garden plot, either for no till planting the following year or after fall tillage in order to control the fall and spring flush of weeds.

 I hope that my compilation of the pros and cons of synthetic/artificial mulches will aid you in deciding what you will use in your garden this year and in the years to come. 

 Thank you for your time and I look forward to any comments you would like to make on the article and any suggestion you would have for adding to it in the future.