Mulch 101

Ever since I started my landscaping business, I’ve noticed a lot of people don’t really know what to cover open soil with. You know the void between planting in the garden?

Naturally, nature will cover itself with other plants, what we might consider weeds, and debris —aka, fallen leaves, twigs, etc. While this can look great to some people, most urban homeowners lean towards thinking it looks unkempt. 

There are many things you can do. An option would be coving it with tree bark, wood chips rock mulch, ground cover plants, etc.  I want to focus this blog on the debate of whether to use rubber mulch or go for natural mulch. 

Natural mulch is anything I’d consider organic or naturally derived from the earth. This can include wood chips, wood bark, gravel or straw, etc.  Rubber mulch is manufactured out of recycled products like tires.  It is often dyed and come in chunks and when combined in mass they can be bouncy to step on. 

People who tend to like rubber mulch like it because it lasts a lot longer than most organic mulches. Therefore, the homeowner needs to replace it less often, saving in labor and new material costs. I could see using this for playgrounds or where a soft landing surface is beneficial. I, however, have not done any research at this point on the toxicity levels of it and if any undesirable substances transfer by regular light touch, like children playing on it. 

Lastly, rubber mulch works about the same as other more standard mulches in helping control weeds. The thicker, the better because it will help suppress weed seeds from getting set and thriving. 

We normally apply organic mulches like wood chips, wood bark, etc every season to every few years. It mostly depends on the biological level of the soil and the thickness originally applied. I encourage my clients to not use landscape fabric —unless using gravel— as it is ideal for the mulch to decompose. That way, the mulch adds nutrients and food to the soil. Naturally, that would increase soil health, regulates soil temperature, and helps hold in moisture.

While rubber mulch can do some of these things to an extent, it’s missing the big picture in my mind: soil health. Rubber mulch does decompose over time leaching chemicals into the soil. This can be harmful to your plants, the soil, and your groundwater.  In most circumstances, I recommend using natural mulch.

For example, for my parents’ yard, we ordered 10 yards from a tree service and spread ~6″ thick mulch all over. It has lasted 3-4 years and has really kept the weeds manageable. In small gardens, I often use a very fine chip blend —2-3″— and touch it up every year.

At the end of the day, I hope to be a resource for my client and help them make choices that make sense for their lifestyle. And if I can educate them on the products they use along the way, all the better. 

If there are other items you’d like to learn more about from a landscape perspective, let me know in the comments below!

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