Problems with Inorganic Mulches

Although inorganic mulches can be used to create attractive and low maintenance planting beds, they also can create a few problems.

Problems With Inorganic Mulch:

  • Large areas of inorganic mulch may increase soil temperature
  • Avoid black plastic – it does not allow water, nutrients or air to penetrate the soil
  • Inorganic mulches do not provide nutrients to plants
  • Rubber mulch may be harmful to plants

A Note on Weed Barrier or Landscape Fabrics:

Weed barrier fabric does not work well in areas where perennial weeds are a problem.

  • Perennial weeds will eventually grow through or over the top of the fabric
  • Reseeding perennials establish on the top of fabric making them very difficult to remove or transplant without damaging the roots
  • Organic matter (mulch) remains on top of the fabric and does not mix with the soil
  • Restricts ground nesting bee habitat

Additional Resources:


California – Landscape Mulch May Pose Fire Hazard

Washington – The Myth of Rubberized Landscapes


Missouri – Mulches (pros and cons)