The Bay-Friendly Landscape Guidelines recommend protecting all planting areas with a minimum of 3 inches of mulch.
California's Water Efficient Landscape Ordinance (WELO) now requires the use of compost and mulch on permitted landscapes. Find out more.
Mulch Best Practices
- Specify the finished grade to accommodate a 3-inch layer of mulch.
- Chip trees that will be removed from the site and use the chips on site as mulch.
- Use local recycled mulch produced from green waste.
- Keep root crowns free of mulch.
- Do not use landscape fabric under mulch.
- Use medium or light color mulch to avoid heat island effect.
- Specify a 3-inch layer of mulch wherever mulch depths are mentioned in construction documents.
- If sheet mulching is specified, include a sheet mulching detail in planting plans. See model sheet mulching specifications in Bay-Friendly Landscaping Guide to Mulch.
- Include notes on clearing and demolition plans and specifications if onsite trees are to be chipped for mulch.
- Integrate these practices into a soil management plan.
Calculating Mulch Quantities
Spread a 3-inch minimum layer of coarse mulch over the surface of all non-turf planting areas. Areas that will be planted with groundcover should also be spread with 3 inches of mulch. If the site is large, it’s good practice to keep a few small areas free of mulch to provide habitat for native bees.
To determine how much mulch you need, use our online mulch calculator or use this formula:
Total cubic yards of mulch = (A/27) x (B/12)
A = Total planting area in square feet to cover with mulch
B = Total inches of mulch required
1 cubic yard = 3 ft x 3 ft x 3 ft = 27 cubic feet
1 foot = 12 inches
- For information about using mulch in home gardens, visit our Gardening section.
- Local sources for compost, mulch and cardboard, and sample sheet mulching specification
- Bay-Friendly Landscaping Guide to Mulch: Save Money, Control Weeds and Create Healthy Landscapes
- Bay-Friendly Landscape Guidelines: Sustainable Practices for the Landscape Professional
- Washington State's Building Soil: Guidelines and Resources for Implementing Soil Quality & Depth BMP T5.13