California Department of Transportation
 

Native Grass Sod

Native Grass Sod

What is This Treatment?

This work involves placement of commercially grown sodded grass that is composed of a mixture of drought-tolerant native California grass species.

When to Use This Treatment?

  • Wherever immediate 100 percent cover of disturbed soil areas is required.
  • Biofiltration strips and Biofiltration Swales.

Benefits:

  • Provides immediate soil cover, providing immediate control of surface erosion.
  • Montana State University research data showed that a freshly tilled 2.5:1 (H:V) slope treated with hydroseed yielded 1-2 tons/hectare/year while the native grass sod yielded only 0.6 tons/hectare/year.
  • Immediate cover greatly reduces competition from invasive weed species.
  • Low long-term maintenance and establishment costs due to the ability of sod to reduce weed emergence and survival.
  • Controlling erosion at the source is much more cost effective than trying to remove sediment or metals from stormwater runoff downstream.
  • Sod strips placed at the toe of the slope remove soil particles from surface runoff before it leaves the project site.

Limitations:

  • High initial cost. Materials cost is expected to decrease as the supply increases.
  • May require supplemental irrigation.

Technical Design Tips:

  • Amend soil with compost and/or slow-release organic fertilizer
  • Pre-germinate and kill weeds if possible.
  • Install just prior to the rainy season if possible.
  • Supplemental irrigation may influence dominance of certain native grasses over others.
  • Supplemental irrigation may increase competition from adjacent invasive annual weeds.
  • Recommended grass specie mixes vary by ecoregion. The best mixes develop a strong, contiguous root mat, easing harvest as well as precluding propagation of weedy species from the underlying soil seed bank.
  • Verify availability (geographic location and sod mix species) before specifying this product.

Consider Using With:

To effectively treat sites with poor soils (compacted, nutrient poor, or poorly draining), consider combining this treatment with:

Specifications:

Plans and Details:

  • No Standard Plans or details required.

Estimate Information:

  • $1.00 - $4.00 per square foot (2010) for quantities of 10,000 - 30,000 square feet.
  • $2.25 per square foot (2010) weighted average for quantities between 10,000 - 30,000 square feet.

References:

Caltrans Native Grass Sod Webinar

2008 Montana State University Research Report. Using Reinforced Native Grass Sod for Biostrips, Bioswales, and Sediment Control.

Updated 10-08-2013