Native Grass Sod Suitability for Transportation and Competition with Resident Weeds

Sod mixes for the California ecoregions of Pacific Forest, Sierran Forest, and Intermountain Sagebrush were grown at two different planting densities (500 and 1000 pure live seed per square foot) in 4’ x 5’ plots.  High density sod, produced over eight months had significantly higher sod strength than the lower density sown sod.  At harvest, both densities of sod were transported onto prepared soil beds with and without reinforcement mats.  Known quantities of weed seeds were mixed in the top 2 centimeters of the soil beds.  All sod rapidly established on the growing medium, regardless of density or reinforcement mat.  Both the mat and high initial planting density sod suppressed weeds.  The initial planting density and presence or absence of reinforcement materials affected the resulting species composition.  All species transferred successfully, but Bromus and Festuca predominated with <5% comprising the remaining species in the mixes.  The higher sowing densities proved more successful, suggesting that they are necessary for transport of native grass species mixes sod.  Reinforcement mats aided in sod transport coherence and did not hinder establishment of the sod.