Master Gardener Garden Education Center
Bermudagrass Mitigation Project
The Gardening Education Center (GEC) at the San Mateo County Event Center is now a UC Master Gardener “experiment” for Bermudagrass control by increasing the diversity of the microbial community and building biological soil structure
The soil at the GEC was mulched using 1 layer of cardboard and 3+” of arbor mulch to kill the sod. The sod was killed but the Bermudagrass was not killed. The soil was too compacted to pull the Bermudagrass out. After extensive research a plan was adopted to treat the soil with compost extract, compost and a diversity of cool season cover crops to grow over winter: Windsor fava beans, crimson clover, berseem clover, Austrian winter peas, common vetch, lupine, daikon radish and phacelia. These seeds were chosen for their ability to outcompete weeds, open compacted soil and add organic matter to the soil. The cover crops were chosen from the California Cover Crop Chart prepared by the Natural Resources Conservation Services (NRCS).
https://www.nrcs.usda.gov/Internet/FSE_PLANTMATERIALS/publications/capmctn13333.pdf
After the land was cleared of mulch, all visible Bermudagrass, and graded, the seeds were planted in October 2018. Using small batch microbial diverse compost donated by former county Master Composter Instructor Alane Weber a compost extract was made and applied over the seeds to introduce microbial life into the soil including beneficial bacteria, fungi, protozoa and nematodes. The seeds were then covered with a modified green waste compost. Within days the seeds started germinating and the GEC is now a blanket of green.
In spring 2019 before the cover crops produce mature seeds the plants will be cut down and left as mulch and the roots will be left in place. The roots will provide food for the microbes including the fungi. A spring/summer cover crop will be planted and in the fall it too will be cut down and left in place.
In fall 2019 another cool season cover crop mix will be planted in the hope that by spring 2020 the goal of building biological soil structure with the cover crops, compost and compost extract will be realized. We anticipate some of the Bermudagrass rhizomes and seeds will be weakened and decomposed by the fungi. The Bermudagrass that does survive should be much reduced in number and vigor and easily pulled out due to the more open soil structure created by the microbial life, the cover crops, and the earthworms.
To follow the progress on the Bermudagrass Mitigation Experiment please visit our website. https://ucanr.edu/sites/MGsSMSF/