Action of the Month: DIY Sheet Mulching
Fall is the perfect time to sheet-mulch. Not familiar with that term? It's a layered mulch system that nurtures the soil and replaces existing lawns or weeds, eliminating the need to remove unwanted plant material (no harsh herbicides, no roto-tilling!).
A SCOCO board member just sheet-mulched her front yard in Concord last month - here's how you can too!
1. Apply for a lawn conversion rebate BEFORE you start, if you are removing a lawn and planning to replace it with drought-tolerant landscaping (such as low-water or native plants). The water district will come out to measure your lawn and confirm that you qualitfy. You may want to check if you qualify for both your local rebate and the State Rebate; you could potentially get up to $2 per square foot that you convert! Then, stop watering your lawn and let it die. Before your sheet-mulching weekend, water the ground thoroughly.
3. Dig a trench around all edges of your lawn, including edges butting up against your driveway or other hardscapes. Dig at least 2 inches deep and up to a foot wide - this will create a low point along the pavement so the mulch will not spill out. You can put the dirt you dig up onto the other parts of your lawn, to incorporate the nutrients back into the earth.
2. Find and cap all of your sprinklers. Dig around each sprinkler head, going 3 - 5 inches deep until you are below the connection point. Unscrew the sprinkler head and screw on a cap - I used simple PVC caps from the hardware store. Some sprinkler heads required a special tool to remove pieces if they broke and got stuck. You may want to also put a flag by each sprinkler head so you can find it again after you mulch (ex. if you are converting to a drip irrigation system).
4. Apply a thin layer of compost (~1 inch) over the dead lawn or weeded area. You can order compost and mulch from many local facilities, and most offer delivery services.
5. Layer flat sheets of cardboard over the area, making sure to overlap the sheets by 2 inches to make sure no light can penetrate through to the grass or weeds below. I used large cardboard boxes from friends who had just moved, as well as flat pieces of cardboard I got from Costco (make sure you ask first!). Remove any tape that may be on the boxes (tape won't decompose). Helpful hint - you will need more cardboard than you think. I made 2 additional trips to get more cardboard even after I thought I had enough!
6. Water the cardboard. Wave to your neighbors as they pass by, wondering if you've gone crazy.
7. Spread ~3 inches of mulch on top of the wet cardboard.
8. Sit back, relax, and let the sheet mulch "cook" for a month (or more) before planting! This will allow everything to settle, and the cardboard (which acts as a weed-blocker) and dead grass/weeds will slowly decompose into the ground. If you plan soon after, you'll just need to cut holes in the cardboard where your plants will go in.
This particular front yard conversion project will be incorporating some pollinator-friendly and drougt-tolerant plants as well as two trees in the next month or so. Check if your water agency provides a landscape design assistance program so you can utilize a professional designer to help transform your yard from water-thirsty and boring, to drought-tolerant and beautiful.
Learn more about local rebate programs:
Contra Costa Water District - Lawn to Garden Rebate Program
East Bay MUD - Landscape Rebate Program
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