Have you been interested in transforming your lifeless, ever thirsty lawn into a more vibrant and water-wise garden, but don’t know how to even start the lawn removal process? Sheet mulching is an excellent solution and is a method of ‘composting’ your old lawn in place using cardboard and wood chips. This lawn ‘removal’ method has numerous advantages, including that it’s much less labor intensive than physically removing the lawn, it causes minimal soil disturbance, adds nutrients to the soil and encourages soil life forms (ie. worms and microbes) to return. Below sheet mulching is laid out in 5 steps.
Procure plants, supplies and tools: Sheet mulching supplies include cardboard, 6'' heavy duty landscape staples, a box cutter, a rubber mallet, and a shovel. For lawn conversions under 500 SQFT, consider asking a local appliance store about collecting their pile of large cardboard boxes headed for recycling. For projects over 500 SQFT, the most efficient option is to purchase rolls of corrugated cardboard (3’ x 50’) from hardware or office supply stores.
Prepare the land: Complete all underground irrigation piping alterations or additions. Mow the lawn and water thoroughly. Trench around the lawn area that will be sheet mulched. The trenches should slope gently down towards the surrounding hardscape surfaces, no more than 2 feet wide and 4 inches deep. This will allow you to tuck the cardboard down around the edges and help keep the mulch from spilling out onto the sidewalks over time. Use the excavated soil to create a couple mounds in the yard for added visual interest.
Lay Cardboard: Cover the entire area with 1-2 layers of cardboard. Overlap each edge by 6-8 inches, so that no light will get through to the soil, so as to discourage the regrowth of grass and weeds. Water as you go to help keep the cardboard flat and from blowing away. Use sturdy 6'' landscape staples to ensure the cardboard remains flat and in place over time.
Plant: Set out plants in your desired arrangement in the yard. Use a box cutter to cut through the cardboard, dig plant holes and plant. If you're planning to install drip irrigation lines to each plant, this is the time to do it. The drip lines run above ground, but underneath the mulch.
Mulch: Apply 3-4’’ of chemical-free wood chip mulch over the entire surface, so the cardboard is completely hidden. Chips can be obtained free or low cost from a local tree trimmer or purchased and delivered from a landscape supply yard. Avoid using Pine, Walnut, Eucalyptus, or Live Oak. Remember to leave a few inches around the stem or trunk of each plant free of mulch to avoid stem rot.
The rainy season has arrived and it is the best time to sheet mulch because the decomposition process is aided by moisture. Native plants also do best when planted in autumn so they have time to set roots before the heat of the next summer. Contact Earth & Spirit for consultation and coaching with your project and for a design for your new native garden!