Sustainable Contra Costa Action Guide

Transform Your Thirsty Lawn into a Water-Sipping Landscape – the easier way

By Jillian Steinberger

The Garden Artisan

More than once, I’ve been called out to look at a client’s yard when they’re ready to convert their lawn to a drought tolerant landscape. More than once, they’ve called me after the lawn’s been dug up. When this happens I think, “Sheesh, too bad!” Why? Because the client paid for the labor – or did it themselves on their day off. Then they paid to have the green waste hauled away, which can cost hundreds of dollars. So, I say: Save your back, save your *biomass, and save your money! Become a true believer: Sheet mulching really works. I have the pictures to prove it.

So, what is sheet mulching? It’s a natural, non-toxic way to kill grass while improving soil, any time of the year. Basically, you cover up your old lawn with cardboard, compost and/or mulch. The grass breaks down under the cardboard (worms love it), composting in place and raising soil bioactivity. Win-win.

So, how do you sheet mulch? Here are the steps:

1. If the lawn is high, mow it. Then dig a trench around the edges, and dig planting holes if you are planting soon. Measure the square footage of your lawn; this will help you figure out how much cardboard, compost and mulch to get.

2. Now put the cardboard on the lawn and also line the trenches and planting holes. Completely shut out sunlight from reaching the grass by overlapping. Use 2-6 layers, depending on the level of weediness. I recommend cardboard rolls, available from Monahan Paper in Oakland (510-835-4670, no website), a 100-year-old family business. They deliver to Contra Costa for free. (The thickness is half of regular cardboard, so double up if you’re using rolls.) You can also track down bicycle or refrigerator boxes for free. Newspaper works well, but you have to use a lot so start saving now! (Tip: Don’t use landscape fabric, which is not meant to break down.)

3. Next comes compost or planting mix and mulch. If you are not planting for several months, put 2” or more compost under the cardboard. If you are planting soon, the compost can go on top. Then follow up with 3-8” of mulch – the thicker the better. Leaves make beautiful mulch, and they’re free. So, don’t send those leaves to the landfill! When purchasing, I like EcoMulch, a family business in Martinez (www.myecomulch.com). Their mulch is made from urban trees. The price is right, it has an attractive, uniform look, and it’s not weedy. For those who like a black or red mulch, they even offer colored mulches made with non-toxic vegetable dyes. When budget is tight, I put mulch right on top of the cardboard. (Tip: Don’t use “Gorilla Hair” mulch, which traps water and keeps it from draining into the soil.)

4. So what next? Some people walk away for a year and let nature take its course. When they return, they usually find that the grass and cardboard have broken down and the soil is beautiful. However, most of us want to look at plants, not mulch! If that sounds like you, then before putting down the mulch add planting mix to holes. Then plant, and finish off with mulch. Et voila! You can also sheet compost, and plant a meadow right on top of a lawn!

You may already have witnessed the domino effect going on in some neighborhoods: One brave neighbor installs a mulched landscape with Mediterranean or native plants. They’re the first on the street. Another likes the look and follows suit. Then another. Meanwhile, some of the neighbors shake their heads and scratch their chins. Isn’t mowing what gardening is all about, they ask? But sooner or later the look grows on them (maybe it’s when the ceanothus blooms), and they start hearing more birdsong... And the cardboard rolls again!

*Keeping your green waste (like a lawn you no longer want) onsite builds up biomass. What this means is, as green waste degrades it builds up organic matter in the soil on your property. This invites beneficial microorganisms, which further enliven the soil. This is the opposite of erosion. Organic matter is the earth’s skin! Let’s keep Gaia looking beautiful, naturally.

Jillian owns and operates The Garden Artisan an ecological landscaping company which designs and builds beautiful yet sensible landscapes that are appropriate for Northern California gardens. She focuses on native, edible and pollinator plants, and loves the challenge of sheet mulching over bermudagrass! Contact her at jillian@garden-artisan.com.   

Watch Kat Weiss show you step by step how to convert your lawn the Bay Friendly Way