Gardener’s Notebook

To Transform Your Yard, Start from the Ground Up

Do you enjoy spending hours of your precious spare time mowing a lawn and pulling weeds just to have a fussy green rug around your house? What if instead you could have a lush garden full of beautiful and useful plants for the same amount of effort? This article begins a series in how to achieve a total yard transformation. I’m including instructions that will help you carry it out on your own, should you choose to get your hands in the dirt.

Life of the Soil

Let’s start from a basic premise that the soil underfoot should be very much alive. The microbes that convert latent nutrients into accessible nutrition for your plants are working night and day below the surface. What if there was an easy way to foster that microbial growth? In fact, there is! It’s called sheet mulching. The benefits to your soil and plants include a lengthened wet period of the soil, reduced weed penetration, and a steadier release of nutrients. 

If the soil under your lawn has been neglected, this is your opportunity to improve it. To find out what your soil may need, you can invest in a soil test. For around $70 you can get a thorough lab analysis. Plus, a soil test can tell you whether the soil is safe for food production. I recommend Wallace Labs.

After you remove the grass and its roots, but before you begin sheet mulching, you would do well to broadcast inoculants and soil conditioners. I like the Down to Earth product Bio-Live, which is laden with endomycorrhizae and trace minerals. When wetted under the sheet mulch, it will begin to foster microbial life immediately. These amendments will “farm” the soil to create optimal nutrient availability to the plant roots. I also like to add a light broadcast of bone meal, kelp meal, and volcanic rock ash, depending on soil needs. If you wish to stay “in-house” with your amendments, simply spread one inch of your homemade “finished” compost under your sheet mulch.

Cardboard Layer: A Skin for the Earth

Sheet mulching can be done a number of ways. If you want to do it yourself in a small area, you can collect large cardboard boxes from bike shops and appliance stores. Simply break them down flat and stake them into the ground on all corners, making sure you overlap the edges, since those seams are where weeds will attempt to sprout.

It is important to put in your new plants soon after sheet mulching, as the cardboard may tear if moistened without the protective cover of mulch. To plant, first cut large circles in the cardboard with a box cutter, then dig your hole. If you are adding soil, try Joshua’s Soil Blend:  ~50{94d79dd6af1e87a94e700e4c297236468333f22e27ed5757b44711974a9a4b91} native soil, ~40 {94d79dd6af1e87a94e700e4c297236468333f22e27ed5757b44711974a9a4b91} planting mix, 5{94d79dd6af1e87a94e700e4c297236468333f22e27ed5757b44711974a9a4b91} compost, and 5{94d79dd6af1e87a94e700e4c297236468333f22e27ed5757b44711974a9a4b91} worm castings.

For large areas, commercial cardboard rolls might be easier. This post-consumer product can be rolled out like carpet and tacked down with ½-inch irrigation stakes.

Mulch to Drought-Proof your Garden

Once your plants are in the ground, follow up with wood chip mulch. I recommend 3 to 4 inches of mulch, making sure to not bury the root crown of each plant, as this can lead to rot and disease. The mulch will act as a sealant for moisture entering the rhizosphere (root zone). For shorter-lived annuals, I recommend mulching with coconut coir, an organic matter made up of small particles that break down much faster than wood chips. Where my broccoli grows, for example, the coir mulch shields the roots from the hot sun. After I am finished harvesting my broccoli, I turn this coir mulch into the soil. This helps build soil tilth, as the coconut fiber is fluffy and quickly becomes colonized
with microbes.

How to Mulch and Support Native Bees

Since the sheet mulch will drastically reduce weed sprouting, I recommend doing something good for native bees by raking out 1-meter circles and leaving them bare for ground-nesting species. Into these circles I seed wildflower mixes such as California poppy (Eschscholzia californica), lupine (Lupinus albifrons), and yarrow (Achillea millefolium), which will offer pollen to bees. For more information on ground nesting bee habitat, check out this website: https://www.xerces.org/enhancing-habitat-for-native-bees/. 

With sheet mulching, you do more of the hard work up front to create ideal conditions for soil health and water efficiency. While this makes the start-up more arduous, you can rest assured that the payoff will be rewarding as you go forward with planting and harvesting your food crops.

Photos: Joshua Burman Thayer

Joshua Burman Thayer is a San Francisco Bay Area ecological and permaculture landscape designer and consultant specializing in dry-land landscape design. He can be reached at 510.332.2809, www.nativesungardens.com