Sheet Mulching

Transform your Lawn Without even Digging

by Elizabeth Leboe
Gardens West Magazine Article, 2009

Let’s start by considering why we have lawn. Originally, the conversion of arable land into non-productive grass symbolized wealth. Landowners didn’t need to grow food. Instead they hired workers to tend their pretty lawns. Today, grass tracts are a testimony to the triumph of humans over nature, the “brand” of urban and suburban living. They are still a sign of wealth and leisure.

Wait a Minute – Leisure?!

The kings and queens of yore may have had armies of minions tending their lawns, but you probably don’t. You weed it, you feed it, you water it, then you mow it, you rake it, you get rid of the “harvest”... and then you must do it all over again. What has your lawn done for YOU lately?

If you feel like your lawn is taking up a lot of your energy and not giving you back enough, maybe it is time to consider converting part of it into something a little more beautiful and much more productive. I’ll bet your lawn is occupying the sunniest, flattest spot in your yard.That sounds like a location that will be perfectly suited to a new flowerbed or, even better, a veggie plot.

Turn Your Lawn Into Garden

I can hear you saying, “But I don’t have the energy to dig up that lawn. Isn’t there an easier way?”

Yes, there is! Not only is removing turf hard on your back, but doing so also removes the healthy topsoil that is needed to nurture your new plants.

The good news is that by imitating Mother Nature, you are well on your way to a new garden without ever having to dig up the sod.

“Sheet mulching” imitates ecology by layering organic materials on an area of lawn, weeds or poor soil to create rich healthy soil for your plants. Mother Nature never rototills anything. Why should you?

So put away your spade and gasoline-powered machines and begin hoarding organic materials. When the time is right, gather together some helping hands to make the job faster and more fun.

Site Selection

Pick a site that suits your new garden’s needs. The existing soil does not have to be good. The patch of weedy lawn we selected is ideal for flowers and vegetables. It is south-facing and backed by the wall of a house.

Gather Materials

Collect some of these materials for your sheet mulch project. Be creative, many materials are considered “garbage” and are free!

Weed Barrier Materials

• Burlap, wool or cotton fabrics or natural-fi bre carpets
• Newspapers or cardboard

Soil-Building Materials

• Grass clippings, soft plant prunings or weeds (dry weeds in the sun or drown in water to kill them)
• Fallen leaves
• Straw
• Thin woody prunings
• Manure
• Used stable bedding
• Peat moss
• Compost

Prepare Your Site

Mow or trample the grass and weeds and leave them there. If you have any organic fertilizers (rock dust, alfalfa meal and such) scatter it on your new garden site. Water the site well.

Weed & Grass Barrier

This is the most important part of the sheet mulch project, as this step replaces digging up sod. These are the basic rules for whatever barrier material you use:

• Overlap edges well (15 cm or 6" or more)
• Don’t skimp (if you can poke through it, so can weeds and grass)
• Don’t leave gaps

Ideally, you would lay down a thick, unbroken barrier and let it naturally break down while it smothers the weeds and grass below. But in spring, you likely have rooted plants to place in your new garden; in this case, lay the barrier material snugly around transplanted perennials.

Layer Soil-Building Materials

Mix and match as many different kinds of materials as you can get your hands on. Don’t be stingy – make an “organic sandwich” at least 4" (10cm) deep as it will shrink by ¾ as it composts down.

Planting is Optional

Large seeds work best in a new sheet mulch (potatoes, garlic, squash). Rooted plants should be planted into the soil below the barrier layer – either cut an “X” through the barrier and plant through it or place the plant first, and lay the barrier material around its stem.

A Finished Garden

Water heavily to kick-start the composting process. A optional layer of topsoil will make the garden look finished. As the season progresses, organic materials will compost down and turn into beautiful, rich soil. You can add more mulch materials to the top as you gather them.

Conclusion

Sheet mulching is an easy way to convert lawn into garden. Best of all, the technique is flexible enough to work with whatever materials and energy you have available and you can do it at any time of the year.

You can also use this method to improve soil on existing garden beds. So transform your lawn. Pile it on!