Here’s how to create a lasagna bed, also called sheet mulching:

• Start in fall so the bed has all winter to start decomposing.
• Cut grass as low as possible. Or start a lasagna garden on top of an old planting bed.
• Loosen soil with a digging fork to increase aeration. Even punching holes in the ground will work.
• Remove weeds.
• Build a raised bed frame or just mound up the layers of organic material into an unframed bed.
• Put a layer of cardboard overlapped an inch or two and water it.
• Cover with 2-inch layers of green organic material like grass clippings, fresh plant debris, fresh animal manure and food scraps that provide nitrogen and brown materials like dry leaves, wood chips, straw and shredded newspaper that are carbon sources. Repeat layers until the bed is about 18 inches.
• Top off with a 2- to 6-inch brown layer; thicker if you want to plant right away.
• Create beds only wide enough to reach into the middle and create paths lined with straw to walk on so soil doesn’t get compacted.
• Lasagna beds will shrink as materials decompose and may need refreshed layers each year.
• Using transplants is easier in no-till gardening systems; the mulch layer is easier to transplant directly into rather than direct seeding, especially for small-seeded crops like lettuce and broccoli. To transplant, use a trowel or other tool to make holes large enough to plant into. If directly seeding into the bed, pull back the mulch layer and smooth over the surface layer with a rake before seeding.

Instructions from OSU Extension website https://extension.oregonstate.edu/news/no-till-garden

The term “Lasagna Gardening” was coined by Patricia Lanza, who wrote a book on the subject in 1998. The illustration above is from her book.