Lasagna gardening: Layers and layers of goodness

JACKSON, Mo. — As traditional gardening season takes a bow, lasagna gardening makes a grand entrance.

Lasagna gardening is no-till, no-dig gardening that uses materials typically thrown away such as kitchen and yard waste, says University of Missouri Extension horticulturist Donna Aufdenberg.

Aufdenberg says lasagna gardening is environmentally friendly and frees the gardener from tilling, weeding and digging. Gardens also retain moisture well.

Fall is the perfect time to build a low-cost, nutrient-rich lasagna garden, she says. Use ingredients such as grass clippings, leaves and small tree limbs, which are readily available for free from friends, neighbors and city cleanups. Stockpile ingredients throughout the year to build new beds or maintain existing ones.

Lasagna gardening requires no special tools or materials. Gardeners can build a frame for their gardens or go without. Aufdenberg recommends cypress, cedar or other untreated lumber that does not leach contaminants into the soil. She discourages metal or plastic frames that can heat up to dangerous levels.

Choose a level site that offers full sun. Avoid areas with large trees. Prepare the site by “scalping” the grass with the mower on its lowest setting. Then lay down layers of cardboard or newspaper. Wet to start the decomposition process. This area becomes home to “powerhouse” microorganisms and worms that break down ingredients to create a rich soil with a lightweight texture.

The garden starts as 24 inches of alternating layers of compostable materials that cook down to 6 inches.

The cold compost system rule of thumb is a ratio of two parts carbon to one part nitrogen in alternating layers of browns (carbon) and greens (nitrogen). Browns include peat moss, straw, hay, wood chips, sawdust, chopped corncobs, chopped stalks, pine needles or dry foliage. Greens include grass clippings, manure, coffee grounds, kitchen waste and plant clippings. Avoid meats, oils and dairy products that attract animals. End with a brown layer on top. There is no need to turn or stir layers.

Be careful when using manure from pasture-fed cattle. Residual herbicides may pass into the manure and damage plants. Manure and hay with seed heads cause more weeds in the garden.

Water when needed to increase microbial activity and break down the ingredients. Gardeners should expect slugs and snails. Correct any bad odors by adding more brown ingredients.

Leave the pile uncovered unless waste is not breaking down into small, unrecognizable parts. This might happen if it is wet, rainy or cold. If this is the case, cover the pile with 5 mil plastic sheeting and weigh it down.

Let the pile cook undisturbed through October until the end of winter. In spring, plant as usual. Aufdenberg recommends planting after May to allow materials to break down.

Gardeners should reserve their best garden plants and seeds for lasagna gardens, she says. In a press release, Aufdenberg said “This is precious planting space. Consider it high-cost real estate.”

Aufdenberg’s favorite plantings include tomatoes, peppers, lettuce, spinach and root vegetables. Root vegetables grow extremely well and pull easily at harvest. If using seeds, plant no more than a quarter inch deep with a light covering of soil.

Aufdenberg recommends having your soil tested. MU Extension’s Soil and Plant Testing Laboratory offers low-cost soil testing services. Visit soilplantlab.missouri.edu to learn more.