The ideal time to build a lasagna garden bed is in fall for a spring planting. This gives the material in the bed all winter to break down and turn into rich growing medium. However, by altering the procedure slightly you can build a lasagna bed in spring or early summer and Have it ready for late summer or fall planting the same season. Here's how to make your own homemade “garden lasagna.”
Step 1: Collect materials: You can use all types of organic matter to make a lasagna bed -- grass clippings from mowing your home lawn, fall leaves, and lawn clippings from a landscaping service (don't accept clippings from lawns that have been treated with pesticides and herbicides), and mulch hay or straw from farms. (Try to find herbicide-free, organically grown hay and straw. Hay cut early in the season will contain fewer weed seeds; high quality straw is generally pretty weed-free.) Collect kitchen vegetable scraps, coffee or tea grounds, disease-free green plant trimmings, and newspapers as well.
Step 2: Level existing vegetation. Mow the area, leaving clippings in place, or cut down tall grass and weeds as low as possible.
Step 3: Define your beds. Use stakes or a garden hose to mark the edges of your bed or beds. Make each bed narrow enough that you can reach the center without straining. Two to three feet wide is a good width for young children; three to four feet wide works well for teens and adult gardeners. This way, you and your kids can tend to the beds from the path, without stepping into them, and avoid compacting the soil.
Step 4: Smother it! Fill a tub with water and moisten 4 to 6 sheets of newspaper at a time. Lay the damp paper over the defined area, overlapping the edges by at least two inches. Or you can lay down dry sheets of newspaper; then soak them thoroughly with a spray of water from a hose. This step smothers the lawn, killing the grass over time without any digging on your part! As a bonus, the decomposing grass plants will add beneficial organic matter to the soil.
Step 5: Make the Lasagna. Spread 2-inch-thick layers of the organic matter on top of the newspapers to form the bed. Alternate green layers (grass clippings, kitchen scraps) with brown layers (hay, peat moss). Keep off the bed as much as possible while making the layers to reduce compaction. Spray each layer of dry materials with water until it is as damp as a well-wrung-out sponge before adding the next layer. If you use hay or other materials that might contain weed seeds, put them in the lower layers in your lasagna to minimize weed growth. Keep adding layers until the bed is 12 inches high.
Step 6: Planting. If you build the lasagna bed in fall, leave it over the winter to allow the layers of organic material to compost. The height of these layered materials will decrease as they begin to decompose, and the temperature within the bed may rise as decomposition proceeds, just as in a compost pile. Your bed, filled with crumbly finished compost, will be ready for planting the following spring. If you plan to plant within the season, wait a few months until the layers of organic materials have partially broken down and are no heating up before planting. Add a mixture of soil and finished compost to the planting holes of these one-season lasagna beds as you set out your plants.
To get started, make a list of vegetables and/or flowers you'd like to grow. Design your bed, keeping the proper spacing between plants in mind. For transplants, pull mulch away to create a hole large enough for the plant’s root ball; fill the hole with compost and set your plants in place. To sow seeds, sift two inches of compost or soil over the surface of the mulch, plant the seeds, and cover them with more compost. Keep the seedbed moist, and as soon as the seedlings emerge, gently pull mulch around them. Monitor seedlings and young transplants daily to make sure they have enough moisture. By fall the roots of your plants will have spread throughout the bed.
MAINTAINING LASAGNA BEDS
Keep the bed well-watered. Drip irrigation and soaker hoses are ideal, but watering by hand is fine, too. You can also use one-gallon milk jugs or 2-liter soda bottles as free, slow-drip watering tools. Using a small nail, punch holes in the lower half of each jug -- on both bottoms and sides. Bury the jugs in the bed near plants and fill them; they'll leak water slowly into the soil for the plants to use. Pull any weeds that sprout on top of your bed, and add an extra layer of mulch once the plants are actively growing. This last layer will help to conserve soil moisture and reduce weeding through the summer.