Raised bed gardens have become hugely popular in recent history. Perhaps it’s because more people who live in towns and even crowded cities, have become interested in gardening. While raised bed gardening is a no-dig method and a great way to grow a lot in a little space, it can be cost prohibitive. There is a less known alternative method to gardening in a small space called lasagna gardening.
The list of advantages to lasagna gardening is a long one: 1) It can be customized to fit each gardener’s needs and resources – if you have a sunny spot you can probably grow a lasagna garden, 2) it requires no tillage or the expensive machines necessary for it, 3) it is extremely water conserving, 4) it is an intensive production method growing the plants closer than you could in a traditional garden, 5) it is efficient in time because the work is done up front and once established it is easily maintained, 6) it is efficient in money because the initial start-up expense is minimal or none, 7) instead of “digging up the soil” you “build it up”, and 8 ) it can be a fun family affair introducing even the youngest of kids to gardening.
There is really no exact formula for this form of gardening. The only “rule” is to alternately layer 2 inches of brown mulch (for carbon) and 2 inches of green mulch (for nitrogen) with at least one layer of composted manure in the mix. (Our preference is well composted horse mature with stable litter). The brown mulch can include leaves, peat moss, and hay, BUT BE CAREFUL ABOUT ADDING TOO MUCH HIGHLY ACIDIC, SLOW DECOMPOSING MULCH LIKE PINE NEEDLES OR WATER OAK LEAVES. The green materials can include grass clippings, weeds (that haven’t gone to seed), and vegetable scraps. In addition to this you can also add all the coffee grounds, tea leaves, egg shells and any other kitchen scraps that would be suitable for a compost pile. In essence a lasagna garden is just an “organized compost pile” in which you grow things! This layering of the correct material, with the inoculations to get it started, causes the composting to work surprisingly fast, turning the whole thing into dark fluffy dirt.
As with other no-dig methods, there is no ground prep necessary, and no ground that won’t work. We have a friend who lives in town with a small backyard. She successfully built her lasagna garden over the very compacted gravel of a former driveway! Once a sunny spot has been chosen, just cut the grass as close as you can and start layering.
While there is no “right” way to this method, here are some tips we have learned from our experience: First put down some form weed barrier after you have cut the grass. You could use a commercial barrier, newspaper, office paper, or cardboard. We have always used newspaper, because it is readily available and completely disappears within one growing season. One year we asked our local newspaper office if they had old papers we could have. They did not, but instead, gave us several “end” rolls off the press. That supplied us for a couple of years and was convenient and labor saving. Slick color print can be used, but along with cardboard takes longer to break down and the color ink may add chemicals to your compost pile that you don’t want in your vegetables. We have found it works best to thoroughly soak each layer of the lasagna garden as it is added, including the paper layer. This holds the paper in place and gets water all the way through the bed so it can start composting sooner. We once tried to water a bed after it was built and it took a very long time for the water to penetrate the entire depth.
MATERIAL SOURCES
At least one 2-4 inch layer of composted manure is essential to the growth of a lasagna garden. If you do not have access to free manure, you can purchase composted manure, such as “Black Cow”, at a nursery or any store that sells plants. Composted horse manure is the most recommended, and we have actually used fresh horse manure with good results. The key is not to use too much. We learned of a man in our town that was bagging his stable manure every day and hauling it several miles away to dump it. We knocked on his door and asked if we could have a few bags occasionally. This was when we were first beginning our lasagna gardening, and since we didn’t have time to compost, we used it fresh as the bottom layer and the middle layer. It worked well. (Eventually, we worked out a deal with him to dump his bags beside our garden. He was glad to do it because it saved him a longer drive. We would then empty the bags, which also contained wood chips, into a pile and soon had a great supply of composted manure for free.
Lasagna gardens can be started any time of year and added to at the end of each crop rotation. If started in the summer, there is always a good supply of grass clipping just laying on the side of the road waiting for you to pick it up. In the fall your good neighbors are probably gift wrapping their valuable mulched leaves in big black presents for you. Just collect the material as you find it and pile it near your lasagna site. Don’t worry about turning the stock as you would a compost pile, just allow it to sit in “storage” until you need it. It will start to break down and create a bottom layer of rich potting soil while the un-composted top layer of material can be used in your lasagna bed.
Planning ahead is important and makes it a lot easier. Grass clipping are hard to find in the winter and leaves are hard to find in the summer, but if you have a collection on hand you can build your lasagna bed any time you wish. Another suggestion; if your neighbor has a lawn service, the company would probably be happy to empty their mower bags in your yard. For years our neighbor’s lawn service has given us their clippings! Creative thinking (which is also frugal thinking) can lead you to a ridiculous amount of options.
CONSTRUCTION
Lasagna beds can be “organic” but they don’t have to be. Water soluble fertilizers (like Peters) can be a helpful option because some of the nutrients a plant needs is taken in through the leaves. I occasionally add a little chemical fertilizer (13-13-13) to give my plants an early boost and I have considered adding a slow release fertilizer, such as Osmicote, to the layering. (If you try it, please let us know the results!) You will probably not need to add lime to your bed as the PH of the composted soil will be within the range required by most garden plants.
While some people suggest covering your bed with black plastic for a six weeks to allow the composting to start, we have found that once you build your bed, it is immediately ready for planting if you will add a little potting soil to get the plants started. We have heard some say that they spread several inches of potting soil over the whole bed after the final layer, but there is an easier and more efficient way. When you are ready to plant, simply use your hands to “dig” a hole about the size of a one gallon pot in the lasagna bed where you want the plant and fill it with a good quality commercial potting soil (or dig it out from under your stock pile of leaves). Plant the plants in this soil as you normally would and water them in. The distance between plants in a lasagna garden is about 1/3 closer than that of a traditional garden because the soil is so rich and the water is so efficiently used. For example, we plant tomatoes in our traditional garden about 36 inches apart but in our lasagna gardens we plant them 18-24 inches apart!
Because your plants are so close together, they will shade out most weeds. If a weed does manages to get started, just pull it out. Never hoe a lasagna garden, there is no need. The mulch and the close growing plants will take care of most of it. Make your beds small enough that you can reach to the middle of it without stepping on the bed. We make ours less than four feet across. (Roy made a 9 foot diameter circular lasagna bed with a 9 inch wide walk path down the center for a friend … let us know about your creative gardens!)
It is important to not walk on the bed and compress it because the bed is a big thirsty organic sponge that holds the water until the plants need it. In dry weather you may need to water the garden, but you will find that the lasagna garden holds water much better than traditional gardens. We have installed drip irrigation (which is very efficient and helps prevent disease) and we have used a water hose with a “water breaker” sprinkler. Any time during the building, planting, or growing process, you can release earth worms to speed up the composting (and it adds earthworm manure). I guess you could buy worms, but we just dig them from under the leaf stock pile. Once established the lasagna bed it is a very healthy home for the worms and they will reproduce phenomenally.
TEN STEP SUMMARY
The result of this work is a bed that is virtually maintenance free, holds in moisture and provides an environment so rich that plants can be planted closer than in traditional gardens. Our lasagna gardens have always produced larger, greener plants that grow faster and have more yield than the same ones planted in the tilled garden. It is a lot of work up front, but the harvest is worth it! Here is a summary of the whole process in 10 easy steps:
1) Collect and stockpile your brown and green clippings.
2) Chose a sunny location and mow (even scalp!) the grass as close as possible.
3) Lay down 3-4 layers of newspaper and sprinkle it with water.
4) Place a 2″ layer of manure (preferably composted) on the paper and water it in.
5) Lay down a 2 inch layer of brown mulch (the finer it is cut the better) and saturate it with water.
6) Place a 2 inch layer of green clippings on the brown and saturate it with water.
7) Repeat steps 5 and 6 until the bed is 18-24 inches high. Make sure you include AT LEAST ONE MORE layer of manure midway in the layers.
8 ) Dig one gallon size holes for the plants and fill with potting soil.
9) Plant as usual.
10) Add earthworms to taste (optional but a good idea).