Wait, you can start a garden in the dead of winter? Yes, you can. In fact, for certain types of no-till growing, this is the very best time to launch your 2022 garden. We’ve discussed a kind of no-till gardening called Square Foot in the past. One of the many advantages of Square Foot is that you can start it anytime. You could, in theory, build the raised bed in the morning, fill it with soil in the afternoon, and plant it that same evening. Most no-till techniques, however, require a little bit longer lead time. Today, I want to talk about a method called deep compost.
Deep compost no-till gardening is favored by larger-scale home gardeners and many market gardeners. The cost per square foot is significantly lower than raised bed methods, allowing more growing space without an unsupportable capital investment. It is also more similar to traditional row-tilled methods and can utilize many of the same planting and harvesting tools.
The process of building a deep compost garden is simple if perhaps a little strenuous. The idea behind deep compost is, well, a deep layer of compost placed on a barrier medium directly over untilled soil. The barrier medium is usually cardboard or kraft paper, and it provides temporary weed control while the bed is “percolating.”
As a deep compost gardener, you begin by laying out a plot with string and stakes, alternating 30-inch “rows” and 18-inch “paths.” The rows and paths can be any length. The paths are necessary so that the rows – the planting areas – are not compacted by foot traffic. The rows are 30 inches because most adults can reach the center from the path without compacting or disturbing the soil.
Once the layout is complete, you remove any loose sticks, rocks, etc., from the area and mow any grass or weeds as close to the ground as possible. Breaking up (not tilling) the top layer of the soil with a spade or broadfork is recommended but not necessary.
The entire plot then gets covered with a layer of cardboard. Cardboard can often be had for the asking from the waste bins of retail stores, but if you do not have access to this free resource, you can buy rolls of 3-foot by 100-foot kraft paper for around $15. You will need to use at least two layers of paper in place of one sheet of cardboard.
Finally, a four-to-six-inch layer of compost and wood mulch goes on the rows and paths, respectively. This is the backbreaking part, but the effort is well worth it because once you are finished, you’re done “gardening” for three months. During that time, moisture percolating through the compost feeds the beneficial organisms in the soil, breaking down the cardboard barrier and breaking up the top few inches of earth below. When late March rolls around, the bed will be ready to plant.
So, surely you are asking, “What’s the catch?” Like most no-till methods, deep compost gardens are less-productive in the first year or two than tilled gardens, as the root structure of the plants works to break through the soil. Depending on your soil type and compaction, the difference in productivity can be anywhere from 10 percent to 50 percent. By the third year, though, a well-maintained deep compost garden will be nearly as productive as a traditional tilled garden of the same size.
Acquiring the necessary amount of compost can also be a challenge in some places. In my area, the local landfill offers decent-quality aged compost for just $20 per yard, but I know some gardeners who have to pay five times that. Finally, if you live in an area where the soil is extremely rocky, it may be challenging to use this method effectively.
In general, though, if you are looking for a way to create a more extensive garden to help feed your family or even a market garden to earn some additional income, deep compost may very well be right for you. If you are interested in learning more about this no-till technique, this video provides an excellent tutorial of the entire process.