Our first skill share of the season is coming up on May 19. This will be the 3rd year that we have offered skill shares or workdays as a way to invite people onto our farm, share our experiences with no-till farming, and get some help working on our projects. We are offering these skill shares on the 3rd Saturday of each month from May-September, 2pm-5pm. Each skill share will start with a tour of the farm and an overview of all the different methods we have experimented with for garden creation. We’ll then work on a project such as sheet mulching, building terraces, or creating an herb spiral. After getting your hands dirty we end with a meal. Directions and contact information can be found on the page above, please let us know in advance if you plan on coming out to a skill share.
So- you may be wondering what sheet mulching is. I’ve managed to mention it quite a bit in various posts without ever giving it an explanation. Basically it is a method to create garden space by smothering the existing vegetation while adding lots of fertility and organic matter. Sheet mulching can be done in a lot of different ways. We encourage experimentation, using affordable materials that are available locally, and not getting hung up on specific inches of this or that.
Here are the basic steps:
- Make sure the space you are about to cover is moist- if it hasn’t rained in a while, hose it down. Once there are lots of layers on top it can be hard for water to penetrate for a while. You can start with sod, mowing isn’t necessary unless it makes the process easier.
- Add any soil amendments you feel essential (we usually just add lime at this point)
- Cover the space with cardboard or thick layers of newspaper. You need to over lap any seems well. Large cardboard boxes make life easier ( appliance and furniture store dumpsters are key). Remove as much tape as you can. Don’t attempt this on a windy day, it can be very stressful. It helps to have all your materials ready at hand before you start lying cardboard because it will need to be weighted down quickly. If you are covering a large area it helps to lay cardboard in sections then start adding the next layers rather than trying to lay the whole garden out in cardboard first because it is too hard to keep from flying away.
- From this point on you basically add mulch or manure that will help weigh the cardboard down and keep it covered and will eventually break down to feed your plants and improve your soil. The exact inches to apply vary, but it takes a lot more than you might imagine. We usually add a combination of manure and compost on top of the cardboard around 3 inches thick. After this we add thick mulch- this can be grass clippings, leaves, hay, wood chips or straw. We used to frequent some local stump dumps bringing home truck loads of mulch material, but we have become nervous about persistent herbicides or unknown chemicals that can be in grass clippings or leaves. The mulch material we depend on is hay. It is affordable, storable, and can be found in large transportable quantities. Wood chips work well for perennial planting spaces. If you continue to mulch and keep the soil covered then weed seeds are not a big problem. Weeding is never eliminated though- this isn’t magic.
- Sheet mulching works best if you can wait a year to plant into it, then it will be nicely broken down when you are ready to garden. However, we are always creating more garden space for our immediate needs, so we have sheet mulched and planted into it right away plenty of times. It is slow and irritating if you have to plant into fresh sheet mulch but it works fine. When you plant into sheet mulch you need to make sure you break through the cardboard to give your plants access to the real soil. If the cardboard is still hard we use a knife or a serrated garden tool called a hori hori to break through. If you want to plant something that is direct seeded like beans or peas just pull back the mulch where you want to plant and make a furrow. If the sheet mulch is fresh it is best to add some finished compost into the furrow so that the seeds have something to get going in until their roots are established enough to reach down through and access the soil and composting materials around. It is difficult to plant fine seeded plants like baby greens and carrots in chunky sheet mulch until it is somewhat broken down. After the bed is more broken down you can pull back the mulch and seed into the soil below.
- Generally keeping soil covered with mulch and not compacting it with your footsteps or machinery results in soft plantable soil for seasons to come. Earthworms, fungi, and roots make tunnels through the soil and break down adding aeration and organic matter. To maintain sheet mulched garden beds you shouldn’t need to redo the cardboard process again unless weeds get out of hand. If soil needs loosening we use a digging fork or broad fork but don’t flip the soil. Here’s a look at the sheet mulching process in one of our gardens.
I mentioned before that sheet mulching isn’t magic. Planting into thick mulch can be tricky, there are higher slug and snail pressures, and sometimes-thick sod just doesn’t die easily. Despite the challenges we have still found sheet mulching to be effective in creating great garden space and greatly improving soil fertility, structure, and water holding capacity without the need for mechanized tillage. Feel free to send questions our way or come check it out in person at one of our skill shares. The best way to learn about the process is by starting on a small scale and just doing it.