Sheet composting is similar to trench composting in that it is cheap and low-maintenance once you’ve set it up. In this technique, you simply place layers of compostable materials on your garden beds and wait until they decompose to plant there.
These layers are usually started with multiple layers of newspaper or one layer of corrugated cardboard, which is soaked with water to keep it from blowing away. The second layer can include nitrogen-rich material like chicken, steer, or horse manure, grass clippings, or food scraps. The third layer can include shredded twigs, leaves, sticks. Here and here are some guides for sheet (or lasagna) composting and what to add.
Here are some things to keep in mind when deciding if sheet composting is right for your school garden:
- This is a no-till friendly method, unlike trench composting, and you can expect fewer problems with weeds than in other gardens.
- If you want to start your garden in the spring, you will need to add soil-like components before you can plant your garden – topsoil, peat, or potting soil will work. The ideal time to start a lasagna garden is in the fall, so the layers can break down by springtime.
- This works best if you can put down all layers at the same time, or at least layer by layer so that decomposition is happening equally throughout your garden. You will need to be able to store your compostable materials somewhere until you have enough.
- This method of composting isn’t going to make your garden look great, so if that is important to you or the school’s neighborhood, take that into consideration.
- Although you won’t need to dig anything for this method of gardening, you will still need to be able to use a wheelbarrow to haul in enough material for each layer. Make sure you have enough people around to establish the layers, and consider planning a work day around it if necessary.
- Make sure to wait until the layers are fully broken down to start planting. Otherwise, you may struggle with slugs who have taken up residence underneath the layers or you may notice that your plants aren’t getting enough nitrogen since decomposition is not complete yet.