As we come into the fall season it’s a great time to start thinking about planning new garden spaces. Sheet mulching, or lasagna composting, can make your job much easier. Sheet Mulching is a technique of layering organic materials, nitrogen (green) and carbon (brown), onto existing soils to create planting beds rich in organic matter by composting in place.
Some additional reasons for Sheet Mulching include suppressing weeds by composting on top of them, build soil structure by adding compost (once broken down) teaming with beneficial microbes and insects, improve nutrient levels and water retention. Lastly, recycle yard and household (compostable) materials by piling up like lasagna on top of your planned bed.
Materials you can use: Leaves, grass clippings, branches (the smaller the better), newspaper, cardboard, coffee filters, paper products, etc… There are many different combinations of materials and methods but here is one easy way of doing it.
1. Lie down or flatten existing growth where you plan to prepare bed. Pile a thin layer a few inches thick of debris on top, weeds are ok as the seeds will not be able to germinate underneath the additional layers. Finished compost mixed into this layer is a good idea if you plan to plant the space shortly after.
2. Lightly wet the area with the hose. You want the consistency of a rung out sponge, not too wet but not too dry. Adding moisture to this layer is important to start the decomposition process. Once the top layers are added it will be hard for water to penetrate through.
3. Lay down a layer of cardboard or paper. Feel free to use whatever you have lying around, just be sure to use only materials that will break down, no plastic. Make sure to overlap each piece of material by a few inches so there are no gaps, unless you plan on planting in specific areas. Once again lightly wet this layer.
4. Add another thin layer of organic material. This should be approximately 3 inches thick but anywhere close is fine. In this layer I like to use grass clippings and leaves because they break down faster than woody debris. To top it off spread a layer of compost and soak with water. The compost gives the bed a clean, finished look while also starting the decomposition process. You don’t need to stop there if you want to keep stacking layers, just be sure to keep mixing in both green and brown materials to keep a good carbon to nitrogen ratio.
5. Plant right away through the layers or wait a season until the material has a compost/soil composition. I like to do this in the fall so beds are ready for spring.
Work smarter, not harder!