Lasagna Gardening (Sheet Composting)

A common complaint in our area is the hard, compacted clay soil. While clay soil is actually one of the most nutrient dense soil types that you can have, it can be difficult to work with if it hasn’t been properly cared for over the years. A really simple and relatively hands-off way to break up that hard clay and prepare for an easier and more successful growing season is to utilize a soil preparation method called Lasagna Gardening or Sheet Composting.

Lasagna gardening is a method of soil preparation that involves layering “brown” carbon-rich materials (like dried leaves, cardboard, or paper) and “green” nitrogen-rich materials (like grass clippings and food scraps) like a lasagna on top of the soil that you would like to prepare for planting. 

Can I use this to turn my lawn into planting space?

Yes! There are several other benefits to doing this type of soil preparation beyond just massively improved soil health! It also reduces weed growth and can be an almost totally hands-off way to get rid of a grass lawn without any digging or tilling involved (being stuck below the cardboard blocks the grass from sunlight and air, inhibiting photosynthesis and ultimately suffocating the grass which then becomes another “green” layer).

How and When to lay down your lasagna garden

The process is really quite simple. Once you decide where you want your garden to be, you can start by first layering some “brown” material (that’s the cardboard/paper), then “green” material (clippings and food scraps). Then, hence the name, you continue to alternate layers like you would for a lasagna until you’ve run out of materials. It’s important that you water the soil throughout this process, as the water is a crucial component in the decomposition process. I would recommend spraying down each layer as you go. After completing your layers, it’s important to water semi-regularly to keep the soil moist but not flooded. If you are establishing your soil in the fall and you have a good rainy season then you can just allow nature to take its course without any intentional watering on your part. 

This is best done in the fall before you wish to plant so all the materials have time to decompose and break up the soil but it can be done anytime. If you are wanting to plant immediately the best course of action would be to add your brown and green layers and then add an additional 3-6 inches of prepared top soil to plant in. 

Can’t I just add sand for drainage instead?

Absolutely not! Depending on your soil type you may be able to get away with this but I would never recommend it for our area. While sand is a good drainage option in some compost and potting soil mixes, it actually causes a reaction with clay soil that creates a dense concrete-like consistency. Ironically enough, if you have already mixed sand and clay and find your soil as hard as rock the best solution to remedy it is …. Lasagna gardening! The decomposition process will help to break down the dense texture of the soil.

Conclusion

Lasagna Gardening or Sheet Composting is the ultimate way to prepare your planting area, whether you are planting immediately, preparing for next season, or trying to replace your lawn with new garden space. As somebody who definitely prefers working smarter rather than harder, this is my go-to for soil preparation.