I have been moving away from the standard gardening method of tilling the soil every spring. For years I would break the tiller out as soon as the ground was warm enough to work and go to town on the garden beds loosening up the compacted soil and making a nice soft bed for my new plants to be placed into.
Along with the tilling came the addition of fertilizers and mulch to help feed the new plants and keep the weeds at bay. It always seemed like a never ending battle to keep plants well fed and weeds under control and I never got the results that I was looking for.
After much research I discovered that my annual tilling was doing more damage than good. True, it was breaking up the compacted soil but along with that it was destroying the life of the soil (hence the need for fertilizers). What I really needed to focus on was keeping the soil from becoming compacted in the first place by feeding it well and helping it develop. That’s when I discovered the idea of sheet mulching.
What is sheet mulching?
In simple terms, sheet mulching is pretty much what it sounds like. It is mulching in “sheets”. You may have heard the term referred to as a “lasagna garden”.
Basic sheet mulch has at least 4 layers
- Cardboard or newspaper
- This is the weed suppression layer and goes down first (make sure to mow the area short first).
- Use standard cardboard free of plastic tape and stickers.
- If you don’t have access to cardboard you can use newspaper. Avoid using the glossy add pages.
- Overlap the edges and do two layers if you can to prevent stubborn weeds from working their way through.
- I prefer to use cardboard. I can get all I want for free from one of the local fast food places (they were more than willing to have me pull it out of the recycle bin out back) and I feel like it does a better job than newspaper.
- If you have access to cold manure (like rabbit or goat), well aged hot manure (cow, chicken, etc.), or high nitrogen organic matter (fresh grass clippings, vegetable scraps, etc.) add a layer of that across the top of the cardboard. This can be skipped if you need to but I recommend adding it if you can.
- High carbon organic matter
- A 2 or 3 inch layer right on top of the cardboard.
- I mainly use straw if doing a large area because it is readily available at the local feed store and sometimes I can get it for free after the holidays when everyone is throwing out their fall decorations (watch Craigslist or put out the word at your church and on Facebook that you are in need of straw bales)
- Grass clippings also work very well but I usually can’t get enough of them from just mowing the lawn.
- Wood chips are another good source of carbon if you can get them for free (my town gives them away a few times a year).
- Finished compost or good quality top soil
- Add about 2 inches of finished compost right on top of the carbon layer. If you can’t get compost use a good quality top soil or even soil from another location on your property (avoid soil with grass seeds in it though).
- This is probably the most expensive layer. The city I live in has a composting facility. It is self-serve but it is free so for a little bit of work (it has to be sifted) you can get all the compost you need.
- Top Cover
- Don’t leave all that fresh soil or compost uncovered. Mulch heavily with organic mulch. Grass clippings, straw, wood chips, mulched up dead leaves all work well.
- Water the entire thing well before placing mulch on top. This will help retain moisture and get the breakdown process started.
- In a pinch you can cover the ground with a tarp if other mulch is not available. You will need to mulch once the tarp is removed and the area has plants growing though.
The benefits of sheet mulching
First of all, sheet mulching builds your soil. By adding all that organic matter to the soil it develops a life of its own. Helpful fungus and bacteria will flourish in the new area and begin breaking down the layers and feeding the soil.
The multiple layers of the sheet mulch hold moisture and reduce the need for watering. I was able to cut my watering needs by over 50% compared to previous gardening seasons.
Expect to see a significant reduction in weeds. There are two basic reasons for this. The first of course is the fact that you are smothering the weeds out with the bottom layer of the mulch. Even more important is that you create a high nutrient soil. Weeds are nature’s way of repairing damaged soil. When you have higher nutrient soil, weeds just don’t germinate as well. You will still get weeds from time to time but not anywhere as many as before.
You no longer have to till your garden either. Because the soil is healthier than before, it stays aerated and does not become compacted therefore eliminating the need for tilling (and avoiding the damage it does).
Eliminate or significantly reduce the need for additional fertilizers. I was able to completely eliminate the need for additional fertilizer. The high amount of organic matter added provided all the nutrients the plants needed and I had much better results than I ever did with the use of off the shelf fertilizers.
Sheet mulching is pretty simple. There are all kinds of things on the internet showing you how to make killer sheet mulch and talking about adding different minerals and rock dusts, etc. All of those things work and by all means do it if you can but don’t get hung up on having to do it that way. That stuff can get pretty expensive and you can get pretty good results with the steps I laid out above (see the video below for my results).
Avoid using wood chips that contain walnut, cedar or pine. These trees produce chemicals that inhibit plant growth. As long as your carbon layers are not mostly these types of trees you should be fine so don’t get overly paranoid about it.
One more thing that I almost forgot to mention. Your sheet mulch will do much better if given some time before planting into it. I like to do mine in the fall and then plant in the following spring.
I sure hope that you found the information useful. If you have questions, comments or additional tips please leave them below. I look forward to reading them.
Thanks for reading and God bless.