Lasagna Gardening 101

When we till the soil, we are essentially killing the intricate network of life below the ground upon which the life aboveground depends.

Dr. Elaine Ingham, Founder, President, and Director of Research for Soil Foodweb Inc, says that tilling causes most soil problems. 

She also reminds us to keep our garden beds pesticide-free:

Because soil fungi are so extensive and so entrenched in the landscape, it can virtually “field” nutrients to those plants and fellow fungi that need it from one part of your yard that has these nutrients in abundance.

One of the superstars of the mushrooms world is mycologist Paul Stamets. Stamets explains the fascinating network of mycelial threads in his book, "Mycelium Running: How Mushrooms Can Help Save the World."

When we till, we break those fungal connections. We kill and churn up the beneficial bacteria and micro-organisms in the soil.

Initially, our soil may have a surge of oxygen, but after some time, without the life to maintain the soil structure, the ecosystem falls apart.

Sadly, many community garden plots till the soil annually, forcing garden plot renters to start from a blank canvas of lifelessness each year.

If your soil is compacted, use a “broad fork” or something that aerates the earth, without chopping up the earthworms and fungal strands in the ground.

Sadly, many community garden plots till the soil annually, forcing garden plot renters to start from a blank canvas of lifelessness each year.

This is just (1) one example of many for ordering the layers in your garden bed.

When creating your lasagna garden, remember the principle,

“Do what you can, with what you have.”

Rather than going out to a store to purchase mulch, for instance, see if you might not have some leaves around your property that simply need to be raked and can use as a lasagna garden “layer.”

We always start with cardboard at the bottom.

The cardboard acts not only as a weed barrier but somehow mimics the bedrock layer of the soil on the upper crust of the earth.

Lay down the cardboard, overlapping the pieces about 6-inches, to block off the weeds. This weed barrier will save you from having to pull them all out later. Less work for you.

Please note: You will likely still have weeds in your garden even after putting down the cardboard, but they won’t be as aggressive as they would be without using a cardboard weed barrier. The weeds, if any, will grow less and less every year as you build up your fertile soil.

In the diagram above, you see the “kitchen scraps” layered beneath the cardboard. It's good for you to do the same because you want to make sure that no animals start smelling the scraps from your backyard. They may dig them up before the food has time to decompose.

The photo above shows how this California gardener needs to overlap his cardboard more so that there are no gaps and the weeds can't go through.

The top of the lasagna garden for us is always a beautiful bed of straw mulch.

Straw mulch works well in the heat and works well in the cold. It eventually disintegrates and becomes part of your soil layers. But initially, when it is newly placed, it helps protect the soil from evaporation and extreme frost.

It’s like a blanket!

The middle layers can consist of whatever you have on hand plus the organic compost/soil mix that you initially use to build your garden.

Introduce life in the middle layers. You can add life forms such as nitrogenous bacteria, mycorrhizal fungi, and earthworms to these layers.

Here's the same garden above layered with compost and topsoil.

It's helpful to use scissors and snip the straw mulch up into smaller cuttings so that they don’t stifle the plant growth underneath.

Some permaculture gardeners use woodchips instead of straw mulch and have found them to be effective in capturing moisture as well. The only problem with woodchips is that the wood, which is high in carbon, tends to look for nitrogen to use towards its decomposition.

If your garden bed is brand new, this could mean losing much-needed nitrogen in the process. And that is why we recommend straw in most gardens.

It is always good to define where your garden bed stops and starts. This physical definition is especially true when working with kids who will tend to step into the garden bed even if it is raised. Stepping on a garden bed can cause soil compaction and acidification, so we try to minimize that as much as possible.

When choosing appropriate materials to "edge" or form the borders of your bed, we recommend something that can stand up for a long time, such as brick or cinder blocks.

Cedar is also an excellent wood choice, but it tends to rot after about (5) five years and needs replacement. Douglas fir is a cheaper alternative to cedar. 

Avoid using “pressure-treated” wood, which also happens to be chemically-treated, as well as pressure-treated.

Some of the members of the Grow-It-Yourself / GIY Membership program have found success in using a “wall block” to stabilize the corners of their raised square-foot beds and then using wooden planks to build the “walls” of your lasagna garden. An example of that block is in the image below.

Watch the video below to learn how to build a lasagna garden from scratch using whatever materials you have on hand.

You can transplant in your garden right away. Simply poke a hole through the layers, large enough to allow space for your transplant’s roots to spread.

Or you can wait two weeks to have your garden rained on and decompose naturally so that the microbiology in it can establish itself.

John Jeavons, creator of the successful Grow BioIntensive methods recommends starting your plants from seed and transplanting your seedling into the garden once temperatures allow, and the plant has at least “two true leaves.” 

However, if you are in the middle of summer or late spring and you would like to catch up with the optimal growing seasons, you can direct sow specific seeds as long as the germinations temperatures are optimal (usually 60–70 F).

By using straw, you might prevent your directly sown seeds from germinating.

This risk is yet another reason to prefer transplanting over direct-sowing. Yes, straw may block the light needed for some seeds to germinate. However, if you cut up your straw very fine all you have to do is shift the straw over a bit in the sections in which you direct sow to allow the seed to get direct light and access to the soil.

However, if you are in the middle of summer or late spring and you would like to catch up with the optimal growing seasons, you can direct sow specific seeds as long as the germinations temperatures are optimal (usually 60–70 F).

Nothing. Weeds are often misunderstood plants. Their presence may indicate that:

• The straw mulch you used contained unwanted weeds
• The wind blew some weeds into your garden bed
• Your soil needs remediation of some sort. So when you see them, ask yourself,

1. 1. Is that area not yet fertile enough?
   2. Does it get trampled on a lot?
   3. Is it compacted or eroded?

In a past article on Building Garden Diversity, you will find a list of weeds used for soil remediation.

In permaculture, weeds are considered “pioneering plants” that pave the way for more useful vegetables. As you find them in our gardens, allow yourself to be curious about their presence and purpose. Sometimes you’ll be surprised to see the medicinal uses of plants like dandelion include: 

• healthy digestion
• lowering cholesterol, and 
• controlling diabetes.

Nevertheless, a whole bed of dandelions, however, is not desirable.

So pull your weeds out as soon as you see them and plug in a more desirable plant in its stead. You will find fewer weeds in your first lasagna garden year and fewer still, the following years.