How to Amend Clay Soil

You may be worried that you won’t be able to grow anything in your clay soil but I promise you can learn how to amend clay soil to grow your own food! The short answer to the question, “How do I amend my clay soil?” is to add organic matter. This article details 5 easy ways to amend clay soil with organic matter that will create delicious, robust soil for growing a garden.

Here are a few more soil articles for later:

How to Fix Rocky Soil with Permaculture

How to Fix Sandy Soil with Permaculture

How to Amend Soil with Permaculture

I suppose the first question to answer is, “Why does clay soil need to be amended?”

Clay soil can be tricky to deal with in a garden setting because it tends to be very heavy, get easily water logged, and dry to almost stone-like strength.

It’s not all bad, though. A little clay in your soil profile can actually do a lot of good things!

Clay soil can hold water, unlike sandy soil that has an overabundance of drainage.
It also provides porosity to the soil structure, which determines how well the soil can hold warmth, as well as water.
Clay soil is useful as a building material, as with cobb structures, straw bale houses (which are often finished inside with clay plasters), and fun projects like outdoor ovens and dorogango balls.
Clay can also contain calcium oxide, which is a component of lime plaster (also used in natural building, typically as a finish plaster).

However, as I mentioned, when found in large percentage in your garden soil, clay can also:

Hold too much water, not allowing water to drain away from plant root systems, which can cause rot.
When dried out, clay soil is VERY difficult to work – dig, break apart, etc.
Clay soil can be very heavy, which needs to be a consideration for older or injured gardeners.

In short, heavy clay soils are big bullies in the garden and making the task of growing our own food more of a challenge.

However, it’s a challenge with a solution! You and I can learn to appreciate what’s useful about our havey soil, while learning how to amend clay soil.

The Key to Learning How to Amend Clay Soil

–>>Add organic matter! <<–

This is just about the answer to every soil question you may ever ask. Why? Because it works to improve the soil every time it’s applied!

Today’s article will highlight for you five simple ways to add organic matter to your soil with no tilling and for very little cost.

What’s Organic Matter?

First of all, we need to define organic matter so we’re both on the same page. If you’re going to learn how to amend clay soil with it, you need to be sure you know what it is!

I like Cornell University’s succinct and clear definition:

Organic matter is made up of different components that can be grouped into three major types:

Plant residues and living microbial biomass.

Active soil organic matter also referred to as detritus.

Stable soil organic matter, often referred to as humus.

The living microbial biomass includes the microorganisms responsible for decomposition (breakdown) of both plant residues and active soil organic matter or detritus. Humus is the stable fraction of the soil organic matter that is formed from decomposed plant and animal tissue. It is the final product of decomposition.” (bold type added)

The plant material, microbes, and detritus all contributes to soil health because as they break down, they release nutrients like nitrogen, potassium, and phosophorus.

Since hummus is what’s left at the end of the decompostition process, it doesn’t really add nutrients, but it does provide great texture to your soil. It’s that dark part in really good soil that keeps it light and airy. The gardening term is friable.

If you’d like some extra help improving your soil and you’d like to get started right now, get your free copy of our soil workbook by joining our newsletter family.

The Benefits of Organic Matter

Here are just a few of the benefits of having high levels of organic matter in your garden soil:

Organic matter improve the soil structure. This means that the soil is more able to hold itself together in a weather event like rain, without eroding away.
The more organic matter in the soil, the less likely your clay soil will be to dry to harpan should it be left uncovered.*
Organic matter will also help the soil not overreact to big changes in temperature and even pH (like runoff or the application of unseasoned manure). Essentially, organic matter helps the soil keep calm and garden on.
It also increases the soil’s ability to hold onto nutrients longer in the soil to feed both the plants and the microbes.
In this way, organic matter provides a quality home for fungi and even more soil microbes! Worms love the texture and health of an organically rich soil, too. These organisms are drawn to the food the organic matter provides for them.**

So much is happening in healthy soil beneath your feet that you’ll never see, but from which you’ll benefit with abundant harvests.

A Few Notes

*Never leave soil uncovered, if you can help it.

Garden mulch like wood chips and straw can be applied throughout the growing season to keep the soil surface covered to prevent overheating, protect the microbial life in the soil, and prevent water loss/drying out.

–>>Read our article more information on How to Use Mulch and Compost <<–

**As you’re building healthy soil structure and learning how to amend clay soil, it’s very important that you not break up all this microbial and fungal activity going on underneath the surface of the soil.

When you tear through burgeoning soil with a tiller or even with a lot of shoveling, you distrupt the happily sequestering microbes and break apart the fungal connections that act like a great web of life in the dirt.

Dig when you must, but otherwise, try to preserve this soil structure whevever you’re serious about improving soil fertility and growing plants.

–>>Learn How to Create a No-Till Garden Area<<–

Common “Organic Matter” Materials

Anything coming from nature could be deemed organic. Arsenic, for example, is an organic material.

For gardening purposes, there are simple sources of organic matter that require differing levels of input from the gardener in both time, energy, and money.

Here are a few:

Seasoned animal manure, called composted animal manure
Seasoned plant residue, called compost
Cover crop plantings, called green manure
Compost teas, made from seasoned plant compost

In some measure, materials placed on top of the soil as mulch can act as compost as it breaks down over time, adding organic matter of its own to the soil.

Build the Soil, Not Replace the Clay

Organic matter must be applied and then reapplied repeatedly over time to successfully amend clay soil. This is because the microbes, fungus, worms, and plants all consume what the organic matter puts into the soil.

This is exactly what they’re supposed to do! But they need constant input, especially while your soil still contains a proportionally large amount of clay.

Before we get into our five ways of using organic matter to improve clay soil, I need to toss in one item of clarification.

We aren’t replacing the native clay in our soil with organic matter. The clay isn’t going anywhere. It’s been in your soil for thousands of years and it will be there when the Lord returns in glory.

Clay is immortal. It is time itself and will never die.

We are, however, bulking up our soil profile with organic matter mixed into the clay. (Which is great because, as we mentioned, clay can do a lot of good in the soil.)

We add layers and layers and layers of organic material until we have LITERALLY grown our soil. This is what successful gardeners do, after all.

We grow fantastic soil. Then, the soil grows our food for us becaue we’ve given it the tools to do so successfully.

How to Produce Organic Matter to Amend Clay Soil

Aha, we get down to it now!

You could go out and buy organic matter to amend your clay soil. However, unless you have a very small garden and a very large budget, this will get cost prohibitive after awhile.

So, the following are five simple ways to amend your clay soil with organic matter. These methods will take time, FYI.

Amending clay soil until it’s ready to grow a garden isn’t an overnight process and you should be leery of anyone claiming it’s fast or that it won’t require some effort.

However, with consisten application of any or all of the following methods, you will be able to grow more and more food each year in your clay-based soil.

Side Note:

Bill Wilson of Midwest Permaculture teaches his students that, when we happen upon a garden challenge, we need to train ourselves to say:

We are SO lucky to have this challenge. Now, let’s figure out why we’re so lucky!

The fact is, it most often happens that our greatest obstacles in the garden turn out to be our greatest blessings. They force us to adopt new and better methods, challenge us to change things up, and to be creative in our problem solving.

This process of constant self assessment means we become the best gardeners we can be!

Amend Clay Soil with Compost

Learning to make your own compost from kitchen scraps and garden waste is probably one of the most beneficial skills you can develop as a gardener. The great part is that compost takes what would otherwise be garbage and turns it into a valuable commodity.

Gardeners are so enamored of quality compost that they call it brown gold!

Here’s how to make a Compost Bin Six Different Ways with Tenth Acre Farm.
Lovely Greens can teach you how to Make Compost the Easy Way.

There are several methods for producing compost and all of them have their benefits. Here are some to consider:

Making a simple compost bin for the garden with Creative Vegetable Gardener.
Composting in situ, or in place, and other simple methods with Our Permaculture Life.
Using a compost tumbler, homemade or purchased.

Some people like to think of their chickens as quick composters. They take garden and kitchen waste and produce nitrogen-rich poop, after all! You need to season their waste before you can use it in the soil, but it is fantastic composted manure!

Plus, you get eggs. (More on animal manure in a bit.)

Amend Clay Soil with Compost Tea

Once you’ve made quality compost, you can apply it directly to the soil, either as a top dressing or in layers of other organic material.

You can also make compost tea with it to apply via a water sprayer either to the soil or to the leaves (referred to as foliar spray). The leaves are the living food manufacturer of the plant and applying compost tea to their surfaces, top and bottom, can drastically increase the uptake of nutrients.

You can even grow plants specifically for compost and compost tea. Here are a few ideas:

Comfrey
Moringa
Alfalfa
Amaranth

Here’s how to make simple compost tea with Northern Homestead.

You can also make manure tea with Our Inspired Roots.
How to make worm casting tea with Stone Family Farmstead.

–>>Here’s how to make a compost tea bucket for brewing these teas.<<–

Amend Clay Soil with Composted Manure

Animal dung can be a powerfully nutritive amendment for any clay soil. The first thing to learn is which dungs can be applied directly to the soil and which must be seasoned (or composted) first.

Those that can be used directly on the soil are called “cool” and include:

Those that require seasoning are called “hot” and include:

I like to top dress established garden beds with composted manure once in spring, and again in the fall, if I can manage it.

Don’t forget container plants need feeding, too! Especially heavy feeders like veggies and perennial plants like potted herbs.

The safest animal manure is from your own homestead because you know exactly what your animals have eaten. If you’re purchasing animal manure, you need to be sure you know what is going to be in that manure.

Toxic animal manure can actually destroy your garden. Be cautious!

Amend Clay Soil with Layered Mulch Materials

If all you have time for this year is to gather loose organic materials you scrounge from your property or neighborhood, go for it! Always remember that an imperfect something is better than a perfect nothing when it comes to the garden.

Mulch materials to layer include:

Chop and drop mulch crops
Autumn leaves
Straw or even hay (though hay might mess with your soil pH depending on whether it’s still green)
Pine straw
Grass clippings*
Any local to you dried botanical material like corn stalks, sorghum sheaves, or foraged items like mullein leaves
Dead or dying garden plants like Jerusalem artichoke stalks, comfrey leaves, the last of the kale, or hollyhock stalks.
Sawdust*
Wood ash (don’t add too much)
Sticks and even small branches towards the bottom of the pile

*Be sure to break up clumps of these materials and sprinkle them on top of the soil layers like salt and pepper.

Amend Clay Soil with Worm Castings

Worm castings are among the richest soil amendments you can generate yourself! They integrate wonderfully into any soil building plan for clay soils.

The best part is, keeping composting worms is a great thing for small space homesteaders to do because the bin in which they live is comparably smaller than in-garden composting bins. You can provide for the needs of a potted garden on a balcony with one worm set up.

If you garden is larger, you can install worm towers in every garden bed or garden area to build up their beneficial presence in your soil over time. The towers work in the same way that the bins do.

You place kitchen scraps in the bin or tower and the composting worms eat up the material.
Eventually, the worms poop and trail their benefical waste either in the bin to be harvested or in the garden bed to diffuse into the soil.

You can learn more about either kind of worm composing in our article, “

Personally, I like having both methods in production, but I usually end up with only towers because I’m an airhead and can’t keep a worm bin going reliably.

Once You’ve Done That

After you’ve done all that, start planting a few things as you feel the soil is ready.

Try these clay busting plants presented by Tenth Acre Farm.
Consider ground cover plants whose root systems help hold nutrients and water in the soil.
Also get started with ground cover plants to cover and protect the soil.
As soon as the soil is loose enough, start planting garden vegetables with other helpful companion (or guild) plants.

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