Clay Soil—the perfect soil for your garden? (2024)

New amendments for improving your heavy clay soil...

There are quite a few well-written articles around the web that cover gardening in clay soil.

If you have ever read any of those articles, then you already know that adding compost to heavy clay soil is the primary process to improving that wet & sticky stuff’s ability to grow a healthy lawn and garden. But, why is this? What changes? How does it all work?

What does compost add to your ground that improves clay soil?

Compost breaks down into humus that coats and buffers the clay soil particles and lessens the cohesion between them. It also feeds the bacteria and microorganisms that soften and restructure the clay as well as adding nutrients for new plant growth.

Clay soil problem solved, right? Mix in a little compost and we are good to go. Not always.

To transform a heavy clay soil into a productive growing soil can require A LOT of humus. Because clay is very good at storing all soil elements, both good and bad, it can sometimes not provide the best humus creating environment. One area that your soil can be severely lacking in, is having healthy amounts of the bacteria and soil microorganisms that turn the compost into humus.

There are new liquid soil amendments that can heal and accelerate the humus building processes in clay soil. These amendments add humus directly as well as repair any unproductive conditions in the soil, like high levels of salt, herbicides or a nutrient imbalance.

Adding biological amendments and liquid humates can dramatically accelerate the clay soil improvement processes.

Let's review some of the clay soil basics.

What is clay soil? All soils are composed of eroded rock. The difference between soils is the size of soil particles. There are three primary sizes of particles:

• Sand - A sand particle is classified as smaller than gravel but larger than silt. Soils considered sandy are composed of more than 85% sand-sized particles.
• Silt - Silt is a medium sized rock particle that is smaller than sand but larger than clay.
• Clay - Clay soil is composed of the finest rock particles—less than .002 mm. Clay is the result of extreme rock weathering over time and then being deposited by bodies of water. If your soil is made up of over 50% clay particles it is considered heavy clay—and it will need improvement to be a viable source of nutrients for just about any type of plant life.
  

How do I know if I have heavy clay soil?

If you’re not sure what type of soil is in your yard, here are a few helpful indicators that you can use to identify your soil type.

• If your soil is hard when it’s dry, and it doesn’t crumble easily when you squeeze the soil in your hand, then that can indicate a certain amount of clay particles in your soil. Larger soil particles do not have the same cohesion as the small clay particles, and therefore they tend to crumble more easily when squeezed with your bare hands.

• Clay soil can feel and act like Playdoh when wet. You can squeeze and roll it into a ball and it will hold the shape. Sand and silt soils will not hold the shape.

• If you are still not sure, don't worry about it. All types of gardening soils can benefit from humus and good soil management.

Why is clay soil bad for gardening?

A heavy clay soil is composed mostly of tiny clay particles. These particles tend to compact together. This compaction can cause quite a few problems for growing a healthy lawn or garden. Here are a few of the most common problems:

• Poor Drainage - Because of the lack of air pockets, clay restricts water movement and drainage. Clay is commonly used to line the bottom of holding ponds for this reason. This water retention can drown plants and rot roots during times of rain. This poor drainage can also result in shallow moisture that is susceptible to evaporation.

• Hinder Root Growth - In addition to poor drainage, this dense clay structure will also hinder root growth. It's not uncommon for plants growing in heavy clay soil to never grow outside of the hole they were originally planted in—stunting their growth both below the soil, and above. They become root bound just like plants growing in a container pot. Because the roots have a hard time penetrating the clay, plants will likely have shallow roots and need to be watered more frequently.

• Hard to work – When clay soil is wet, it becomes a heavy, sloppy mess that sticks to tools and your shoes. When it dries out it becomes very hard and can sometimes feel like you are breaking up concrete when you try to work it. If that wasn't enough, when clay dries out, the fine soil particles can become airborne, creating dust that settles just about everywhere.

• Amplifies any negative soil conditions - Clay soil is very good at storing soil elements, both good and bad. If your soil tends to be acidic, then the clay will amplify the problem. The same is true for areas with higher levels of alkalinity. Clay soil is also very good at collecting and storing destructive salts and salinity, which can literally destroy your plants.

• Lacking in beneficial bacteria, microorganisms, and organic matter - Heavy clay soil is normally lacking in healthy soil bacteria, microorganisms, and worms—the things that help plants to grow and flourish.

Can clay soil be good for your gardening?

Believe it or not, clay has some redeeming qualities. To name a few:

• Nutrient Retention - The denseness of clay soil makes it great for storing nutrients. Other soils such as sand will allow nutrients to leach away. Clay soil holds onto applied fertilizers and organic matter resulting in improved nutrition for plants.

• Moisture Retention - Clay soil is dense and compact. This attribute makes it hold water better than a sandy soil. Water does not flow away as easily, and some plants can benefit from the moisture retention.

• Less fertilizer - Clay soil is rich in a variety of minerals and nutrients that are beneficial to the growth of plants. Clay will often contain calcium, potassium, and iron in their natural forms. In addition to the natural mineral content, the soils ability to store elements can result in needing less fertilizer.

• Physical Plant Support - Clay soil provides a density that enables plants to stand stronger. Other soil types, like sand that have a looser texture, do not provide the stability of clay and can allow plants to keel over and collapse due to lack of support.

With the proper care clay soils can be very productive.

What is the ideal type of soil for a healthy lawn or garden?

When people think of good growing soil, they think of dark Loam topsoil. The dark color is the result of a surplus decomposed plant matter called humus. This humus in turn feeds and stimulates the soil’s biology that keeps the soil texture loose and provides nutrients for new plant growth.

So, what is an Ideal soil makeup? Ideal soil will typically contain:

• 45% rock particles (Sand, Silt, Clay)
• 25% water
• 25% air
• 5% organic matter(humus)

Loam soil with this makeup provides a balance of water holding capacity, drainage, and fertility.

One word of caution to people that have dense clay soils. If you mix sand into dense clay you are likely to get something more like concrete than loam.The vital element lacking in poor clay soils is humus.

What is the very best way to improve your clay soil?

If we look at the ideal soil composition again, we'll remember that good soil is:

• 45% rock particles (40%Sand, 40%Silt, 20%Clay)
• 25% water
• 25% air
• 5% organic matter(humus)

Heavy, dense clay has small soil particles that compact together and decrease the amount of air, water and organic matter in the soil. To improve your clay soil, we must change the soil makeup. Changing the size of the soil particles is not really a practical option but you can stimulate a process called Flocculation.

“Flocculation is a technical term that basically means getting the small clay particles to group into larger aggregates that make room for air, water, worms and roots.”

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You can improve this flocculation or soil structure both chemically and biologically by adding compost and amendments.

How does adding compost help break up and improve clay soil?

When you add compost to the soil the microbes and bacteria in the soil break the compost down into its basic building blocks, called humus.

Humus coats the soil particles lessening the cohesion and electrical charges that hold them together. Humus also feeds the bacteria and microorganisms; and it stimulates an increased population and activity of those good, helpful bacteria and microorganisms.

For healthy soil, we need to keep the soil at least 5% humus.

The actual restructuring of the soil is the result of a healthy population of bacteria and microorganisms. Healthy bacteria in the soil feed on the humus, and they are the active component that loosens the soil and creates air pockets for water and roots to move throughout.

Harsh conditions in the soil like herbicides and excess salts can hinder healthy biology, which slows down the composting of organic matter into humus.

How can you accelerate the humus building process of your clay soil?

Adding compost alone to break up your clay soil will help but it can take years to truly see a benefit, and it can be labor-intensive to till into the soil. Add to that any preexisting soil conditions that may interfere with the biological health of the soil like salinity or herbicides and it can be a multi-year process.

There are new soil amendments developed for the agricultural industry that can significantly accelerate this process.

RestoreClay is our biological concentrate that can help fix those conditions in your soil that can hinder the effective humus creation in the soil. It works on two fronts: first, RestoreClay will start to correct those unhealthy conditions in the soil; and second, it provides a boosting concentration of healthy bacteria and microorganisms that actively break down organic matter into humates—accelerating the composting process.

Liquid Humate is our natural soil amendment that is mined from areas that have ancient deposits of plant-based bio-matter that has been composted in the earth for thousands of years. Adding liquid humates will quickly add beneficial humus directly to your soil. Think of it as compost in a bottle. Because it is concentrated compost, it has a higher percentage of humus per volume than your traditional solid composts.

There are many additional benefits of adding RestoreClay and Liquid Humate to your lawn and garden.

This article is mainly about improving your clay soil. However, healthy soil is just a tool to grow a beautiful, healthy lawn and garden—or orchard, if you love fresh fruit that is.

In addition to being very beneficial to restoring your heavy clay soil to a life-giving healthy soil, RestoreClay and Liquid Humate will bring you impressive plant health benefits.

Get ready to enjoy the benefits of healthy soil, like these:

• Deeper, more developed root systems.
• Better fertilizer utilization and nutrient availability.
• Improved soil moisture retention
• Builds the natural immunity of the soil to help control damaging fungus and other soil issues.
• A Healthier, greener and more vibrant lawn
• Stronger, healthier, more beautiful flowers
• Better tasting fruits and vegetables
• And more.

How long does it take to amend clay soil?

While the time that it takes to improve clay soil will vary for just about every lawn and garden, there is a specific soil treatment path that works very well when followed. Your main time-determining factor will be the amount of humus that is already in your soil. An extreme, but common example, is someone that has just had a new house built, and the contractor has taken the clay soil from digging the foundation and leveled it over the yard (yes, they really do that). That soil will have less organic matter than regular top layer clay and will take longer to improve.

Think of improving heavy clay soil as an ongoing process. I find myself thinking about it like having a healthy lifestyle with a good diet and physical activity. If you stay active and eat a healthy diet you will make steady progress toward a healthy body. If you keep building the humus in the soil it will continue to improve into a productive growing soil.

Now, with that disclaimer out of the way, let's try and set some realistic expectations for you…

Amending with compost, Liquid Humate or RestoreClay will all start the improvement process. The main difference is how quickly you can expect to see results.

Applying compost will add lots of potential humus to the soil. The downside is the time it takes for the microorganisms to convert it into humus. Most gardeners say to plan on a multi-year management program.

Liquid Humate is more readily available to the soil and contains more humus per volume than compost. It will start to work faster than compost but needs to be applied more often. Most soils will show improvement within the first year if 3-4 applications are applied.

RestoreClay is the catalyst to really jump-start the humus building process. It dramatically accelerates the composting process and helps correct any unhealthy conditions in the soil. When you add 2-3 applications of RestoreClay you will see significant improvements within a growing season.

Your ideal scenario will be to use all three: Apply compost, add Liquid Humate, and apply RestoreClay.

Compost supplies a long-term supply of humus, Liquid Humates will provide short-term availability and an instant boost to the humus making processes. RestoreClay keeps the humus building process stimulated and active.

If adding compost is not a viable option like on a lawn you can still build the quantity of humus in the soil by using Liquid Humates and RestoreClay. Both are applied with a hose end sprayer.

Keeping your clay healthy and productive will need to be an ongoing process. Humus is actively consumed in new plant growth and needs to be replaced on a continual basis. Having a supply of organic matter available even on the surface and a few applications of RestoreClay will ensure this process operates effectively.

Thoughts on working and turning the soil vs leaving it undisturbed.

There is a new trend in agriculture and gardening called “no-till”. It’s a re-discovered ancient trend that’s finding new popularity in the gardening world. It is how Mother Nature has always taken care of her gardens. No-till is basically growing crops or plants year to year without disturbing the soil through tilling.

There are pros, and cons, to both tilling, and not tilling your soil.

Tilling or working the soil will enable you to get a large quantity of organic matter deeper into the soil. If you are using an amendment like RestoreClay or Liquid Humate the worked earth will allow deeper penetration of the liquid amendments allowing them to work on deeper depths of the soil.

A healthy soil structure can be delicate and repeated turning of the soil can disrupt these processes. Managing your garden by “no till” will protect the improved soil structure. If you have an area that is planted like a lawn tilling the soil is not an option. One of the major benefits of using liquid amendments is that they can also be applied to areas that cannot be tilled.

If you have heavy clay soil a combination of both practices will likely give you the best results. The first season till in a few inches of compost to get a large quantity of organic matter into the soil. After you have the first applications of compost you should be able to continue the humus building processes by covering the soil with organic matter.

Additional clay soil management best practices...

In addition to building the quantity of organic matter and humus in the soil, here are a few addition “best practices” for managing your clay soil

Avoid working the soil when wet. This one is easy because wet clay can be a literal pain in the back trying to keep mud off your shoes and tools.

Avoid compaction. Because of the tendency of the clay soil particles to compact together too much foot or vehicle traffic can undo all your hard work.

Keep the soil covered with either mulch or plants. Covered soil will retain moisture better than bare soil. Moisture keeps the biological processes active. Organic matter on the surface will still provide food for the soil bacteria and keep the humus building processes active.

Minimize salt-based fertilizers and herbicides. Excess salts can cause the soil flocculation to collapse through dispersion. Excess herbicides can disrupt healthy biological processes. Clay soil that has access to a ready supply of humus should have an abundance of soil nutrients and need less fertilizer than a sandy soil.

Amending clay soil with Gypsum.

Gypsum is a common amendment for clay soil. Gypsum is the common name for calcium sulfate. Gypsum is sometimes used in clay soils high in salinity. The calcium can help to leach the salt from the soil and lessen the dispersion. Most clay soils have adequate calcium already present and the positive effects from gypsum can be short-lived. Improving the quantity of humus in the soil will give you better results long term.

A quick word about the quality of the water you use.

As water continues to get more expensive, many people are looking for less expensive water sources. Here in Utah, some neighborhoods have access to inexpensive canal water that can be used for lawns and gardens.

This may be a regional problem but because our canal water comes from a lake it has a higher level of salinity than water from an underground aquifer. This happens because the water in the reservoir or lake evaporates and leaves the salts behind. Over time these salinity levels can become a stressor for plants. Some plants can handle salinity better than others. If you start to see plant leaves start to brown around the edges it could be a sign of high levels of salinity.

Having salt in your soil will also cause dispersion, a process that can quickly cause the amended clay to turn back into a hard, dense soil.

Both RestoreClay and Liquid Humate, can tie up those salts, and help leach them from the soil, but if more salt is being added with every watering, then you will need to keep up with your soil maintenance practices.

In summary…

Remember, if you're not sure what type of soil is in your yard you can always reference the helpful indicators previously outlined in this article. If your soil is hard when it's dry, and it doesn't crumble easily when you squeeze the soil in your hand, then that can indicate a certain amount of clay particles in your soil.
Clay soil tends to amplify your other negative soil conditions because clay soil is quite good at storing soil elements, even the bad elements. So, bear in mind that if your soil tends to be acidic, then having clay as part of your soil will amplify the problems you are facing when trying to grow that amazing lawn and garden.

If we look at the ideal soil composition again, then we remind ourselves that we want to keep our healthy soil at about 45% rock particles, 25% water, 25% air, and 5% organic matter—aka humus. Heavy, dense clay has small soil particles that compact together and decrease the amount of air, water and organic matter in the soil—ruining our chances at having the lawn and garden that we truly want: lush, full, green, vibrant, and full of beauty.

When adding compost to your soil it helps break to up and improve clay soil because the microbes and bacteria in the soil break the compost down into its basic building blocks, called humus. However, adding compost alone isn’t going to give your clay soil everything that it needs to become healthy life-giving soil.

Amending your soil isn’t going to happen overnight, or even with a single application of any amendment product. It’s going to take time, and the time that it takes to improve clay soil will vary among all lawns and gardens—but, there is a specific soil treatment path that works very well when followed. Ask us about it. We would love to show how it’s done.

But, how & where do you start your soil amendment process?