Clay is one of the most challenging types of soil any gardener can work with. Soil mostly made of clay isn’t your average soil, as it can be tricky to handle, whether dry or wet.
However, clay soil has a few welcome benefits to help plant growth and maintenance. This is why many people go through the trouble of using it, knowing how strenuous it can get.
If you’re curious about how to amend clay soil, you’re in the right place. In this article, we’ll go into further detail about how it works, its advantages and disadvantages, and what grows in it.
Let’s get started.
What Is Clay Soil?
Clay soil is made up of complex structured particles at the atomic level. Since it’s compact, there’s not much space available between the tiny minerals, and it has a low drainage capability.
Most parts of the U.S. have clay soil, which makes it troublesome for flower and vegetable gardeners. If you’re unsure of the type of soil you’re working with, you can run a few DIY tests to find out.
You can also determine if it’s clay soil by observing water behavior. If the water tends to puddle rather than soak in, you’re likely looking at clay soil. If it’s too tricky to figure out, here are some other tests you can try:
- Squeeze test: Checking if the soil keeps its form when you apply pressure
- Percolation: Measuring how long it takes for the soil to drain water
- Worm test: Counting how many earthworms are visible in a dug-up section
- pH test: Measuring the soil’s pH value using a pH testing kit
In most cases, it will be noticeable if the soil is mostly made of clay. Clay soil is usually quite sticky and rolls like plasticine, especially when wet.
Clay Soil pH
A clay soil’s pH level usually ranges from 8 to 10, depending on what materials it contains. For instance, red clay soil can be rich in iron oxide, so its pH can go below 7, making it acidic.
If you have a pH testing kit, you can easily measure the pH level of your clay soil. This will help determine which types of plants you can grow in it.
If you’re opting to use clay soil for its benefits, you can always adjust the pH levels by amending it.
Why Amend Clay Soil
Clay soil needs amendment to become sustainable for plants. The original state of clay soil is too harsh, resulting in an unhealthy environment for plants to grow.
It’s also tricky to work with clay soil without the necessary amendments.
The ideal way to work with clay soil is when it’s extra wet or extra dry. Working between these conditions may cause it to cling to your shovel, making digging highly difficult.
How to Amend Clay Soil
The first thing you need to do to amend clay soil is to determine its moisture level.
Adding organic materials is the most recommended method to amend and improve clay soil. To prepare your clay soil for amending:
- Examine the clay soil’s moisture level and ensure it’s either extra wet or extra dry.
- Sculpt the land with alternating peaks and valleys for water management.
- Create air pockets in the clay soil for better drainage, reduced compaction, and to invite soil microorganisms.
- Mix in your preferred organic materials thoroughly in the clay soil.
Combining air pockets with organic materials will attract microorganisms, such as insects, earthworms, and other bacteria and fungi. The organic materials you add will serve as their food.
Organic Materials For Clay Soil
In the decomposition process, the microorganisms will convert the organic materials into soil nutrients. This, in turn, will give your plants a readily available source of food to aid their growth.
The organic materials you can use to amend clay soil include:
- Homemade compost
- Worm castings
- Sawdust
- Leaf mold
- Peat moss
- Bark
- Manure (green plant matter, livestock, etc.)
The ideal amount of organic materials to use should be around six to eight inches worth of layer per garden bed.
Maintaining Clay Soil
The common misconception people have with clay soil is that you have to mix it with its opposing type of mineral, which is sand.
However, this isn’t necessarily the case, as directly adding sand to clay can result in the soil having some concrete-like properties.
It’s best to stick with the recommended preparation and organic materials when amending the clay soil.
Take note that amending isn’t the only thing to consider for clay soils. You also have to do a consistent maintenance check every once in a while.
Here’s a checklist of the maintenance needed to preserve your clay soil garden:
- Collect soil samples and run a pH test every change of season to know if there are any pH issues or nutrient deficiencies.
- Continue adding organic matter or soil amendments to the clay soil every season.
- Take advantage of the fall season by not removing dead leaves and other plant materials for added mulch.
Advantages of Clay Soil
As much as clay soil needs extra effort to till, maintain, amend, and use, it comes with a few handy advantages for plant growth.
Here are some of the notable benefits of using clay soil for plants:
- Moisture retention: Clay soil has ample resistance to drought due to its ability to retain water and moisture.
- Nutrient storage capacity: Similar to how it holds on to water well, it also does the same to keep nutrients readily available for plants.
- Resistance to erosion: Due to the density of clay soil, it helps minimize the risks of erosion.
Disadvantages of Clay Soil
The use of clay soil isn’t universal, meaning it won’t work with every type of plant. Therefore, its usage comes with some disadvantages that won’t sit well with certain plants.
These are the cons to consider before deciding to use clay soil:
- Lack of drainage capability: The downside of water retention is that plants can also become prone to flooding or drowning.
- Takes a while to adjust to different temperatures: Since retention is a key feature in clay soils, this also results in slow temperature adjustments, which can stunt the growth of plants.
- Tendency to have high pH levels: Higher pH levels in soil can cause wilted leaves and stunted growth, so you have to properly amend clay soil first to adjust its pH level.
What Grows in Clay Soil?
Once you break through the challenging conditions of handling clay soil, you’ll have the option to grow a variety of plants that thrive well in it.
Since clay soil retains water and nutrients quite well, your plants will grow better and in full bloom.
You’d be surprised how even at least 1% to 5% of clay presence in your soil can make a huge difference in boosting plant growth.
On that note, here are ten of the best plants to grow in clay soil:
- Bearded Iris (Iris germanica)
- Blazing Star (Liatris spicata)
- Big Bluestem(Andropogon gerardii)
- Wild Bee Balm (Monarda fistulosa)
- Arkansas Blue Star (Amsonia hubrichtii)
- Autumn Joy Sedum (Hylotelephium ‘Autumn Joy’)
- Prairie Blazing Star (Liatris pycnostachya)
- Canadian Wild Rye (Elymus canadensis)
- New York Ironweed (Vernonia noveboracensis)
- Fountain grass (Pennisetum alopecuroides)
Remember that the use of clay soil is only an additional benefit to plant growth. Plants that can tolerate clay soil still need other necessities to grow and survive.
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Clay Soil FAQs
Is Clay Soil Good For Plants?
Clay soil has a lot of beneficial properties that can sustain certain plants better. However, not all plants are capable of tolerating the conditions present in clay soil.
Clay soils are also good at securing plant roots for added protection against extreme temperatures. At the same time, some plants can also die easily from drowning since clay soil has very little drainage capabilities.
Why Is Clay Soil Important?
Nutrient retention plays a vital role in enabling and sustaining vegetation growth in a certain type of land. For this reason, we can see how useful clay soil can be in providing plants with their much-needed nutrients.
Clay soil also provides a sustainable environment that’s good for attracting microorganisms. Thanks to the presence of microorganisms, organic material in the soil will be broken down and turned into healthy plant food.
Can Flowers Bloom in Clay Soil?
Most of the plants that thrive in clay soil are capable of growing in full bloom with colorful flowers.
However, it’s worth noting that clay soil plants have different needs, depending on their type. Some plants may need a bit of shade, while others call for bright and direct sunlight exposure to bloom.
Final Thoughts
The key to handling clay soil is knowing what you’re dealing with. After running a test or two, you can adjust the soil’s conditions to fit your gardening needs better.
While most gardeners tend to fear clay soil, it has many practical applications that need some careful tweaking. As long as you’re prepared to work extra in amending and maintaining clay soil, your plants can go a long way.