Starting A Garden In Clay Soil: Step By Step Guide


Starting a garden in any environment can be quite a lot of work, but if you have clay soil, you will need quite a bit more work than expected. After a few hours of some research and handiwork, the good news is that you have soil that will be ready to plant and grow healthy plants.

You will likely be able to harvest quite a few flowers, veggies, or fruits, depending on what you plant in your first year. However, the issue with the first harvest year is that the soil is still improving and isn’t quite where you need it to be for plants that will flourish.

Identify Soil Make-Up

It is often that many people believe that they have clay soil, when in fact, they have some other type. You want to identify your soil by noticing a few key features of clay soil.

  • Crusts over and cracks in dry weather
  • Sticks to garden tools and shoes like glue
  • Water puddles on clay rather than soaking in
  • Sticks together like a soft concrete

If these are characteristics of your soil, then, unfortunately, you have clay. However, this can be fixed with some work. It will help you to know how heavy and thick your clay is; then you can figure out how to go about fixing it.

Any soil that is made up of over 50% of clay particles is considered heavy clay. Chances are, if you are noticing these characteristics easily, you have heavy clay.

A quick test that you can do that will help your figure out what type of soil you have is:

  • Add water to a small amount of soil and roll into a ball.
  • Start kneading it with your thumb and finger, making it a ribbon-like shape.
  • If your ribbon is less than 1 inch before it breaks, you have loam soil.
  • If your ribbon is between 1 and 2 inches long when it breaks, you have clay loam.
  • If your ribbon is 2 inches or greater before it breaks, you have clay.

Here’s a helpful walk-through video about soil types:

Loam Soil

If you have loam soil in your garden, you have a lot less work cut out for you than you originally believed. Loam is a good mix of clay, silt, and sand, which allows for plants’ good growth. This also means you won’t have to work so hard to add nutrients and get the soil ready for root growth.

The most you may have to do is add some compost, rough up the top layers of dirt and keep it mulched.

Clay-Loam Soil

Clay-loam soil is a fantastic soil to plant and grow a garden in. The clay that is present in the soil helps keep in moisture and nutrients, while the loam allows plants to grow roots without having to work too hard.

The most you may have to do when improving this soil is tilling it and adding compost to give a good nutrient base. After that, you will be able to plant most anything and receive thriving plants.

Clay Soil

Clay soil is, of course, pure clay. This type of soil needs quite a bit of work to get ready for a garden setting. Without trying to fix the soil, your plants will not have enough nutrients to stay alive, and they won’t be able to grow roots through the compacted soil.

You have to layer organic material and mix it in several times before your planting season to get your soil ready to grow anything. Even after doing this, it could be a few years before your plants truly thrive in your soil.

(Source: Improving Soils, Plant and Soil Science)

Remove Existing Plants

If you are improving an existing garden area, you may have some plants that managed to grow in the area, but they probably aren’t thriving. You want to remove these plants carefully so that you don’t damage any of their roots.

Once you get the plants out, you can replant them into the soil once you improve it. These plants should be examples of how unhealthy your soil was because you will watch them thrive instead of just survive after being replanted.

If you don’t want to replant any of the plants you already have planted, you can leave them there and fill them up with your soil to use as extra organic matter. You can also take plants from other areas in your yard and replant them in your newly improved soil to help them have healthier soil to grow in.

Layer Organic Matter On Top

Organic matter is defined as Dead animal or plant leftovers that are decomposing. In reality, you can use any of the following for organic matter:

  • Grass clippings (with no chemical treatments)
  • Shredded dead leaves
  • Compost
  • Manure.

Once you decide what to use as compost, whether it be one single product or a mix, you want to spread 6-8 inches of it on top of your existing soil. Ensuring you have enough organic matter is essential to improving your soil as much as it can be improved.

You can also use organic matter as a mulch in the offseason. This will help remove the possibility of soil washout as keep your soil healthy and ready for your next harvest.

(Source: Dictionary, The Spruce)

Mix Organic Matter Into Soil

Then the next step requires a bit of manual labor because you have to mix in the organic matter within 6-12 inches of your soil. How deep you go matters depending on if you are planting root vegetables or other plants that need to be deeper than 6 inches.

  • You can use a tiller if you choose, but it can cause the soil under it to become more compacted and more problematic for plants to root through.
  • If the soil is generously moist, you can probably use a tiller for the first mixing.

The other ways to mix the organic matter in are by using a shovel and your hands or using an aerator and working backward, so you don’t step on the loose soil. Either one of these works well and provides ample space to allow water deeper into the ground.

Fix Entire Garden Plot

One thing that can mess up your soil is if you try and cut corners by only fixing the spots you want to plant in. This equals out to less work in the beginning but can severely impact your plants.

If you only fix the planting holes that you need, you are essentially making an in-ground flower pot. This will keep your plants happy for a short time, but eventually, the soil around the planting hole will start to steal the nutrients out of the healthy soil.

Your plants will also run out of room to grow and thrive if you don’t fix the entire garden plot. The clay around the hole you created will not allow for root growth, and your plants will be so root bound that they will not be able to manage the development or production of flowers or food.

(Source: Grow Veg, Tenth Acre Farm)

Plant Cover Crops

The first thing you want to plant in your newly fixed soil is a cover crop. This crop will give roots that help break through the soil and add oxygen and nutrients to it that will help other things grow. You will want to plant cover crops in fall and late spring to prepare your garden for your harvest crops.

  • If you plant a harvest crop in the fall, it provides an excellent area for insects to breed and live, which can help your soil and future plants grow.
  • Even if you live in a climate that has cold enough weather to kill off your harvest crop, you will still reap the benefits of a harvest crop.

When you plant a cover crop in late spring, you want to focus on flowering plants to provide pollinators for your garden. The bees will help to pollinate your harvest plants and provide you with more fruit and veggies.

The cover crops from spring will also help fill the empty spaces in your garden plot and help hold the soil together with their roots to prevent washout from rain. Some of your crops may not be beneficial by the time summer hits, and you can break those up with a shovel and plant on top of the organic matter they leave behind.

No matter what cover crop, or plants you choose, allowing things to grow in your soil before you plant your harvest crops will exponentially increase your plant’s output and lifespan.

Plant Clay-Friendly Plants

The first year you choose to play any type of plant in your garden of freshly improved soil, you will want to pick plants that are more clay friendly. In your first year of planting in your newly fixed soil, it’s best not to expect a full harvest or fully thriving plants.

We have a full article about the Top 20 Plants That Will Thrive In Clay Soil but here’s the short list.

Some vegetable plants that are considered clay-friendly are:

  • Lettuce
  • Chard
  • Snap beans
  • Broccoli
  • Brussel Sprouts
  • Cabbage

Some late-spring cover crop plants are:

  • Black-eyed Susans
  • Phlox
  • Indian Pink
  • Cardinal Flower

While this may not be what you fully desired to plant in your garden plot, the first year you grow anything, it is crucial to plant as much as possible. This will help your soil hold nutrients and provide more organic material for your plants to grow from.

Here’s a quick video talking about clay friendly plants:

Now, you can plant whatever you desire in your garden, but these recommendations are purely based upon people who have already done the work on the garden and noticed what grows well and what doesn’t. You may find that in your region, different plants do even better.

(Source: American Meadows, Fine Gardening)

Mulch

If you don’t desire to plant a cover crop, you can mulch regularly throughout the offseason to keep your soil nutrient-filled and loose. You want to mulch with organic material to ensure that your soil stays healthy and ready for your planting season.

When your weather is dry and hot, you want to do heavy layers of mulch to help protect the soil and keep moisture in. When your weather is rainy, you want to put a thin mulch layer down to protect the ground from washout, but not too much that it can grow mold or fungus.

Stay Out Of The Garden Plots

The last thing you want to do after you put so much work into your garden is to step in it or apply too much pressure to the surface. This can compact the soil and possibly put you right back where you started if it is done enough.

You want to try and make your garden plots small enough to reach them from the sides, or plant in rows with spaces that are big enough to walk in between them. As much as you can stay out of the soil that you want to plant is, the better it will be for your plants.

Yearly Soil Testing

Every year, you will want to take an oil sample and have it tested for several things, such as:

  • Establishing a baseline for nutrient levels
  • Can give recommendations for nutrient additions
  • Helps determine PH levels which are needed for specific plants
  • Can help with being certified for certain selling requirements
  • Can give notice of toxicities in soil

Being able to know this information about your soil will change so much about how you plant and harvest. Knowing precisely what your soil needs or what is wrong with it will help you fix it and understand why your plants are not producing how they should.

(Source: Catalog Soil, Gardening Know-How)

Things To Know About Clay Soil

There are pieces of advice that people share and pass on that may not be the most accurate. Just because it worked once or was something their family always did doesn’t mean it’s the best way or even the right way to fix things. You want to be able to distinguish the good advice from the things you shouldn’t ever do.

Don’t Mix in Sand

There is a misconception when it comes to fixing soil that you can mix some of the opposite types in, and it will equal each other out. However, this is severely incorrect; adding sand to your clay soil will only cause more problems.

When you mix sand into clay soil, it mixes and creates a texture very close to concrete. Once you mix sand into it, it will be almost impossible to get anything to grow because the roots won’t have anywhere to go and won’t be able to get through the tough soil.

Don’t Dig Up Wet Clay

It is often believed that wet clay is easier to dig up over dry clay; however, this is incorrect. While the initial work may be easier, as you dig deeper, it will be harder because the extra moisture causes more compaction in the soil.

It is best to dig in at your soil when it isn’t soaking wet but before it cracks because it is so dry. This is the easiest way to mix in organic compounds without causing extra compaction. If your soil is too compacted, while it will be hard for you to dig up, it will be even more challenging for your plants to take root and get the nutrients that they need.

Different Uses For Clay

If you have far more clay that you can use for your garden, it can be taken from other areas and repurposed in your garden for more than just growing plants.

You can create sun-dried clay bricks to help define the borders of your garden. You simply take clay and form it into bricks and leave it in the sun to dry for a few days.

You can also use it to help reduce flooding by creating barriers that will repel water on the outside of your garden. This will allow water to get in from the rain but won’t let extra water come in from your yard and washout your soil.

If you need a way to channel the water throughout your garden and drain it, you can create tunnels to do that with the clay as well. Clay naturally repels water, so creating tunnels through your garden will allow some water to be absorbed without allowing too much to sit in puddles.

(Source: Do It Yourself, Playtunnel Gardening)

Final Thoughts

If you have clay soil, you might believe that you won’t ever grow anything worthwhile in your garden. However, the good news is, you can fix your soil and produce thriving plants on a yearly basis with just a few steps.

If you are willing to put in a bit of handiwork and some research, chances are, you can fix your soil, no matter how impossible it may seem.

Robert Sampson

I'm Robert Sampson and I live in Colorado where I spend a lot of time in the backyard with my family either grilling, playing games and sports, or working on a project to make our backyard a better place to be.

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