How To Improve Clay Soil for Gardening

If you’re looking for tips on how to improve clay soil, check out these frustration-free ideas!

Here in the Cariboo region of British Columbia, we have clay based soil in our lawn that we are always trying to amend. I had never seen heavy clay soil before we moved here.

Over time we learned how to improve clay soil. Here’s how we were able to improve soil fertility in our home garden.

How to Improve Clay Soil

Before I share how to fix your soil, here is a bit of history of what our soil (and first time garden) was like when we moved here to the Valley.

We came here at the beginning of June and maybe 3 days later, we had our first garden in. We planted mostly potatoes which are good for breaking up the soil.

This is something to keep in mind if you are breaking in a first year garden with hard, lousy soil. Plant potatoes! Plant lots of potatoes.

Head on over here if you want to learn how to grow potatoes.

I didn’t think we would have much of a harvest that year. But the garden did better than we thought it would and we grew some beets,  peas, salad greens and even pole beans.

 

A great resource for homesteading and gardening was Carla Emery’s book Encyclopedia of Country Living.

I am still often looking something up in this awesome book. It is full of widespread information about different aspects of homesteading.

This book covers everything I needed to know about growing food, preserving food and even raising animals. There is lots of information about the importance of building your soil.

 

Why is Clay Hard to Grow In?

Solid clumps of clay are hard to garden in! Because of the shape of clay particles (flat and condensed instead of round, as something like sand, silt, or loam might be), compaction is a large problem, especially when wet or under any kind of pressure.

A garden bed full of heavy clay soil is like mud when there’s been a good rainfall. Then, when it does dry out, it is like concrete.

This prevents things like air, moisture, minerals, and nutrients from filtering in and out, which is a surefire way to stunt any plant growth.

Great ways to promote better drainage and aeration in clay soil is by top dressing with any (or a combination) of these components:

• pine bark
• gypsum
• mulch
• composted leaves
• grass clippings

 

 

How to Amend Clay Soil for Vegetable Gardens

There are a number of soil amendments you can make to enrich your clay and loosen it up. Use aged manure or compost.

Using Cover Crops to Improve Soil

Growing some cover crops that are rich in the nutrients your soil needs is a great way to use organic matter to improve soil quality. Getting a garden soil test is a great first step.

Great choices for cover crops include:

• Buckwheat
• Fall Rye (or Winter Rye)
• Clovers, both red and white
• Alfalfa

Grow Buckwheat

We use buckwheat as a form of green manure and you can read about how we grow and use it. It works very well for us as we have a shorter gardening season (Canada Zone 3) and it matures so quickly.

Buckwheat grows especially well in moist, cool climates and cold areas. It’s also a good grain choice if you have poor soil, especially if it’s dense clay, because the roots break up the clay and make it loose.

A real advantage to Buckwheat is we use it to cover areas from early harvested vegetables. So, it’s a cover crop that we can grow in a few weeks, let it set seed and use as Buckwheat flour. Or turn under the entire plant to add nutrients.

Just don’t let it set seed and then dig it under or you’ll have  a lot of Buckwheat growing in that spot.

Grow Rye Grass

We have always used fall rye as a green manure for the garden. We sow it in the fall and in spring, once growth starts again, we work it in to the soil by tilling.

Some people are opposed to tillage on such heavy clay, but we are adding lots of air and other materials like the green manures. It doesn’t take long and you will see the soil become lighter with a good ability to drain properly.

If you don’t have a tiller, you can use a shovel or a garden fork instead. Dig deep and turn over the entire root system. Leave the stems and leaves (full of plant nutrients) to decompose further into the soil.

This has been a big help for us and we also use it in harvested areas of the garden during the gardening season. It grows quickly, which is another bonus.

If you grow Fall Rye just don’t let it get to tall before cutting. The stalks can get tough and that makes it difficult to cut down. Cut it before it gets over 2 feet tall; there are plenty of nutrients in plants that size.

Other Soil Building Organic Materials to Improve Bad Soil

• Well aged manure, including chicken, pig, cow and horse.
• Well aged kitchen compost.
• Old bedding from animal pens is done as well. The hay/straw breaks down and adds to allow air into the soil.

 

We get wonderful harvests from our gardens. Vegetables, berries, perennial veggies like asparagus and rhubarb.

We grow enough to fill our cold room and eat lots of great fresh food!

Each year the garden soil has improved and we can tell by the texture. It’s lighter and fluffier than last year, and last year was better than the year before.

The more compost, green manure, straw etc. we add – the better the soil will become. And this has to be an ongoing project; otherwise, the good soil will again get depleted.

Another Benefit of Using Cover Crops

Using some type of plant material to help improve your soil, has another benefit. That is keeping your soil covered. Try to not leave soil bare and exposed to the elements; erosion will easily happen and whatever is good in your top soil will be gone.

Keep your soil covered (as in fully planted) and it will help not only the soil ph but will keep any soil microorganisms in better health. 

If you can’t seed a cover crop for whatever reason, consider covering exposed parts of your garden with a layer of straw.

 

Homesteading Articles You’ll Love

• Want to learn about canning your own food? Read about how to use a pressure canner to can meats and also how to can fish.
• Water bath canning is the easiest way to start to learn how to home can. 
• Here’s how to build a Greenhouse – we extended our growing season for under $200!
• Learn more about rye grass benefits.

 

So now that you know how to improve clay soil, hopefully you can use these tips to lighten your soil and get better garden harvests.

 

 

 

originally published 2011; last updated April 2025