Clay soil is cumbersome for just about any gardener. And it can make your dreams of fresh produce seem impossible. But, with a little bit of work you can improve clay soil and turn it into the well-draining, beautiful loamy soil a gardeners dreams are made of.
A lot of us have to deal with clay soil. It’s pretty prevalent in most areas. Our entire property is full of it. Years of mono-cropping and then grading the land to build a house pretty much made our soil a hard rock-like mass that doesn’t even like to grow grass.
When we created our first garden here, it left a lot to be desired. If it rained even a tiny bit, the water would simply puddle up and sit on the surface because the soil was so hard and compacted it couldn’t drain. It was more than a little discouraging.
Thankfully, with a little bit of work and a few simple additions, we got our soil on track and now it’s the kind of soil that gardener’s dream of. Rich, loamy soil instead of the dirt we inherited. And I’m excited to share with you how we did it so you can fix yours, too.
But, before that, I wanted to talk a little bit about the good and bad that is clay soil. (Yes, it does have some advantages).
Advantages of Clay Soil
Believe it or not… clay soil, as difficult as it may seem to a gardener, does have some advantages. Since it is so dense, it retains moisture very well (if it can actually drain off and not puddle is another story, entirely).
Clay soil also tends to hold on to its nutrients which can be advantageous over the nice, loose soil we enjoy gardening in.
It will also grow some plants fairly well including trees with deep root systems (anyone want an oak tree??) and even some flowers and herbs like black eyed susans and echinacea.
Disadvantages of Clay Soil
Of course there are disadvantages to clay soil. Probably more than there are advantages. Clay soil just kinda sucks the gardening life right out of ya…. For one, it doesn’t drain very well. When we first uncovered our current garden spot, it would have water puddled and standing in it in no time flat.
Another disadvantage of this pesky soil type is it takes seemingly forever to warm up in the spring. Everyone will be planting their gardens and we still can’t get a shovel to break through the top. Not that it’s much easier when the soil is thawed, but still.
It also compacts incredibly easily. So, walking on it? Yeah… you thought you had decent soil after you tilled it up only to discover as soon as anything steps on it, it’s a hard, compacted rock that doesn’t drain.
Improving Clay Soil
Thankfully, clay soil can be improved upon and fairly easily. While it does take work and a bit of time, the work you put in will instantly improve your soil and allow you to grow those delicious veggies a lot more easily without delay. You do not have to do everything I suggest here, however, the more you do, the more amazing your soil will be.
Improve the Entire Bed At Once
I’ve heard of people saying that they only amend each hole they dig to plant in. Well, that works in theory. You add the soil/compost mixture once you backfill. But, the roots of the plant you just planted are going to have an incredibly difficult time breaking through the clay that surrounds them.
That being said, it is best to prepare your garden bed and begin improving it all at one time. So, pick your spot and get started so we don’t have a bunch of root bound plants in a month or two.
Tilling & Aerating
Aerating your clay soil is essential to break it up and improve drainage. We aerate our soil twice a year. We till in organic matter in the fall with a rototiller and simply use a broadfork to poke holes and move the soil a little in the spring before adding more well-aged compost to the top and planting.
There is a strong pull to no-till gardening and it can be incredibly beneficial. Over-tilling is a concern and can lead to further compaction and more problems than any gardener wants. But, we do gently till every fall. If you don’t want to till it, you don’t have to. Simply take a broadfork or similar tool to poke holes and then add your organic material on top. It will work itself in over time through the aeration holes you created.
Adding organic material to any garden is essential to soil health, but it significantly improves clay soil almost immediately. I’m always amazed when we throw a nice, thick layer of compost over the compacted soil we always begin with how different the composition is when we are finished. It’s workable, well drained, nice, loamy soil that I can dig into with my hands and not feel like I need a chainsaw to break the surface.
Organic material needs to be added in copious amounts in the beginning. Around 6″ of material should be added as soon as the soil is aerated so it can wash down into the newly created holes and work its magic to soften the soil.
The following organic materials all work really well to help improve your soil.
Your own compost is a fantastic addition to improve clay soil. Make sure it is well-aged and if you composted it yourself… even better. If you’re applying composted manure, it is essential that you ask questions and insure that the animal never ate anything that was sprayed. If the hay they consumed was sprayed, don’t put it on your garden. You’re just asking for headaches and dead plants.
You can put manure directly on your garden bed and allow it to work in as long as you have at least 3 months before you are planting anything. Same thing, you’ll want to make sure that the animal never consumed anything that was sprayed. Or… well, you’ll probably end up with a lackluster gardening season.
Make sure that the soil isn’t drenched when applying manure and make sure there isn’t any heavy rain in the forecast. This helps decrease runoff so that the nutrients say in your soil and out of waterways and other places we don’t want the manure to wind up.
Worms are pretty amazing and their castings are a great addition to your garden. They are high in minerals and nitrogen and the richest fertilizer we are aware of. You can create your own with vermicomposting, or you can purchase them in bags.
If you’ve never heard of leaf mold, you aren’t alone. I had never heard the term used until a couple years ago. What it is is leaves that have been left to decompose over a few years time. The result is some amazing black gold for you to add to your garden.
We actually picked up several tons of leaf mold this year because we certainly didn’t have enough compost to add on our own and I’m leery of adding compost from elsewhere. This stuff worked amazingly well and transformed our expansion into workable, beautiful, loamy soil in a matter of the couple of hours it took to put it on.
Utilize A Cover Crop
Cover crops are great to help amend your clay soil. They’re pretty simple to utilize, too. You generally just spread them down like you’re planting grass and wait.
Cover crops work to enrich your soil by helping incorporate the amendments you add when they’re rooting in. They also help add nutrients and prevent weeds and erosion. There are several crops to choose from, depending on your climate and what you’re looking for.
Adding cover crops in the fall is what most typically do, but you can add summer cover crops, especially in bare places, as well. We planted a cover crop and were amazed at how much healthier our soil was afterwards. They really do an amazing job at improving soil structure.
If you’re not going to put down a cover crop, you should add a good layer of mulch to help improve the soil and protect it from erosion. Leaving the soil bare will just cause it to compact again. There are lots of different materials you can utilize to mulch your garden. And in the fall some are completely free.
Shredded leaves make an amazing mulch for your garden, so if you have some, add some. They work just the same way in the forest as they will for your garden. To shred them, simply run them over with a lawn mower.
Straw is another great mulch and is our go-to because we don’t have a ton of leaves available (yet). However, use straw with caution. You need to make sure it hasn’t been sprayed (just like the food the livestock ate). A lot of grass crops are sprayed now and they will wreak havoc on your garden. So, the moral of the story is… know your farmer and ask questions.
You’ll want to mulch lightly before the wet conditions of winter but a little heavier if it’s dry and hot.
What Not to Do
Now you know what to do. However, there are some things you’re going to want to avoid. I’ve laid them out for you here.
Walk On It
I find it best to make permanent pathways in your garden. This helps avoid walking on areas you should be planting plants in. To make permanent pathways, you’ll want to select the paths of least resistance knowing full-well that everyone is going to take the short distance whether it’s where your intended path is or not. You can line them with stone, lay mulch down, or whatever you need to do.
Walking on the garden will quickly compact it back into the compacted clay that you just spent all of that time improving. So, lay out some paths and try not to make your planting beds too large (2-3 feet wide) so you can reach all the way.
There is a common misconception that adding sand to clay soil will improve it. This will not work. Instead of improving it, you’ll probably wind up with a bed of concrete-like material. Worms won’t be able to live in it and neither will any plant life. So, steer clear of the sand and utilize some of the additions I mentioned above.
Improving clay soil isn’t difficult. But it does require time and hard work. However, your efforts will pay off in multiple ways when you’re able to pick that fresh produce straight out of the garden and place it on your dinner plate. The feeling of pride it gives, the sense of accomplishment… it makes it all worthwhile. Every season you’ll want to aerate, add a fresh layer of organic material and add some mulch, but every year it will get easier and easier and seem like it requires less and less work.