What to do with Clay Soil

If you can make a ball out of your soil that stays, you've got Clay Soil!

A clay baseball made from the soil in our yard. This ball actually stayed together well enough to throw it and have the dog fetch it and bring it back with only teeth marks to show for the adventure!

Have you ever wondered if the soil in you area has a lot of clay?  I have read online about several tests you can perform to figure out what is in your soil.  Though I have tried them (my favorite involves a mason jar and a scoop of soil), I have settled on the simplest of all: moisten some of your soil well, or just wait until a day after it rains.  Dig up a scoop and try to make a ball out of it.  If you can make yours look like the one in the picture on the left, congratulations – you have some serious clay content in your soil!

So, you have clay soil.  What now?  Some of the problems with high clay content are that it is so dense and heavy that water, plant roots and even your shovel have a hard time getting through it.  Once water has managed to permeate the clay, it takes a long time to seep away.  As a result, plants grown in clay tend to suffer from drowning, suffocating and rot more often than in loamy soils.

There are some benefits to clay soils, though.  The nutrient levels in clay are quite high.  Depending on where you live and what kind of clay you have, you will find that the PH of the soil is naturally beneficial a certain segment of plants.  Here in the Washington D.C. region, our red clay is particularly acidic which is nice for plants such as hydrangea and blueberries.  That said, you will need to improve the drainage and friability of you clay.

Ways to Improve You Clay Soil:

  • Add Compost:  If you practice composting, this is an excellent addition to the soil.  Compost ‘lighten’ the clay, improving the drainage quality and availability organic matter and air for your plants.  I have found that all of the compost I could possibly produce would not be enough to help all of the soil we garden.  I have found a good source of vegetable compost (versus compost derived from sewage) and buy it by the cubic yard, which is a small pickup truck full.  It costs about $30 per yard at Virginia Ground Covers.  We have had good results in about a half and half mixture of compost to clay along with the other additions yet to be mentioned.
  • Add Peat Moss: Peat Moss improves both the clay’s water retention and drainage qualities as well as further ‘lightening’ the soil so that plant roots can successfully penetrate the soil in search of nutrients.  I mix in two 3-cubic-foot bales of peat into each cubic yard of compost in amending our clay.  Peat is running about $10 per bale at Home Improvement stores.
  • Add Coarse Builder’s Sand:  Coarse sand will further improve the drainage of clay soils.  We have only added sand to our blackberry and raspberry patches, finding that the volume of peat and compost is enough to work well in our other gardens.  Coarse builder’s sand is readily available and inexpensive at your local Home Improvement store. 
  • Add Gypsum:  Gypsum is sold by many different brand names for the purpose of ‘breaking’ your hardened clay soils, creating an environment more suitable for roots to grow and spread.  The results of adding gypsum are due to a chemical reaction with the clay and are temporary.  We have found it useful to add gypsum to new garden beds when we fist mix in our other amendments.  The ‘breaking’ effects help to crumble the clay into smaller bits and integrate more thoroughly.
  • Adjust your PH:  You will need to test your soil in order to adjust your PH properly.  I recommend having your local Extension Office complete the test versus buying a test kit at the store.  The Extension Office performs a much more controlled test and achieves very accurate results.  You will also need to know what types of plants you will be growing in order to adjust your PH to the correct level.  I grew up cleaning out the fireplace ashes and tossing them around the Lilac bushes to ‘sweeten’ the soil, as my father calls it.

With the need for so many additions to our soil, we build raised beds for our gardening.  With some guides to gardening, it is suggested that in raising the beds you might as well simply fill them with good garden soil and leave the existing clay alone.  I am very careful to turn up the clay and mix it in to the amendments.  Why?  My wife asked me the same thing.  There are several reasons:

Our native clay have mineral resources and nutrients that I would otherwise have to add, creating more effort and expenditure.  Clay itself is has excellent water retention properties which are a welcome addition to any garden, in moderation.  Working the amendments into the clay results in raised beds that are cultivated 6 to 8 inches below ground level, so our 12 inch tall raised beds are actually 18 to 20 inches deep in terms of perfect plant growing soil.  Lastly, our clay represents here.  Were I to grow my vegetables in the same purchased soil mixture as someone a thousand miles away, I might as well have grown them anywhere.  I am attached to tasting a sense of Terroir in our food.  There is more to Local Food than where it is produced.  A producer of hydroponic lettuces just down the street is definitely local in that the produce has not been trucked a thousand miles (which I am thankful for), yet that same lettuce has no sense of place in the respect that it could have been grow anywhere.  I’ll still buy the locally produced hydroponic lettuce over the heads grown half way around the world, and I’ll feel good about it!  And I will still expend the extra effort required to churn our clay up into the compost of our raised beds.

Please share your adventures in working with clay soil.  We’ve all taken different approaches and have differing results in trying to grow a successful garden in the hard-packed clay.  Feel free to ask for some help, too!  I’m sure that if I cannot help, there are many readers who have struggled with similar issues and would love to help.

Cheers!

~The Suburban Hayseed.

 

Simple, Affordable and Attractive Raised Beds

A Truck as a Raised Bed!

Now that's a raised bed!

Building raised beds for your garden – whether for vegetables or flowers – can be as complicated or as simple as you like.  From rustic railroad ties to cinder blocks to decorative landscaping stones, whatever you feel fits into your landscaping theme can be used to hold in a few more inches of amended, delicious soil to cultivate your crop.

Our adventure into creating raised beds began in order to get our plants roots up out of the hard packed clay that is the norm in our region.  As we amended the garden beds with compost and peat moss to lighten and enrich the soil, we ended up with garden ‘mounds’ instead of garden ‘beds’.  These mounds were not particularly attractive and were irresistibly inviting to the nearby grasses and local invasive weeds.  We yearned for a cleaner, easier to maintain, attractive, durable, economical and space efficient solution.

Having drooled over many episodes of Jamie: At Home, Jamie Oliver’s beautiful brick raised beds at his home was what really inspired us to take action.  Unlike Jamie, we have a typical suburban back yard and limited funds with which to build raised beds, so we knew the beds would not be brick.  Sigh.

Considering the criteria for the raised beds I sited above and planning for a base raised bed size of 16 feet by 4 feet and ultimately 12 to 18 inches tall, here is what our research revealed:

  • Cinder Block: Cinder Blocks are readily available at just about any local home improvement store.  They are not particularly expensive and are certain to last a long time. For around $80 we could build a bed with a 16′ x 4′ internal dimension.  The rubs here are that we would need to provide a level base upon which to lay the blocks (lots of work in a sloping location) and we would be left with an unfinished top edge of block holes requiring another $70 or more to cap attractively.  Our final decision to look elsewhere for a solution was based on the fact that the external dimensions of the bed would be 17.5′ x 5.5′ due to the width of the blocks.  In our yard, the compounding width effect would diminish the number and spacing of beds we could create and still have enough yard for play.
  • Landscaping Blocks: Landscaping blocks come in a vast array of colors and sizes to choose from.  If your main concern is the appearance of your beds, these blocks would be good choices.  For our consideration, landscaping blocks have the same drawbacks as cinder blocks, and they cost 3 to 8 times as much.
  • Pressure Treated Lumber: Less expensive than blocks of any sort, pressure treated lumber is easy to build with and promised to last a good long while.  There are some scientific studies that have shown that the ‘leaching’ of the chemicals used in pressure treated lumber is very small, and little or no trace of it shows up in vegetables grown near it except in the case of root vegetables such as carrots are growing within inches.  I don’t really what to have to worry about where I grow my carrots, so no pressure treated lumber in my garden.
  • Builder Grade Lumber:  The inexpensive pine boards that are sold in every home improvement store were an attractive option.  For a total cost of $70 for lumber and stakes to build a 16′ x 4′ x 12″ raised bed that was less expensive than a cinder block bed and took up 1 1/2 feet less space!  The life span of the pine was questionable, though.  Would it last a year?  Two?  Five?  It would definitely rot rather quickly based on how long my tomato stakes lasted (two years).  Is there a better solution?
  • Engineered Lumber:  Sort of like ‘Engineered Hardwood Floors’, what I am talking about are decking products that are made out of plastics, resins and wood pulp.  These products will last indefinitely and have the same ‘low profile’ advantages as other lumber.  Sitting down to do the math, I found that our 16 foot raised bed would cost nearly $250 and would then only be 10 inches deep.

The answer came one day while our family was perusing one of our favorite stores:  Tractor Supply Company.   We were wandering around the outside portion of the store brainstorming creative uses for 1000 gallon galvanized water troughs (hot tub?), wire cattle fencing (Garden trellising?) and other such utilitarian treasures when we happened upon at huge stack of fencing boards.  Sixteen foot long, rough-hewn Oak boards.  Heavy, hard and beautiful, and at only $8.99 each!  I quickly calculated our raised bed cost to be $60 including the 2″ x 2″ x 18″ surveying stakes we would need to fix the beds in place.  The best deal yet!  The Oak will definitely outlast the pine lumber and is less expensive to boot.  We have a winner!

Two of our 16 x 4 foot raised beds constructed from rough-hewn oak fence boards.

Two of our 16 x 4 foot raised beds constructed from rough-hewn oak fence boards.

More details and pictures on how to assemble a raised bed from oak fence boards are on the way!

~The Suburban Hayseed.

Horse Poop Compost! Does a garden good.

We’re off to meet Bill, a gentleman farmer (farming Servers in the tech industry by day) who posted an ad on Craigslist offering up ‘Black Gold’ for free!
Bill’s composted horse manure will add the final touch to our soil amendments this year. A cubic yard of composted vegetation and a 3 cubic foot bale of sphagnum peat in each 16 foot raised beds has gone a long way toward making the native red clay more hospitable to plants.
Though it is common practice to fill raised beds with totally new soil, this somehow feels like it leads to a destruction of any sense of terroir.  We have carefully amended the existing clay which provides its own unique blend of minerals to flavor our produce.  Adding liberal amounts of sphagnum peat and both vegetable and manure composts have improved the fertility, drainage and water retentive qualities of our gardens.

~The Suburban Hayseed.

UPDATE:

The ‘Black Gold’ wasn’t quite as black as we needed to be.  It was a bit blonde with fresh sawdust not long from the barn.  Instead of forking it directly into the beds as planned, we piled it on top of our existing twig heap/compost pile so as to accelerate the action of both.  We wet it down well with the hose and covered it with a loosed bale of straw to keep in the heat.  A few weeks and a few turns of the pile and it will be rich and ready compost in perfect time to set our first outdoor seedlings in early April!