Question
My soil has a high clay content, it's red, gets very hard when dry, retains water, becomes very slippery when wet,  and when it dries it holds any form or imprint that was made on it when it was wet. How can i improve the qualit of the soil? I have about 1/2 acre to treat.
I look forward to your response.
Thanks


Answer
High clay soil?  Welcome to the club, Samuel.  

The Old School would prescribe Pelletized Gypsum to break down the clay.  But clay is high in Calcium; Gypsum is high in Calcium; adding one to the other does not really improve soil quality and Gypsum does not really change the texture of clay.  So ignore that advice, even if someone at Home Depot recommends it.  

It sounds like you have some really intense clay.  As if your house was built on a clay slab.  Which we have lots of on Long Island.  

You will have to add a LOT of organic amendments to your clay.  

Peatmoss.  Compost.  Aged Manure.  Humus.  Dead Leaves and cut Grass.   

Coarse Builder's Sand should be added, but not by itself.  A large percentage of your amendments has to be the organics listed above.  If not, you will end up with something very similar to cement.  Hard as a rock.  Worse than before.  

Earthworms will take a full season to condition your soil.  But they will do an incredible job.  If you have been using Insecticides (such as "grub control") or anything hostile to insects, you probably have a minimal Earthworm population.  If any.

You're going to think I am crazy, but Starbucks is giving away bags of used coffee grounds.  Although coffee is highly acidic, the grounds are a little more neutral.  And this stuff attracts Earthworms for miles.  So if you are short on Earthworms, you can invite them over with some tasty bags of coffee grounds sprinkled all over your clay.  

These also repel slugs.  But that's the least of your problems right now.

Organics separate the minute clay particles, allowing air to get in.  All plant roots need air to grow.

NEVER work your clay while it is wet -- after a deluge or a simple storm, or you will find yourself creating some impossible hardpan that will be a REAL problem.  Work with dry soil.

Since you are working with a respectable piece of properpty, you will have to get these things by the cubic yard.  Get 4 cubic yards for every 1,000 sq ft of soil you want to fix.  Mix amendments all together into the top 4 to 6 inches.  

Let it sit a few days.  Then have the soil tested.  

This is a common problem, Samuel.  You can't take any shortcuts unfortunately.  If you have the best topsoil in the world delivered -- and it will never be as good as the stuff you can make yourself -- the topsoil will be sitting on top of an impenetrable layer of clay.  Which will flood every time there's a thunderstorm.

Any questions?

I'm here.  Thanks for writing.