Advice for Clay Soils

[OaklandCityFarmer]

We have very clay soils here, I mean, you could mold with this stuff and it retains it's shape with no problem. Dries out and it's hard as a rock.

We've been able to do some great stuff by adding TONS of compost to our soil and having it get much better.

Are there any tricks or tips anyone else can provide me with?

 

[ams3651]

I think compost is great but what you need is soil. Maybe raised beds would better. If you are trying to use the clay you should get topsoil.

 

[patandchickens]

I have to respectfully differ with ams3651. Don't avoid the clay. Clay is not a bad thing at all -- it has some very GOOD points, such as good water-holding qualities (i.e needs less frequent watering) and generally excellent fertility.

You just have to (as OaklandCityFarmer is already doing) work with it to prevent its bad points from surfacing. Those being, that it typically has dreadful drainage, is very cold and late to become workable in the spring, and can dry like bricks - cracked bricks! - in the summer. The solution to almost all of those problems is just what OaklandCityFarmer is doing, dig in lots and lotsa compost.

Do not be seduced by those who say add sand. Unless you add an unrealistically enormous amount of sand, what you will create is concrete that's even worse than the original clay. (If you're going to add an unrealistically enormous amount of sand, which is not really the best solution, make it very coarse sand, not the find builders' or play sand).

It is sometimes suggested that you add gypsum to help flocculate the clay into bigger less homogeneous particles. I have read, however, and am willing to believe, that this DOES NOT APPLY TO EASTERN OR MIDWESTERN clays... only *certain* Western clays. Due to soil chemistry stuff. Definitely anyone contemplating gypsum should research the subject in some depth first.

You do need to be attentive to site drainage on clay soils. There may be some parts of your property where you can't plant (well, can't plant whatever you want -- there is *something* that will grow *anywhere*) unless you can divert surface water and/or drain subsurface water. French drains, soakaways and tiling are sometimes suggested. However my observation is that they are only suitable for *some* sites, and some clays can be so clay-ey that subsurface drainage is not highly pointful.

If you cannot improve drainage enough for what you wanna plant, your only alternatives are a) raised bed or b) don't plant it there. With a raised bed on clay, I would advocate coarsely, but deeply, breaking up the native clay soil underneath the raised bed (like, turn it up in big clods with a shovel) before putting your fill soil on top.

The only other things I know of are the relatively-obvious... don't work nor even walk on the soil when it is at all wet (can be formed into interesting play-doh style shapes with your hands), and never let it completely dry out hard in the summer. The more organic material you have in it, the less likely hard drying is.

But don't knock clay. Many excellent gardens are built on clay, not despite it but *because* of it. Much as many of us like to whine about it (and believe me, on a property that floods like this one, I can whine about clay like nobody's business if you get me started ), clay is actually a fairly good substrate for a garden as long as you WORK WITH IT and also RESPECT ITs peculiarities

Good luck,

Pat

 

[OaklandCityFarmer]

Thankfully I don't have extremely clay soils or too many low spots on the property. I guess for the most part we'll continue to just do what we've been doing.

Thanks for the great insight, as usual.

 

[countryatheart]

During the dry summertime, I am thankful to have my clay soil. My Dad lives about 10 miles north of me and has sandy soil. He has to start watering far sooner than I! However, during a rainy spell, I often lose plants because they are too wet! I constantly add compost, lawn clippings etc. to my garden and beds.

 

[aquarose]

Wow. I would have suggested adding sand. Thanks Patandchickens for that illuminative info.

 

[Auntie Ron]

Hi,

I also have clay. I have been amending now for nearly five years and I can honestly say that every additional year of compost amendments have created some lovely plant growing mediums.

I just wanted to chime in because I got some advice long ago about clay which I have followed. I was told not to ever add ashes to clay, that it binds the clay and prevents oxygen from entering the soil. It was explained to me that the lack of oxygen will suffocate a plant.

So I have been very careful not to add the ash from a burn or from a fireplace. Maybe someone could clarify this or discredit this; I just have not wanted to do any trials.

Ron

 

[Backyard Buddies]

We also have clay soil here as well as at the church garden plot. The "double digging" method is what will work. Dig down as far as you can go and drop the soil into a wheelbarrow. Take a garden fork and poke it in the hole and work it around to loosen the soil some more. Dig again and remove the soil. Mix all the soil you removed with compost, then deposit it back into the hole. Your soil will now be a higher bed than you started with, which gives your plants some room for the roots to go down, and might actually allow you to grow long carrots instead of little orange stumps!

It's a lot of work to double-dig, but your plants will thank you!

A product that was recommended to me by multiple sources (landscaper, county extension, and multiple growing groups on the Net) is Gro-Power Plus, that has a soil penetrant in it.
http://www.gropower.com/product_pages/gp_plus_product.htm

The master gardener at the county extension said Gro-Power Plus is the only fertilizer she uses in her garden.

 

[Southern Gardener]

I too have clay soil and I put my garden right on top of where my burn pile used to be, but I did add lots of compost. So far everything is growing beautifully - I already have tomatoes.

 

[Farmer Kitty]

I have heavy clay soil here. Compost works great! I'm adding a new section this year and the difference between it and the old section is huge!