Breaking down clay soil

This is my second year with a garden. It’s a large garden but the 2^nd nonetheless. I read, read and read some more on this site and a few other green thumb sites to gain as much info as I can to convert my red Georgia clay into anything but pottery.

   



I have read that calcium/gypsum helps break down the clay and offers plants much need nutrients - especially tomatoes and peppers. Question: Is a bag of 90 minute drywall mud okay to use? Basically it is the same stuff as “garden grade gypsum” but may have bonding agents in it.  I can’t find any listed on the bag. It is considerably cheaper.

Scruffy, why do you want to do that instead of building boxes and throwing in some Mel's mix right over the top of the clay? Are you using the SFG method for gardening?

CC

Scruffy, you should next read "All New Square Foot Gardening 2nd Edition" before you do or read anything else. It will change your life. Really. Get your garden above that clay, and you will never ever look back.

I haven't any experience with gypsum on clay.  I added large amounts of grass clippings and other compostibles dug into the clay and let it do its thing for a bit before planting and then mulched heavily with more grass clippings.

[url=/u12849]CapeCoddess[/url] and [url=/u28069]Scorpio Rising[/url]: To respond to your questions first: If you remember me from last season, my garden is 125’ x 100‘ just slightly more than ¼ acre. Establishing a raised garden above grade is cost prohibitive. Adding topsoil and amendments last year above the compacted clay proved to be costly as it all but washed away. Huge drainage problem.
This year I have dug almost 2’ deep with a sub-soiler and mixed in about 80 cu. yrds. of aged wood chips approximately 12 inches deep. This has effectively solved my drainage problem but set the acidic level to 5.3 so I added 1,400# of granular lime to raise the PH.
My concern is compaction as clay has a tendency to do just that. My understanding is that gypsum breaks up the molecular structure of clay while adding calcium and other beneficial trace elements.
I am a general contractor by trade and know that calcium is added to gypsum to reduce setting time i.e. from 90 minutes to 45 min to 30 min depending upon how much calcium is added. That’s a good thing as plants do need calcium. However, I do not know and have yet to find out if there are any detrimental bonding agents added to the gypsum that may have an adverse effect on plants.

Turan wrote:I haven't any experience with gypsum on clay.  I added large amounts of grass clippings and other compostibles dug into the clay and let it do its thing for a bit before planting and then mulched heavily with more grass clippings.

Thanks Turan.  I have worked wood chips into the soil but the county agent said I needed to break up the clay.  I asked about adding sand and he just laughed.  From what I have read gypsum does something to the clay to make it loose (for lack of a better term) and the county agent confirmed this.  However, I don't want to do to  much at one time if there are bonding agents that may have an adverse effect.

I don't expect to accomplish this in just one season so I am looking for a means to break down the clay and add beneficial minerals at the same time during the next few seasons.  I have a great compost pile but not large enough to service 1/4 acre of space.

Scorpio Rising wrote: Scruffy, you should next read "All New Square Foot Gardening 2nd Edition" before you do or read anything else.  It will change your life.  Really.  Get your garden above that clay, and you will never ever look back.  

I am a compulsive reader so I will follow your suggestion.  I do want to raise the grade a little but at present I am attempting to do that with wood chips and compost so that is why I need to get the clay to perk.

Yes, that jogged my memory. I think if I were you, I would break your large area up into priority levels; then work on optimizing one zone at a time, much like phasing a project. That way, you can get the most out of the improved plots and move on to the next.

Compost your tush off! I know zero about gypsum...but if the extension guy says it works, ask him who you could talk to that it worked for.

OK, this does sound promising, Scruffy!

https://www.humeseeds.com/gypsum.htm

Try it on a section or two...can't hurt too much, right?

I seem to recall that you added huge amounts of forest duff last year.  Can you plant in that and then do a heavy mulch?  I am thinking a round bale of alfalfa hay (make sure it was not sprayed with a persistent herbicide).  The deep mulch will both help solve the clays texture problems, stop weeds, and keep the clay from compacting.

A note on sand.  I add sand to my beds now and it is recommended here along with large amounts of organic matter.  The caveat is that the sand needs to be coarse, not the nice soft stuff used in sand boxes.  The fine sand and fine textured stuff like peat apparently mixing into clay can become like cement (adobe I guess). 
This link says a good bit about that and some about the nuances of using gypsum.  It does not answer your basic question about builder grade vs gardeners grade gypsum.
http://www.bachmans.com/Garden-Care/divHomePage.html?cnb=GardenCare&categoryCode=02&pageIndex=_pageIndexToken_workingWithClaySoil

Best of growing this season!

I am reading that builders grade gypsum is pure except there may be a trace amount of boron that helps in the slurry somehow.  So, for me that would be ok, my soil is boron deficient.  But for you?

Turan wrote:I am reading that builders grade gypsum is pure except there may be a trace amount of boron that helps in the slurry somehow.  So, for me that would be ok, my soil is boron deficient.  But for you?

  Actually, you are right about the boron.  When the soil samples came back that is one of the things that was suggested as an additive.  I am thinking of adding one cup of borax to each bag of gypsum but now, I may not need too if it is already in the mix.

What I am still looking for are any bonding agents in the powdered gypsum that may be detrimental.  There are none listed on the bag.  I will call the manufacturers lab to get that info. 

Thanks for the info.  I am going to read the site you sent now.  Maybe I can learn something.

Turan wrote:I seem to recall that you added huge amounts of forest duff last year.  Can you plant in that and then do a heavy mulch?  I am thinking a round bale of alfalfa hay (make sure it was not sprayed with a persistent herbicide).  The deep mulch will both help solve the clays texture problems, stop weeds, and keep the clay from compacting.

A note on sand.  I add sand to my beds now and it is recommended here along with large amounts of organic matter.  The caveat is that the sand needs to be coarse, not the nice soft stuff used in sand boxes.  The fine sand and fine textured stuff like peat apparently mixing into clay can become like cement (adobe I guess). 
This link says a good bit about that and some about the nuances of using gypsum.  It does not answer your basic question about builder grade vs gardeners grade gypsum.
http://www.bachmans.com/Garden-Care/divHomePage.html?cnb=GardenCare&categoryCode=02&pageIndex=_pageIndexToken_workingWithClaySoil

Best of growing this season!

Wow! lots of great information on that site.  Here is what I learned in the past 20 minutes on a few other sites: "ORGANIC TRADITIONS" GARDEN GYPSUM is 10.32 for a five pound bag. As a general contractor I can get regular gypsum in 45 pound bags for only six dollars. Obviously we have a no brainer here IF there are no bonding agents in the construction grade gypsum that would prove to be detrimental to the soil. As I said in the other post - I will check with the manufacturer’s lab. Thanks for the help.  I will keep you all posted on anything that I learn.

Turan,



when I asked the county agent about adding sand he did say I could make matters worse even by adding mason's grade (very course) sand. He cited the same reason you mentioned regarding turning the soil into concrete. That having been said, I do have several hundred cubic yards of wood chips on hand. The problem here is I have to keep a close eye on the PH level and the nitrogen deficiency caused by the decaying matter.



As I mentioned, I don’t expect to do all this in just one year. Last years amendments have helped some areas of the garden so I am having good luck with the corn, beans and peas I have already planted. I will be planting peppers and tomatoes next month so I am trying to tweak the soil the best I can before I plant but I am still not expecting miracles to happen this year.

Scruffy, If you like reading, then definitely read All New Square Foot Gardening. As second read is Teaming with Microbes.

Since you don't use SFG beds, there is a video on building up instead of amending the existing soil. It's a long one, and there are shorter versions and other folks' testimonies. Back to Eden. https://vimeo.com/28055108

At this point, I would only apply material to the actual plant "beds": manure, cheap bulk compost, chips, leaves in the fall. Just pretend you have wood sides on the rows and build up. Don't forget to have breaks or isles in the rows to cross over to the other side for planting and tending.

Just my take on your huge acreage.

sanderson wrote:Scruffy,  If you like reading, then definitely read All New Square Foot Gardening.  As second read is Teaming with Microbes.

Since you don't use SFG beds, there is a video on building up instead of amending the existing soil.  It's a long one, and there are shorter versions and other folks' testimonies.  Back to Eden.  https://vimeo.com/28055108

At this point, I would only apply material to the actual plant "beds":  manure, cheap bulk compost, chips, leaves in the fall.  Just pretend you have wood sides on the rows and build up.  Don't forget to have breaks or isles in the rows to cross over to the other side for planting and tending.

Just my take on your huge acreage.

Nice pre-emptive strike Sanderson, as I was bound to launch an onslaught of questions regarding “building up“. If you remember last year I had an bunch of mounds all over my garden. The mounds did fairly well so I have been thinking of raising rows and am working in that direction. I will watch the video you suggested and search for more. Thanks. I really am a compulsive reader but that is not necessarily a good thing as I can fill my cranial caverns with so many conflicting suggestions that I find my mind spinning as a child’s dradle. I often find myself coming back to this site for clarity.

I did forget to put in crossovers. It is a long walk up and down these rows J . The entire garden isn’t planted so I will correct that short sight as I continue. As of last night I have been on several BTE videos regarding all these wood chips and the best way to make use of them.

The reason I gravitate toward SFG is because most responses are from people that have actually experienced the same problems or are going through the same problems I am experiencing. Lots of positive feedback regardless of the size of the garden.

I am using the wood chips primarily in the walkways. I sprinkle 30 -0-0 over the walkways to help breakdown the chips but not burn up the crops in the rows. I have 18 acres of pine so I gather the needles for mulch over the rows. I am just experimenting right now - kind of like stumbling around in a drunken stupor. My goal is to get this down to a science in about three years so we can generate some much needed revenue off our little ½ acre garden. Right now it is only ¼ acre bur as I learn to manage the land I will expand to the full ½ acre.

I do realize SFG is for much smaller gardens, but the help I have gotten here has proven to be very beneficial.

scruffyfeathers wrote:Turan,

when I asked the county agent about adding sand he did say I could make matters worse even by adding mason's grade (very course) sand. He cited the same reason you mentioned regarding turning the soil into concrete. That having been said, I do have several hundred cubic yards of wood chips on hand. The problem here is I have to keep a close eye on the PH level and the nitrogen deficiency caused by the decaying matter.

As I mentioned, I don’t expect to do all this in just one year. Last years amendments have helped some areas of the garden so I am having good luck with the corn, beans and peas I have already planted. I will be planting peppers and tomatoes next month so I am trying to tweak the soil the best I can before I plant but I am still not expecting miracles to happen this year.

I think what your will find that as time goes on with wood chips, compost and mulch, it improves each year. Your attitude is good, in that you will not expect miracles in a short time.  As you are doing, concentrate your resources on what you want for this year, the rest can wait its turn. 

What I am enjoying myself  is the improvement in my garden over the last three years after the years I spent in the beginning with only moderate returns. Even in my smallish area, there are places that I have not touched but I look forward to consolidating what I have done and there is always something new to do when I have the time and inclination.