Clay into: more clay

Was just perusing Lenjo's new thread on verbascums and noticed that Terry posted a comment about heavy clay soil remaining heavy despite all the organic matter put into it.

I thought this was interesting enough as a thread on its own. We have heavy adobe clay and in phases over the last 18 months, had dug 6-8" of it out, put in top-quality compost and mulched with cocoa hull.

I've noticed that the clay seems to 'travelled' up a bit. The soil is definitely a bit harder than during the first 6-8 months, although still nowhere near as bad as it was.

This was one of my objections to the oft-used 'the worms will turn it (clay) into good healthy loam.' We definitely had worms, but in 12 years past they never turned that clay into anything else. Clay soil is common in many parts of CA, and if worms turned it into good soil over time, given a few thousand years there shouldn't be any clay soil left in CA by now--but there is!

It seems to me that clay remains clay, unless you put in so much organic matter that the clay becomes a very small percentage of the soil. And that worms are merely the sign of a healthy soil, not necessarily the makers of it.

What's been your experience?

Loam is a mixture of soils, no amount of organic matter or soil life will create loam.

We have heavy clay soil here too(with lots of rocks in it). When I started working on the gardens about 10 years ago, one couldn't drive a stake in the ground in the middle of July. There were some earthworms in the soil. Over the years I've added tons of organic matter to the gardens, lots of manure and lots of peat and more worms. Now I can dig in most of the gardens quite easily and the soil is nice and loose but there are still stubborn patches(on slopes where the good soil keeps washing away).
I think worms can only do so much and they need organic matter to mix in with the clay or it won't get better.

The clay soil where I live is literally like potter's clay -when it is wet you can take a piece and wring it between your hands and it will just twist like rope. Centuries ago a number of potteries were created in this area because of the available clay. My parents moved into this place in 1965 and have been gardening ever since, most of those years using compost and mulch. And I swear the clay eats it all up and spits out clay! I gather huge amounts of leaves from my yard and the neighbors and shred them each fall to use for mulch and mix into the compost. I also use straw mulches and add composted manure, mushroom compost, and I can't even remember how many other types of soil amendments. My soil is much better than the native clay as I discover each time I dig a new bed but it is still heavy clay. I find that adding very coarse sand (not fine sand, that just creates cement) and compost to the clay is the best solution for me. The problem is I don't have enough of either. I agree with you, Jkom51 - in my experience the percentage of clay needs to be really small for amendments to be effective. My neighbors and I are discovering that since we are using shredded leaves for winter mulches we are getting a lot more worm activity in the beds and it really is helping to loosen the clay at the surface anyway!

Clay is clay, and I don't think you can turn it into anything else. However, I have noticed the opposite effect, as you suggest. The good stuff you put in and on top gets swallowed by the clay.

My soil is hard, heavy clay ... with lots of fat happy earthworms and lots of naturally occurring organic matter for them to feed on. I've added compost, leaf mold, gypsum, peat moss, sand, I can't think what all else. It's a temporary fix at best. I really think I do more harm than good because so many earthworms get killed in the process. I give up. Life is too short.

I'm building raised beds where I can. Where I can't (under the oaks) I'm using containers up on bricks until I can brainstorm a solution.

Cheri'

My solution to my very heavy clay in my veggie garden was to add so much organic matter (compost and shredded leaves) for such a long period of time that I created raised beds. The soil level is about 6" higher than originally, and I now have very enriched clay soil ;D But at least I can dig in it all year.

I would love to be able to add equal amounts of gypsum, sand and organic matter to make a loam of about 18" deep all over my property, but my back and leg say no way!

Clay is just rock particles that are very tiny. Sand is rock particles that are big. Silt is about half the size of sand. The smaller the particles, the less room between them for other things, like air, water, organic matter, etc.

Lupinelover, I am curious about your raised beds. If they are not framed how do you keep the heavy rains from washing them away? I think your very enriched clay is a good thing - clay is actually very fertile because nutrients don't flush out of it as easily as sandy soils, the problem is there isn't enough oxygen and it is so difficult to dig in, as you say. And then there are the delightful cracks that develop when it dries up - in a dry summer I can get cracks 8" deep and 1" wide. I have not used gypsum and had to stop using mushroom compost because my soil is alkaline and both of those increase the alkalinity.

One of the things a garden center here advises is adding some small crushed rock (about 1/4") to the clay. I add everything I can (mulch, compost, composted manure, Nature's Helper, etc.), and the top 2-4" seems to be getting better after 5 years, but it is a constant battle.

Darius, I add crushed rock or grit when I am planting individual plants that need excellent drainage, I can't afford nor do I have a strong enough back to redo all my beds with crushed rock!! What is Nature's Helper? I have never heard of that. I recently created a bed around a large maple tree. I turned the sod over and put a thick layer of newspaper on it and covered it all with several inches of compost and mulched it with shredded leaves. It will be interesting to see over time if the clay 'rises' to the surface or if the top 6" or so will remain friable.

NoWater, Nature's Helper is an amendment sold at Lowe's & HD. Looks like quite small pine chips, peat, etc. and costs about $3-4 a bag. I quit using it after I discovered I could buy what they call 'leavings' from the bulk organic materials place by the pick-up load for $10. It's what's left when they double-grind mulch.... not too fine like dirt, but smaller than pine bark mini-chips.

I, too, can only afford to add crushed rock to individual plants. However, I am thinking that when this house sells and I start another garden elsewhere, it might be worth the effort and cost to have someone bring in a truckload of small crushed rock and till it in before I start a new garden.

When I start new beds, I don't bother to turn the sod, just newspaper and mulch/compost, and keep it moist for several weeks until it starts to break down. In 5-6 months, I have a good planting area.

I took out my maples as they grow so fast and need constant top pruning, and nothing will grow under them, unlike my magnificent 100+ year old oaks which do need pruning but I cannot get anyone to climb and they cannot reach it from a bucket without destroying my yard.

Darius, I think you would be wise to amend the soil first. On another thread I mentioned the old gardening axiom of spending 95 cents of your gardening dollar on the soil. I ignored that when I was a young gardener but now I know how true it is!!

I live with my mother now so these beds already existed. If I were starting over I definitely would put my money in creating wonderful soil first even if it meant just having a few pots of annuals the first year!

When you layer newspapers and compost on sod to create new beds, do you find the clay eventually taking over or does the top part stay friable?

The maple tree is about 40 years old and quite beautiful. It shades the south facing part of the house from the summer sun and has beautiful foliage in the fall. However the roots are a problem; we have to put stuff in the pipes to keep them out. I created the new bed there just so I wouldn't have to mow so close to the tree trunk and roots. I have had hostas in there and they have done okay, now I have put in impatiens and hellebores. Hopefully they will all coexist comfortably.

The hellebores will love the dry shade under the maple; the hostas will tolerate it, and the impatiens will need a lot of supplemental water.

Have you tried hardy cyclamen or epimedium? Both love dry shade. The cyclamen are absent during the spring and summer, but the impatiens will hold their space while they rest. I am doing a similar thing under one of my haw trees -- shallow rooted too.

I have brick barriers by one of my raised veggie gardens; another has a clay hill ridge, and the third nothing. The third (actually, the original veggie garden) has things growing in it year-round, so that holds the soil in place. I have winter cover-crops as well as hardy onions, that is where I over-winter my lettuce, beets, carrots, etc.

I add about 4" of compost and about 8" of ground leaves to my veggie gardens yearly. Plus most of my green manure crops that are used as a straw mulch during growing season gets turned in, too. Very fertile soil :)

LL, I have hardy cyclamen and epimedium in a nearby bed which is under a roof. Those plants do really well there; so do the hellebores, arum italicum, moss phlox and various spring ephemerals. I would love to hear about how you do your winter cover crops. I have been wanting to do that in my veggie patch too (now it is mostly tomatoes and dahlias and glads). The problem is that it is at the bottom of my sloping yard and in spring is basically underwater - especially these last few sopping springs we have had. I have never tried to cover crop because the soil would be too wet to turn the cover crop under in the spring. If I created raised beds here I might be able to do that.

One of the strange things about that bed is that is where I planted glads years ago, thinking that I would dig them up in the fall and store them since they aren't hardy here. For some reason I didn't get around to digging them up and the next year they came back despite the winter cold and spending weeks in waterlogged soil in the spring! Each year I add more glads and they all keep multiplying. I have had no sign of disease or thrips - they seem as healthy as can be. Why they don't just rot is beyond me, but hey, I'm not complaining. I think it is wonderful. I just can't understand it!

About clay - I dug a rose out for a friend the other day and what I had to blast off the roots before I could take it to her would have made a lovely pot, had I the time. I've found here that leaving the clay where it is and building on top of it is the only way to get good garden soil. We have 3 large beds with rock walls around them. the soil that was there sloped off into the yard so we filled in the "pit" formed by the walls with barnyard dirt, saw dust, composted manure and some field dirt from the couple of areas on the farm that are of a finer tilth. The new veggie garden is built over an old building spot where the rubble was left. Stan hauled out the lovely crud that forms under the wood piles in the basement and I put that down over newspaper to hold down the weeds, then Stan hauled in 2 large bucket loads of dirt from the meadow he was putting oats on. It was a millet pasture last year so there are year old stalks and manure incorporated into it already, along with some really interesting weed seed, of course, but new weeds are easier to get rid of than well rooted weeds.

I realize that most people can't just go out and get themselves some good dirt, so I heartily recommend "Weedless Gardening" by Lee Reich. He advocates building good soil from the top down, as nature does. It is a wonderfully readable book and full of a lot of good stuff.

It has been my experience with newspapers that NOT turning the sod over is actually the better way. I think the rotting plant material under the newspaper helps it to break down faster and you don't have to dig through layers of tough paper the next year to plant.

I have tried several methods with newspaper, and I agree that it does seem to work better if just left on top after it is dead. But sometimes I am too greedy for that half-dead sod as a boost of humus for a different bed, so I have used it as a mulch, too. Either way, it is superb!

NoH2O, I will try to start a thread on winter cover-cropping in the Veggie forum in a few weeks, when it gets closer to the time for doing it. I grow hairy vetch and alfalfa in the winter, buckwheat and dill (dill!) in the spring and summer.

Thanks, LL. I'll look forward to reading that.

NOH20- I have had the same experience with the Glads. Mine are under a Crimson Maple and for the last three years they keep coming up- except for this year. I only had one. It must have been the really cold winter.

Davena

Davena, how sad! I cursed the snow cover that persisted all winter, but it sure kept all my marginal bulbs alive.

Ok, as a potter of 34 years, I will tell you that it is true, clay begats clay. It grows. Sorry to tell you this, but unless you remove all of it, and I don't think you can, unfortunately you are stuck dealing with it.

Everyones advice is great and you can only keep amending and keeping the soil loose.

Is anyone here familiar with a product called "Liquid Gypsum" put out by Soil Logic Pro and EZ-Flo? EZ-Flo sells a liquid fertilizing system that is injected into the irrigation system.

They claim that it has the "ability to displace sodium cations and replace them with calcium cations, and then create a positionally stable aggregate structure all in one operation."

http://www.ezfloinjection.com/pdfs/LGspec.pdf is the web site that describes this product in detail.

I've been using this product for the past two months and I believe I can see an improvement. One example are my Vinca minors. Up until now they looked like squashed cabbage leaves. Now they are look like they have come alive. Our soil here in Lincoln, CA is really bad. Heavy clay with rocks and has very poor drainage. It's been hard to find anything that would grow in our hot sun, poor drainage and survive frosts in the winter. Even Oleanders have a rough time here.

My, that's a very intriguing product, greatswede! I can think of a couple of areas we didn't improve that could really use this EZ-Flo stuff. And it might help to further amend the soil as much as possible, afterwards. Although I really hear everyone about how exhausting it is!

I remember reading one gardening article where the expert recommended amending soil as deep as possible - he said he liked to go down 18"! He must have had muscles like a lumberjack and a back made out of titanium, LOL.