I don't know what your idea of "quite a bit of compost" is, but you'll probably need way more then you think. Other then that, mix it in.

I have the same type of clay soil as you, except I had tons of rocks in mine. I removed the stone in one section then added compost in it's place, last year. I'm talking 8 yards of compost and it made my clay great to plant in.

With this new year, I've found that my compost is slowly turning to humus and making my red clay brown. With this change, I've lost mass, so I'm in the process of adding more compost. So far, I've added 4 yards this year, but it looks like I'll need more.

Good Luck!!

You can never have too much organic material (compost).

Clay, itself, is great stuff as far as a good soil profile. It's very good at holding onto and exchanging nutrients. Having nearly all clay, however, isn't fun.

Depending on how much you plan on to amend your soil you probably should get a pH test done to see just how acidic of a clay soil you're working with. They tend to accumulate acidity.

I've seen suggestions online and heard from others about adding sand to improve drainage. Don't...especially with the amount of clay it sounds like you're working with...it'll become bricks.

You may have to add enough compost/topsoil or other soil conditioner to the point where you have to remove some of your clay soil and relocate it, though. You could make something cob-construction style (clay, sand, straw) with it if you're really bored...heh. Built a cob doghouse just this past summer with a "green" roof. Messy stuff, but cheap and its something to do.

With a clay soil the biggest problem for plants is how brick like it gets when dry. Using a mulch helps prevent it from turning into a brick and if the mulch is a woody product (like leaves or wood chips) it actually changes the clay to a clay/loam soil over the years (think a decade or more, it isn't an overnight process, but each year helps).

Adding compost or other organic matter can't hurt and only help, but you really need an organic mulch over the top of the clay to keep it moist and prevent it from becoming a plant killing brick.

I have clay, also. Don't know if its clayey enough for the cob construction, tho. May have to give that a try for fun.

Anyway, the clay with added organic material works well for me....EXCEPT for root crops, ie beets, carrots, radishes, potatoes. They grow but not very well. I have done some simple raised bed areas with the edges bordered with logs and have not mixed the compost in very deeply. This gives 6-8 inches of not so clayey soil to use for the root crops. Seems to work here.

Have those of you with clay walked around turned up ground after rains and ended up with ten pounds of clay stuck on each foot? How about getting stuck in a very wet spot and wondering if you would be able to get out without someone hooking you up to a wench? We built our home mostly ourselves and had some slippy, sloppy times. I will never forget the challenging days after big rainstorms!

I make sure to stay out of the garden when it get really wet. Don't need it to lose all it's structure.

I have the same clay, maybe worse. I've tried everything when I was a newbie, including tilling in various amendments and it did nothing but make my problem worse. My development lost all it's topsoil when they built houses and graded the land. The result from tilling made a hard pan 6-8" down and made the soil turn into concrete. I couldn't work it with a shovel.

I then learned about lasagna gardening, and no-til methods. I've only done it for a year but I can tell you it made a dramatic change. I even fall planted cover crops this year and can't wait to see the results.

So to conclude the best thing you could do is get a hold of organic matter and pile it up. Cardboard, paper, grass clippings, used coffee grounds (start collecting them from Starbucks), straw, leaves, manures (check horse stables, most people are happy to get rid of it, just make sure it's not fresh), fish scraps, kitchen scraps, wood shavings and feed store grains are viable choices. Most of them are free as well.

You can directly plant into a fresh lasagna garden too, as long as you don't have any fresh manure in there you shouldn't have any problems. I had raised lasagna mounds that I planted in and they were about 2 1/2-3ft high. By the end of last summer the mounds have become flush with the ground. Which is the only thing you need to watch with lasagna'ing, you must continuously add matter because it will decompose.

I've got serious clay out here in the plains. I've tried numerous things, but raised beds turned out to be the salvation. I start a bed by double digging - not as much labor as you'd think - and then mixing in 2 inches of compost each spring. when i can, i grow a crop of green manure and turn that in. Mulching is absolutely required as the others have indicated. This year i'm trying a soil less mix of peat, vermiculite, and compost that the book by Bartholomew recommends. It's to early to tell how thats going to work but i only did one bed like that. Anyway, if you use raised beds and keep after it, the clay turns out to be pretty rich and will eventually make a good garden.

Thanks for all the tips guys. Strange naturegirl, last summer I planted beets and potatoes and they did fairly well, I had added SOME compost but it wasn't very good. Then I did do alot of hand loosening the soil (something I would like to avoid) it was murder in the hot sun! Crabjoe, "I don't know what your idea if quite a bit of compost is" hmmm, never been very good with measurements, lol, but I would say 3 or 4 wheel barrows full, if that helps at all = ) nc-crn, yeah I've heard about adding sand too, they say only add sand with large grains, but I have been wary of it (b/c like you said it can make your soil worse) and decided to go with organic material instead.

Thanks again for the help! Any more advice would be welcome

This anti-sand bias makes no sense at all, and I don't mind if I am the only one that will say it. Google "soil triangle". Loam soil is made up of clay, silt, and sand. Is compost mentioned? No. I have been adding sand to clay loam soils for 40 years, and it has never failed to immediately and permanently improve the soil. I also use compost, but it cannot take the place of sand as a soil conditioner. It has lots of other great attributes, and does help improve clay soil, but not like sand.

There may be clays that do not respond well to sand, so I suggest that you buy a bag of sand for a couple of bucks, apply it 2" deep to a small area, till it in, and see if you like the result. Obviously, if you have dense, pure subsoil clay, nothing is going to work, and you may as well pile good soil on top of it.

If you live in the Portland, Oregon area, come on over and I'll show you what can be grown in a clay soil improved with sand. I'll demonstrate that I can dig a 10" deep hole with my bare hands in soil that hasn't been tilled in 20 years. Sandy loam is the most perfect garden soil you can have. You just need to be open-minded enough to try it.

The sand amendment doesn't work for red clay at all, unless you are planning to make bricks.

My garden spot was so hard that the first year here when the farmer came with his tractor to disc it up he POPPED A WHEELIE.

Here are my suggestions for clay: avoid "working" the soil if it is completely dry (you'll break your back or your heart) or if its too wet. When wet, you're just destroying the structure and making concrete; when dry its just impossible to break the soil and if you do jackhammer it open it becomes rubble and dust...still unusable. When the moisture levels are correct, the soil works like a dream and QUICK QUICK QUICK work in bark fines (finely ground bark), compost, etc., plant your seeds and COVER THE SEEDS WITH GOOD SOIL, NOT THE CLAY. Mulch your walkways, mulch around the plants. Add more mulch every year. Plant cover crops for the winter OR layer the beds with hay, straw, pine straw, grass clippings, or ground leaves.

This anti-sand bias makes no sense at all, and I don't mind if I am the only one that will say it. Google "soil triangle". Loam soil is made up of clay, silt, and sand.

This is true, but be careful because cement is (can be) made from clay and sand. The practical problem facing the gardener with sandy soil or clay soil is what type and how much to add. Get this wrong and cement is the end result.

Get it right and loam is built in a day (there is a sort of pun in there). Is compost mentioned? No.

No, it isn't mentioned because it isn't a type of soil ;-) Compost can improve most soils, but isn't a soil type, it is an additive. An additive that will decompose to next to nothing in a year or three. There may be clays that do not respond well to sand, so I suggest that you buy a bag of sand for a couple of bucks, apply it 2" deep to a small area, till it in, and see if you like the result.

Very good advice.

Back to the OP, just cover the soil with 3-4 inches of an organic mulch. Leaves (chopped with the lawn mower), small wood chips etc. Something wood based. It will immediately improve things by keeping the clay soil moist and soft and over many years will improve the soil by adding humus to the clay. No, the clay soil won't improve quickly, it will take a decade or more and that is why the organic mulch is used. It keeps the soil moderately moist and soft while the tilth is being improved.

Clay soil is awesome (I have pure clay in my yard. Well, not really, it's pure clay plus rocks).

You can grow more in clay than you can sand and with much less effort. Clay is superior in water and nutrient retention. It lacks only in aeration/drainage.

Anything needing superior drainage can be grown in clay by elevating the growing area above grade (raised beds).

I don't know how large an area you plan to soften with those few barrows of compost, but when I amended my clay, it was aprox a 50:50 mix of compost/clay. With that said, you'd be amazed at how much different the soil is. When I dig below the amended depth, the clay below is as hard as bricks. The amended stuff is soft enough I could probably stick a plastic knife into it.

Thanks again. My only aversion to the sand was because being inexperienced there is that chance I would make a mistake, where as with compost/organic matter you can't go wrong.

So really just adding a top layer of mulch would do? I understand it would improve the soil over time but would I be able to plant this year?

True, not all clays are created equal.

A clay in the northwest US mountain/volcanic country isn't the same as a southeast US aged/weathered clay even if they share the same important water/nutrient attributes.

That said, a little sand isn't going to hurt a clay soil, but you're in for a fine line between safe and brick with most clays. The reason its blasted so much is most people can't do it right and there's a better option for most in using organic matter if they're digging up a fresh bed to begin with.

Not only does the organic matter build aggregates better, but it also works very well with the clay to exchange charges/nutrients. they're a great match.

There's lots of ways to go about tackling the problem, really. Heck, if you don't mind burning the clay to death with fertilizers and a tiller you can grow in soil forever without adding anything to the soil profile, but you'll be dependent on your fertilizers. Personally, I'd use a topsoil/compost mix with my clay in a hybrid "raised bed/dug bed" setup, but there's so many "right" ways to do it.

I was at the garden mart today and asked what to do about clay soil. The girl there recommend something called Clay Buster. I plan on doing a google search to see what others think about it.

Many folks think they have clay and don't. It's best to find out how much clay is in the soil before selecting an amendment strategy. If it turns out you really do have a high percentage clay soil, then sand is the solution.

Once the sand has been added, if a sample is divided into its components it might look like this ...
{{gwi:33779}}

Gone will be your dependence on compost, nor will you need mulch either. Slugs won't come to your garden, you won't need fungicides, and if you manage it right your weed problems will go away too. No more round-up!

Mostly I grow flowers, but because this is the vegie forum, my sweet potatoes grown in a sand/clay mix ...

{{gwi:33780}}

Wow, some nice potatoes there pls8xx! I know for sure that I have clay soil. It is possible to make bricks out of it, in fact we have. My clay isn't red though like the stuff in the pic, it's more of pale beige when dry, and a dark brown when wet.

I have another question though!
Since we also have pretty high winds out here, I was wondering if I could fill my cold frame with some good soil and have it double as a sort of raised bed? Maybe dig down a few inches so that the roots can go deeper, and of coarse don't plant anything too tall. Would that work? Out here you really need protection from the elements. My cold frame isn't very big, 4' by 6' wood frame, slanted sides and a plastic top. I know cold frames are generally used to harden off plants, but I'm wondering if I could use mine for the whole growing season. Has anyone here every tried that?

Clay is a lot like that soda pictured above. There's a lot of colas and they all "do" the same thing and taste similar, but the things that make up the cola tend to be different.

A lot of the volcanic clays of the northwest and some of the south/south-west mountain clays are a lot more prone to heaving/cracking/negatively-aggregating and tend to be of smaller grain size than the 'hard pan' clay common in my area of the south-east. Both are extremely small particles, but what makes up these particles are generally different sources and differing levels of weathering/aging through the soil profile.

They may both turn to sticky mud on the surface when wet, but when they dry they show some interesting differences in how they reform soil aggregates (not counting soil baking which can crack/crust even on soils with a low-ish clay content).

The reason people see much about organic material over sand is 1- its just a generally safe guideline not taking in account the personal knowledge of the person working the land and knows what he/she can put in it and 2- organic material works in tandem with clay to very efficiently move nutrient exchange more so than other soil amendments.

My garden is clay. I get mini grand canyons in August. Over the past 35 years I've added at least 10 truck loads of mushroom 'manure' (the mushroom houses were accross the road where the brick works used to be) and one truck load of sand, also several truck loads of aged horse/cow manure and a few bushel baskets of chicken manure (note, keep the windows open when you transport the stuff in the back seat of the old Dodge Dart) My garden is pretty small, 7 4'x20'
raised beds. I think the answer is to add whatever you can get your hands on in the way of organic matter and keep doing it every year. (oh, right, I forgot the composted vegetable matter every year, too, and now I take the grass clippings from two neighbors who do nothing but mow their lawns)

sand IS the way to amend certain clays. in my area we have buckshot/gumbo clay with a topsoil layer of good sandy loam from the MS river silt. if you dig down to the clay, it is a hard layer. if the topsoil is thin or nonexistant at your location, you bring in sand and till it in. after a couple years or so of doing this, many people have great luck at changing their clay over to sandy loam. some people won't do it right andf the result is that the clay actually sucks all teh sand DOWN over the summer. they spread it or sany loam on top and when the clay cracks during summer the topsoil sucks down and you actually get a topsoil layer 3-4 feet underground! the key is to mix it up good so that the clay won't crack apart.

you can then add compost as necessary, but the sand must be done first.

as to red clay, the kind close to here is already very sandy. and it does make nice bricks.

Great posts.

My best success was 4-5 years worth of tilling seasonal leaves into (small) garden plot. Garden was maybe 20fx20f, leaves piled thigh-high. By the time we sold the house, it was dang nice soil to work with. New owners put sod over it all.

Starting over at a new larger location, have been adding stuff for years but nothing has beat building compost rows over my raised beds. They start out approx. 2-3.5 feet tall and by the end of the season are practically level with the garden. But you can actually work that soil with your hand - elsewhere you'd need a pick and sledge. Stepping into the garden now is asking for trouble, it will eat footwear that's not securely attached. Not even a wench can get you out of it..

Got a truckload of leaves from a freind last fall, just waiting for the mud to dry out so I can get started on tilling the leaves in again. Too impatient for leaf mold, and I know what vast amounts of leaves can do to the clay!

Bottom line: with clay as a starting point, it'll take more than you think, and as much effort as you want to spend on it, to get it "improved"!

Thanks again to everyone who has posted, really appreciate it : ) sfallen2002, can't believe they put grass down instead of a nice garden! I know what you mean, leaves can work wonders, there's a spot at the side of my property where they all collect at the gate, over the years thereÂs inches of beautiful soil back there, to bad there are too many trees to plant a garden!

Sfallen,
How big a wench did you try? Maybe if she was larger she could get you out of it...

:)