How to amend garden soil that's mostly clay?

[QChickieMama]

Sounds to me like you have a definite hard pan problem. Obviously, you are in a different climate than I am. I checked my favorite seed catalog and found the following 2 green manure crops that should be advantageous to you. Again, I recommend that you contact your county extension office for a list of green manure crops that would be helpful in dealing with hard pan in your climate and soil conditions. Bell bean is a nitrogen fixer which can be planted in early spring. Fixes up to 100#/acre in 6 weeks of growth, aggressive tap root breaks up hardpan and mines subsoil nutrients for secceeding crops. Forage radish (daikon): Fall and winter cover crop with a thick upper root 12-20" long and a thinner taproot up to 6' long. breaks up compacted soils and hard pan. Plant in stands of 5 - 8 plants/s.f. A good warm weather crop is buckwheat, though I don't know how well it would do breaking up your hard pan. I've never grown the first 2 crops mentioned, have grown buck wheat. If I were dealing with your problem, I'd take the whole garden out of production for a season of intensive cover cropping and mulching. I would start with Bell bean, work that into the soil (till minimally, don't try to get a smooth seed bed) follow it with repeated crops of buckwheat until onset of cold weather, then plant forage radish mixed with more bell bean, and field peas.

When you do till the garden, can you approach it from a different direction? Preferably tilling north to south if you have been tilling east to west. IMO, especially in clay soils, tilling does more harm than good to soil structure. clay soil is particularly vulnerable due to it's structure. Imagine a deck of cards: Those are clay soil particles. Imagine a bowl of marbles: Those are sandy soil particles. Imagine a bowl of little sponges: those are humus or compost particles. When you have clay, and work the soil, it lines those particles up so there is no space between them. That's what a potter does when he works a lump of clay to make a clay pot. The ideal soil structure is make up of the perfect blend of the 3 kinds of soil particles. I am a strong advocate of working the soil as little as possible, mulching heavily which will encourage build up of humus, and feeding the micro and macro soil life which will in turn nurture your plants and return the soil to good crumb structure. Now, will someone please loan my a ladder so I can climb down off my very high soap box???

It sounds like you have more land available to do a small garden adjacent to your current garden? If so, you could do a no till garden (research lasagna gardens), start gathering your material as soon as possible. When the frost is out of the ground, layer your materials, starting with newspaper or cardboard, aiming for a bed that is 2' high. I did a modified lasagna garden squash hill this last year, and raised 185# of squash in a hill that was about 3 x 4'.

I've found some daikon radish, and I'm waiting for the weather to warm up after this cold snap we've had. I'll sow some daikon in the garden and see what happens. Portions of our back yard are hard-packed orange clay. Could it be a good move to plant some daikon there as well? I don't much care what grows in the clay spots--I just want something to cover the clay and prevent erosion. Seems bits of the clay erode and expose just rock. Sigh. But once we warm up, I'm thinking 1. remove rocks, 2. put composted manure over the clay, 3. sow seed, 4. sprinkle peat moss over. Any thoughts about that?

I've also dug out the high part of the garden to encourage natural drainage. So I'll sow some daikon there. Only, now the clay/soil is in huge clumps. Would it be better to sow seeds in and around the clumps or work to level it somewhat?

I won't till this garden again. The tractor only fits in the plot one direction because of the deer fencing. I like the lasagna-gardening ideas, so I may incorporate some layers.

 

[1muttsfan]

The more tilling you do, the more your soil will compact. Also, before you add an acidic substrate (like peat) it would be best to do a soil test - ag departments at colleges and state ag departments will often do these quite reasonably. Acid, compact, cold, wet soil will grow very little of anything.

 

[sandspoultry]

We have the yellow eastern NC clay here in our garden, for the last 6 years I have been putting all the chicken manure in it every time we clean out the houses and in the fall all the leaves in the yard. They are mostly oak and maple leaves, they give us enough to put a layer down about a 1 foot deep in the garden. I run the tiller thru the garden a couple times in the winter when it's dry enough and the leaves are pretty much gone by spring. We do have 2 gardens a spring and summer and we rotate them every year, the spring garden gets cover cropped every summer. It's taken time but the soil is loose, drains well and warms up quick in the spring. I did notice over the years that the soil got "better" from the bottom up. If you dug down to the depth of the tiller tines there was a layer above the clay that that was nice dark rich soil and over time that layer got thicker and thicker. It just takes time.

 

[TXchickmum]

The more tilling you do, the more your soil will compact. Also, before you add an acidic substrate (like peat) it would be best to do a soil test - ag departments at colleges and state ag departments will often do these quite reasonably. Acid, compact, cold, wet soil will grow very little of anything.

I would definitely agree that adding peat to any garden beds would be detrimental. -cannot imagine doing that. (Per the advice of a professional, we opted to plant our blueberries in peat. They are contained in whiskey barrels with no other soil/compost/clay at all. -doubled in one season!) -agree with the tilling, in general, as well. Our clay was like brick due to drought conditions in areas, that it had to be broken up/tilled before any compost and soil were brought in to raise the beds. (-would have been like dumping "good" dirt onto concrete.) -had to consider our climate, which is very different from other parts of the country with clay soil. Tilling would be counterproductive to areas with lots of precipitation. -would make for poor conditions.

 

[lazy gardener]

I've found some daikon radish, and I'm waiting for the weather to warm up after this cold snap we've had. I'll sow some daikon in the garden and see what happens. Portions of our back yard are hard-packed orange clay. Could it be a good move to plant some daikon there as well? I don't much care what grows in the clay spots--I just want something to cover the clay and prevent erosion. Seems bits of the clay erode and expose just rock. Sigh. But once we warm up, I'm thinking 1. remove rocks, 2. put composted manure over the clay, 3. sow seed, 4. sprinkle peat moss over. Any thoughts about that?

I've also dug out the high part of the garden to encourage natural drainage. So I'll sow some daikon there. Only, now the clay/soil is in huge clumps. Would it be better to sow seeds in and around the clumps or work to level it somewhat?

I won't till this garden again. The tractor only fits in the plot one direction because of the deer fencing. I like the lasagna-gardening ideas, so I may incorporate some layers.

Without seeing the lay of your land, I don't understand why you dug out the high part of the garden. IMO, again, this is without seeing what you're dealing with, it would be preferable to keep the garden as high as possible. Did you perhaps mean that you dug out the high soil adjacent to the garden? The rock exposed after clay erosion: what's under that? is it packed sub soil or is it ledge? Sounds like your best bet would be a combination of lasagna gardening and green manure crops with alternating beds: Work on soil improvement in one area, while you grow crops in an other area. I forget if you've said whether you have a chicken tractor. That would be a great help to you. You could park it over one bed to be worked on, throw as much deep mulch as you can get your hands on into the tractor, (ideally, a layer at least 4 - 6" deep would be fantastic. Let the chickens work it for a couple of weeks, then move it on to the next spot and plant a green manure crop there. You could do a deep litter/mulch/chicken manure followed by green manure progression several times in each spot over the course of the summer.

 

[QChickieMama]

Without seeing the lay of your land, I don't understand why you dug out the high part of the garden. IMO, again, this is without seeing what you're dealing with, it would be preferable to keep the garden as high as possible. Did you perhaps mean that you dug out the high soil adjacent to the garden? The rock exposed after clay erosion: what's under that? is it packed sub soil or is it ledge? Sounds like your best bet would be a combination of lasagna gardening and green manure crops with alternating beds: Work on soil improvement in one area, while you grow crops in an other area. I forget if you've said whether you have a chicken tractor. That would be a great help to you. You could park it over one bed to be worked on, throw as much deep mulch as you can get your hands on into the tractor, (ideally, a layer at least 4 - 6" deep would be fantastic. Let the chickens work it for a couple of weeks, then move it on to the next spot and plant a green manure crop there. You could do a deep litter/mulch/chicken manure followed by green manure progression several times in each spot over the course of the summer.

I should try to attach a photo of this silly garden! I'll explain here. The tilling in the garden caused the naturally low-lying edge of the garden when all the extra water would seep to be built up by 8" or so, so that all rainwater is pooling inside the garden area. I think I understand making the garden high is a good thing, but that would be after establishing proper drainage.

In our yard--under the clay? I'm not quite sure. All our acreage is quite rocky. Anytime we want to plant a tree, we have to choose a few spots before finding an area where we can actually dig down enough. Otherwise we find 12" rocks, so of which we can lift and some not. So, in the grassy part of the yard, where we've been TRYING to grow grass, there are maybe 10 3' areas that are red clay with 1" small rocks. I joked once that if I worked hard to remove all those small rocks, we might no longer have a back yard. Once we tried to aerate our lawn with the tractor, but the tines seemed to bounce off much of the soil, barely penetrating in some areas.

The chicken tractor idea is a great one! Give those cute birds something to do all day! I do imagine moving the tractors would get tricky. Perhaps my guys could lift them to new areas now and then.

Thanks for your help.

 

[lazy gardener]

Some folks mount their tractors permanently on wheels, others have wheels that drop down. Some are dragged on skids. When we moved our hoop coop (which was supposed to be a tractor, but it ended up being too heavy) my husband and I moved it about 100' using 10' long lengths of 2" PVC for rollers.

Is all of the soil in your area like what you're dealing with? I'm wondering if the soil was scalped off your lot, and you're left with nothing but bony sub-soil.

 

[nocalroo]

dig trenches 2'-3' wide and 12''-20'' deep remove the clay ad a layer of 2"-3" layer of large gravel for excess water to drain then add 4 parts soil conditioner, 1 part chicken manure, 1 part organic compost (leaf pile, kitchen scraps, coffee grounds), 1 part horse manure 1 part drainage (perlite, volcanic stone, crushed brick all #1 size). once you have layered these components in the trenches mix them I have done this by hand but have also used a rototiller, go for a good even color. This is a decent first crop soil mixture you should also mulch your garden with old leaves or even a bail of alfalfa will do wonders for next years garden just add a little more #1 sized drainage each year to keep it from getting compacted, you need water to drain in clay soil.

 

[Euarto Gullible]

I used to have hard pan clay soil in my backyard that I had to work with a pick axe. I had an area that I had piled a foot high with grass clippings for mulch, and they had been sitting there for about a year. I was astonished to find that once I stripped those grass clippings away and began to turn over that soil, my shovel slid right in like butter...and the color was brown instead of white clay. If I ever have hardpan again, I would just spread a foot thick layer of leaves or grass clippings and just leave it for a year. Obviously not a short term fix, but if you're looking to expand your gardening area, it's worth a try.

 

[lazy gardener]

Case in point about the value of mulch!