Nature's just too slow. I don't have centuries to wait and am fine with lasagna after a good hardy double dig.

There’s such a wide range of what people consider “clay soil”. My father’s large garden in an old established neighborhood has clay soil… but you can get a shovel through it without a ton of effort. It’s had life on it for a long time adding organic matter to it to a decent depth. It’s a brown color… but still considered “clay soil” My yard and many in my area with newer (less then 15 years) neighborhoods many times have the lovely basement excavation fill dirt yards. It has some portions that are solid gray clay. The bathtub effect can be an issue. So even when a plant says it’s fine in clay… you need to be careful of what type of clay you have.

"There’s such a wide range of what people consider “clay soil”. " That is only because many people really do not know what soil is. Soils are made up of 3 minerals, sand, very large and irregular particles, silt, smaller and of a regular shape since they are tumbled in rivers, and clay, small and very regular shaped particles that fit together quite tightly.

Sandy soils do not do a good job of holding either nutrients or moisture, because of the very large spaces between the particles which allows water to flow quite freely. Sandy soils, when rolled between the fingers will feel gritty.

Silty soils do a bit better but only because the spaces between the soil particles are smaller. Silt will fill in the larger spaces in sandy soils. Silty soils, rubbed between the fingers, will feel somewhat like rolling ball bearings there, smooth and regular.

Clay soil particles are flat and regular in shape and fit together quite tightly limiting the movement of both nutrients and moisture and plant roots, or much of anything else. Clay soil, rubbed between the fingers, will feel very smooth and slick, much like talcum powder will.

Sand and silt will, if enough is added, open up the clay soil so plant roots, nutrients, and moisture will flow easier. However, that takes a lot of sand and silt, about 50 percent plus. Clay, added to sandy and silty soils will fill in the spaces and slow down the movement of nutrients and moister, but again a lot of clay needs to be added, about 25 percent.

Organic matter, added to clay soils will also open up the spaces between the particles and allow plant roots, nutrients, and moisture to flow more freely and at lower levels, about 5 to 8 percent organic matter. However, correcting the problem will not happen immediately but may take a few years. Tilling organic matter in to clay soils only helps if a good depth is reached. An 8 inch depth is not enough and could produce that bathtub effect just as amending the planting hole would.

Organic matter, added to sandy soils, will close those spaces between the particles and help hold both nutrients and moisture in those soils longer allowing plants to utilize both.

Organic matter is the only soil component that is digested so it "disappears" over time as the Soil Food Web works on it converting that organic material into nutrients to feed the plants growing in that soil. Organic material needs to be replaced regularly to maintain the levels needed for optimal growth.

An optimal soil would be a mix of something like 45 percent sand, 25 percent silt, 25 percent clay and 5 percent organic matter, but few of us will find that mix naturally. Some few landscape supply houses may mix such a soil and if one is near you and you need a lot of soil (to fill a raised bed) that would be a good source to use.

It takes about 10 tons of organic material to raise the level of organic matter in soil 1 percent.

Yes, I tried to explain this to some a few months back. It takes a lot of work to keep a clay soil friable. It's not a losing proposition, but it requires on-going maintenance. Clay soils are often some of the most nutritious of soils. Keeping them amended and workable to good depths pays off in dividends, but one need be aware that methods like no-till, or lasagna, are severely limited in their effectiveness in many clays.

I have a bed that I stupidly let lay fallow this summer. I just got too busy with other things to put in a cover crop, or dig in leaves and mulch. I let some arugula self seed, but not enough to cover the bed. It was well amended down to almost 18 inches. I dug it recently to plant fall potatoes and I couldn't get the fork past 1 depth. Granted, part of the problem was the drought we've had this past month (just broke yesterday,) but not being able to dig it as well as in the past was a bit frustrating. The good thing is that it's potatoes, so when it comes time to harvest I'll get the potatoes out of the way (Lord willing and the creek don't rise too high,) dig out some soil, set it aside, and get the pick axe in there. I'll consider a deep root cover crop, but that's not as much as a cure as it is a benefit.

this is an object lesson to those who want to try these antiquated methods like lasagna. If you want black, softer earth at depth, you have to improve your bio-mimicry and plant deep rooted cover crops as often and as thickly as possible. You have plenty of choices and I recommend biennial crops, alfalfa and chicory, besides the annual but formidable tillage radish. The best time to plant chicory and radish is now in Zone 6. Other choices include the perennial red clover and sunflower. Amongst vegetables, beets are best, but turnip, chard, and types of chicory are good too. Once the channels are established other crops will be able to go deep, and the process will become more self-sustaining. Of course, any cover crop will be able to go below 5 inches, so anything is better than lasagna. Currently I am using oats, fenugreek, sunflower, tillage radish, buckwheat, alfalfa and hairy vetch.

That is what was the most interesting... after hearing how equivalently great lasagna method is vs double digging in amendments... I was expecting deeper progress then I have. Using leaf mulch leads to a lot more organic matter going into the soil vs wood mulch (from my experience)... and the worms are continually going to town underneath the leaves. So many years of adding OM on top no where meets to the quality of doing a single double dig.

Lasagna and similar methods do have some benefits. It's a great way to utilize the biologically active composting process if you have too much volume of compostables to fit into your bin. People who don't compost at all will sometimes be willing to do it, since it helps the poor soil in the process without a lot of work. Slowly, I admit.

I found the clay underneath my fallow-bed compost piles (whether they had soil layers or anything growing in them or not) stayed moist and didn't get compacted by successive rain and drought. It's also a low impact activity (on your back, that is) and many gardeners don't have the physical ability to do a lot of digging. Frankly in my case the clay was so full of clumps and clods, you could hardly amend it on a micro scale with one digging. I suppose it would have been beneficial to dig a foot down and try to amend all that in the first place, but it would have taken multiple diggings or at least a very powerful tiller to homogenize all that, and I had only so much compost available at once. It may have taken longer in the end to do it in stages, but at the time, improving even one shovel depth was a daunting task, let alone double depth. But if I have it to do over again I may try it. I'm not immune to good advice.

I did think we were doing a good thing getting people to use these methods instead of, for example, replacing soil with purchased topsoil stripped from somewhere else, or pricey bagged 'garden soil' from the store. Surprised to hear it's already 'antiquated'. I suspect many of the instant-gratification crowd will not be impressed when we tell them they have to dig and till their clay 16" down as a start, and any other approach is obsolete.

Definitely agree. Laying material on top is better then not.... and will keep your garden going fine. My beds that where not double dug have been performing well for years. It's just that double digging really ramps up the whole system. Once I started double digging new beds... I was able to compare identical plants in two planting situations. The less input of water... makes things a lot easier in high summer.

I think it's rare that a technique should be shelved - up and down hill plowing for example. However, what's known to most of us is that different soil types respond better to different methods of preparation and maintenance for different planting purposes. The lasagna method receives good reports from many gardeners. I use sheet composting in maintaining my veggie beds, but for my soil, it's not a feasible preparation method.

Although organic material will generally decompose over time, wood-type waste and anything with lignin in it will take much longer to break down - some humus aggregates will last for ages. In addition, humus can form humus-clay aggregates or clay-humus complexes - in part this is what gives the 'softer' clay organic soils its characteristics, including the brown colours, and it also helps to prevent compacting of the soil. It's probably not possible to say exactly how to apply this in amending clay soil of different types, but I'd be inclined to include some woody waste (particularly if already doing some digging), combined with other organics like compost, leaves, etc, to feed the other critters in there. Fungi also like wood waste and that has its own impact on soil.

I'm saying woody waste to avoid taking a position on what might work best - branches, logs, chips or chipped waste, sawdust, etc - as that will depend too and impact things like nutrient availability. I'm also not saying to do this in exclusion of other methods, like rooting crops or whatever.

I think lasangna style would be fine on a nice soil but when you are dealing with something very clay (like the muck we dug out from under the house) then I think it's best to grow something in it. Laying leaves and more leaves and more, more, more leaves (I was losing the plot a bit, one Autumn) I was disappointed to find after a year or two, that the clay underneath the squillions of leaves still looked the same. The worms hadn't been tossing and turning things up like I'd said they would be.

No argument there. With a very horrible pure clay it does take SOME tilling or digging in to get things started off. None at all would prolong the process for a loooong time.

And of course, cutting back on the tilling as the texture improves will help maintain the porosity that develops from worm burrows and all the microscopic spongification that goes on. :-]

"Spongification"............now that's a $100 word!! I like it :-))

Within extended family at country house we have very different views on how to approach the yard - particularly the sense of how it should 'look.' Note that the retired portion of the family has more time to spend in the yard, so by default some decisions are made by whoever is out there.

Anyway, just had a discussion with mother-in-law about how (despite lots of rain this summer) some parts of the yard just need lots of extra watering. And I went through the points I've made countless times that the mania for 'neatness' (meaning cleaning up and removing basic leaf litter, lawn clippings, etc) means that the soil ends up being naked and drying out and getting crusty. Our lot is largely treed and the soil tends to clay, so of course it dries out and gets harder. The small flower beds are nice 'spongy' soil but won't stay that way at this rate. The parts of the more heavily-treed bits where I've spread mulch and woodchips don't have this issue - they retain moisture and the soil is not crusty at all. (Forests don't usually have naked soil and they do okay)

I suppose this sounds like a bit of a rant about how people don't listen, which maybe it is in part; but I guess I mean mostly that ideas about 'neatness' and how stuff should look can just contradict basic soil health.

I've had the discussion about just leaving the lawn clippings where they are about twenty times - and every single time somebody else decides they need to be raked up. For mental health reasons (my own) there's only so much I'm going to resist. (The in-laws' old place had a beautiful lawn and they always raked up the clippings, but the soil base there is quite different - what works in one place doesn't in another...)

If you can just get people to mow right so the clippings are spread evenly over the lawn, they are nearly invisible anyway. I do that with 90% of my clippings and only bag a few times in spring when I need some garden mulch and greens for the compost.

It's hard to break old (centuries old) habits.

Yep, hard to change old habits. I think I'm slowly getting there with the lawn clippings and covering the soil. I've already had some success with the instinct to burn cardboard, paper and leaves; need to get a chipper or something to deal with the woody waste. Now if only more of the neighbours would stop burning everything.

Double digging or tilling are not the only options for manually decompacting soil or breaking up hardpan. You can use a broadfork or digging fork for a much less labor-intensive and less invasive decompaction that does not turn over or invert the soil layers and does not pulverize the soil. Both plant roots and worms will find it much easier to carry their work deeper down once the vertical channels are opened up in this way, and water will also infiltrate better.

It would be even more important to decompact without inverting or mixing if you're in a situation like the original poster described, which is well-improved soil to a certain depth with tough clay subsoil below. Five inches of good soil is nothing to sneeze at, and it would be counterproductive to then waste it by burying it down deep or diluting it by mixing it together with the clay. The vast majority of the plant root activity is happening at that top layer anyway - the incremental improvement to be gained by a deeper decompaction in this case would be better moisture management, not necessarily drastically better plant performance.

One good decompaction like this combined with the other important elements mentioned above - addition and replenishment of organic matter and mulch at the top, keeping plant roots in the ground (ideally with perennial cropping, or with "cover crops" or interplanting as a stopgap measure), minimizing disturbance to soil layers and soil fauna - should be all that's required.

Mostly agree with Parsley but the superficial root activity is OK only when there is enough precipitation. Superficial root activity also wastes nutrients. In my experience, nitrogen and water limit the performance of most gardens. In both cases going deeper helps substantially.

I am perplexed at the amount of thought given to this. I know that two daikon cover crops in a row will blacken the soil to 8 inches, no other work needed. If the OP plants one now and one next August he will be done doubling the black earth underneath (of course a mixed cover containing daikon will be better). But here it seems that every solution proposed involves work for very little results. Natural systems will do your work if you put them in a position to succeed. In particular they inject organic matter in well organized micro channels at depth, far better than any human can hope to imitate with his or her ridiculous mechanical implements. Other organisms follow the injected matter.

Great input all around. These lasagna only beds do just pretty much fine compared to my double dug beds.. Until summer hits and the differences become apparent. The double dug beds allow like plants to grow larger after a time since they aren't as stresses in summer.

For me... Just to get to the crud soil in these lasagna only beds.... I would be removing the top 5 or more inches of okay soil anyway... So putting in the extra work to complete remove a bunch of the worst stuff below that.... Breaking up the bottom.. . And the mixing back in a replacement bulk of compost.. is worth it at that point.

In regards to cover cropping... Since these are perennial flower beds... Leaving them cover cropped just isn't any option.... I'm too impatient for that. But I couldn't see a few years turning 8 inches of soil black from its original state if thirteen years of mulching heavily only gave me 5. Maybe I'll try some on a section outside my fence taht I might try making into an asparagus bed in the distant future.

What a great discussion. Many thanks to all.

I've been looking on and off for a good informational link on using a broadfork for deep aeration/decompaction, and I like this Youtube video which is fairly straightforward and shows the use of the broadfork quite clearly.

https://www.youtube.com/watch?v=22WjBjLiRoE


The model he uses in the video has 12 inch tines. Typically broadforks have 10 to 12 inch tines. See different models here:

http://www.johnnyseeds.com/tools-supplies/long-handled-tools/broadforks/

I would love my soil to be that loose!

But if I can jump on a sharpened shovel and only get the blade a few inches into my soil... one of these isn't going to go anywhere.

This would work on my raised veggie beds though.

>>>But if I can jump on a sharpened shovel and only get the blade a few inches into my soil... one of these isn't going to go anywhere.

But you just said you've been double digging it. How so, if you can't even get a shovel into it?

A broadfork is not the same as a shovel. It's designed to distribute your body weight into the tines when you stand on it and allow you to waggle the broadfork back and forth. The tines slice through the soil as you waggle, whereas the broad side of a shovel gets stuck against the hard soil.

This is how a broadfork gets into soil that a pickaxe has trouble with. It's visible effort, but your body weight is doing a lot of the work, plus the leverage of your weight against the tall handles. A better visual of very hard soil, but you can't really hear what this guy is saying until just after the 3:00 mark.

https://www.youtube.com/watch?v=_KBVJnKgsnw

See also this video:

https://www.youtube.com/watch?v=x_ymkVDTj0c

Reminds me of the days when I had to dig my clay with a potato fork. Nowadays the texture is so nice I can stick a shovel into it with one foot if I need to turn it over.

I'm the resident devil's advocate against clay. If you have even 1% clay I would be surprised. I say that after 15 years on this and other forums. Lots of people claim to have clay and few really have clay. What they end up having is a salt imbalance among sodium, potassium, magnesium, and calcium. When the salts are out of balance the soil becomes dense wet or dry and very sticky when wet. Even a sandy soil with a salt problem can have some of the clay characteristics.

The solution for clay has been well explained above. If that is your problem, then do all that stuff. But if your problem is a chemical imbalance, you can do that other stuff all year long and nothing will fix it. Rather than blaming it on clay, get a soil test that tests for cation exchange capacity as well as all the salts.

My soil is definitely clay, and it would laugh at a broadfork. Besides, they are way too expensive for me. I can't even get a digging fork in a few inches until after a season of maintenance and amending. And, while I can't speak for how anyone else double digs, I use a pick mattock and a fork to break it up and amend it deep. Once amended, mulched well, and maintained, it gets better. But, as soon as you stop amending and digging deep, it begins to revert to its original state.

Also, the Meadow Creature brand broadfork, in the video above, comes in 12", 14" and 16" tines - if you're manly enough for the 16" version.

https://meadowcreature.com/broadforks

Yup... definitely clay. Not only is it "clay soil”… Which I know is a subjective term on the internet… but there’s portions of solid gray clay too. When I was a kid, you could get this same clay from the creek banks…. Add a bit of water and make yourself some nice pottery during day camp or as I still have someone in the house… a nice turtle statue. I would say this is much more then 1%.

My double digging is done with a lot of pick mattock and spud bar work to break it into chucks… and then shoveling out the worst and breaking the rest up as I add better material.

The other videos do seem more plausible in clay with less teeth on them, but similar to rgreen… if I take my garden fork… and jump on it… rock around on it… it doesn’t go deep. And like a broad fork, all my 200+ lbs is being focused on 4 tines. Maybe the weight of a broad fork really does help though. But at the end of the day, if I am not getting some amendments down into the ground, it will lock back up on me like before. Since I am doing this in perennial beds too… this is a one and done type of thing. I won’t be going back in later to continually break up the soil.

I’ll see if I could rent on somewhere…. Would be worth a try. If it works, maybe Ill send you all a nice clay turtle!

Well, the official soil map shows silt loams in my area, but that's the surface, and when 8 ft of soil was removed for building houses and 4" of smashed clayey topsoil was added back on top of the limestone-based clay subsoil...well you come over here and I'll give you a baseball sized chunk of it to play with and you tell me. We got some stuff around here you can literally make a pot from. :-P

Some people may find this article an interesting read.

http://pnwsteep.wsu.edu/DirectSeed/conf2k2/dscclapperton.htm

>>Maybe the weight of a broad fork really does help though.

The difference (mechanical advantage) is created by leverage, not the weight of the tool. The broadfork tool creates a long lever, taking the force you are applying at the point where your hand grips the long handles and multiplying it in the slicing action of the tines through the soil. (I was going to say that the bar that you stand on is the fulcrum of the lever but in trying to dust off my ancient knowledge of mechanics with the help of Mr. Google I think that this must be a second-class lever, in which the fulcrum is actually at the point of the tine in the soil, the load - i.e. the soil - being positioned between the fulcrum and the effort.)

Standing on a digging fork in the soil and rocking it back and forth applies a similar leverage, but the force multiplication is not as great and the tool itself is less strong and stable. When you stand on a broadfork and grip the handles, you have two levers rather than one and they are both longer, so you are applying force at a greater distance from the fulcrum of the lever.

The force you can apply by pushing forward with your arms is also greater because your arms are in a position where you can apply more of the muscles in your back and where you can transfer more of your body weight into force against the lever. If you watch someone working a broadfork into very hard soil you can see that they are combining the force of their shifting body weight with the force of their arms pushing and pulling, repositioning constantly, stepping on and off the bar, etc. The stability created by standing on the bar and gripping the two handles enables you to pause, vary the movement, and also add a waggle from side to side when that's needed.

"The difference (mechanical advantage) is created by leverage..."

I got all the physics of the levering stage... these look much beefier then a shovel or fork. I've snapped an old good quality composite shovel handle...and cracked my current wooden by applying too much leverage while digging around over the years.

The problem I see is just "the getting one of these deep into the ground stage" with rocking or jumping etc. I'll still keep my eyes open for one in my area i could buy/borrow/rent and give it a try maybe.

Yep, I agree with Nevermore44... those broadforks look fantastic for turning what's already been broken up. They would save me a lot of effort and time working the beds. The problem is breaking new ground. It's just too tough to get anything at all down in there without a lot of work.

Who do know where to buy a shovel made of titanium? This tool is amazing! It is very light and cuts any hard ground like a knife cuts the bread. Loved it so much!

A growing root tip can have 20 atmospheres of pressure on it, while it keeps the coefficient of friction with the soil very low ( less than 0.1). A guy with a spade, no matter how sharp, can not, and the coefficient of friction is high (of order 1). But people do need the exercise, and so we keep on digging.

This may not be a practical solution for home gardeners and I wish they had presented some information about the soil, but still interesting. http://www.upworthy.com/a-juice-company-dumped-orange-peels-in-a-national-park-heres-what-it-looks-like-now

Me finding the closest orange peel resource

https://tenor.com/view/me-it-tech-technician-booty-gif-7476464

according to many members of this forum, if they had composted the peels first somewhere else, the results would have been better.