Thanks for your gardening question, Adam!  You have quite a challenge here!  So, the two initial challenges you have are (1) removing weeds with taproots and (2) making certain there are as few weed seeds lying dormant as possible.  I urge you to absorb the concepts shared in this Extension article, since weed control in an organic garden is an ongoing challenge.

Although you're not removing sod, here is an excellent article about removing unwanted plants from a space, whether you're replacing it with a vegetable garden or a new lawn.  This resource, too, on pages 3 and 4, has some excellent (and cheap!) suggestions about how to cover the soil over the winter, suppress weeds, and add organic nutrients in advance of spring planting.

So, remove sod/weeds; cover with an organic mulch and/or an organic weed suppression agent; and remove any remaining weeds in the spring by hand pulling, tilling under and/or light/water control.

Hope these are helpful.  Good luck!

Thank you very much for all this very useful advice and info. Much appreciated!
Can I ask if dandelions and docks have taproots?
And also, will horse manure be OK to use as an organic mulch? We would be adding it now and leaving until next spring. Will that be enough time to allow it to decompose? Or do we need to only add fully decomposed manure?
Finally, would you recommend adding the layer of organic mulch under a layer of cardboard or above? Or both, like a lasagna? 
Thanks again, Adam

Dandelions have taproots; ‘dock’ is a general name foe about 200 species of annual, biennial and perennial plants, most of which have taproots (I’m not sure which you have.) Horse manure is better than chicken manure (animal anatomy) and can be used any time, as this article explains: http://articles.extension.org/pages/42319/how-long-should-horse-manure-age-before-applying-it-to-my-flower-and-vegetable-gardens-how-much-shou Lasagna mulching has proven very effective in supressing weeds, and helping soil micribes. Just don’t use cardboard that has reinforcing plastic filaments! They’ll make a mess of your garden! BTW, which town is your garden in? MYbe we’ll come visit someday!

Hi again Kristena, hope you are well, we have been busy in the group these last few days and have got it good and tidy. We have been concentrating on the weeds with taproots and digging deep to get them out. It's not easy is it. Some of them go down and down and I have snapped off lots unfortunately. Is there any way to treat the roots with some kind of organic substance that will help kill them? That was my first question. The second is, is it totally necessary to cover the area with horse manure prior to covering with cardboard? We have amassed lots of cardboard and are set with that + lots of pallets to weigh it all down. We have also found a source of manure. But it is proving tricky to pick it up as we needs loads of it, the lady is not always around, and the access to the garden is limited when we would have to get it from the trailer to the garden. I appreciate the benefits of laying manure and would still like to. But do you think it would be ok to leave it until laying after we remove the cardboard in the spring as a mulch? The ground we have is actually pretty good. And it would be so much easier if we had the flexibility of adding it later. BTW our community garden is in Peebles just south of Edinburgh, Scotland. If you were ever over this way it would be my absolute pleasure to show you around. It's a lovely place! Thanks again, Adam

Hello, Adam! (1) I know of no organic herbicide that will kill the taproot. It will, however, die without nutrition from the leaves, so keeping them cut off or smothered (by the cardboard, which you can keep down between the rows even in the growing season) are really the only solutions. If you can acquire any, the discarded burlap coffee bean bags also make good soil covers. (I know your country prefers tea, but I can't find any comparable shipping container for it.)

(2) Horse manure ages more quickly than, for example, poultry manure, so worrying about whether its nitrogen content will be too 'hot' for your garden is less of an issue. Here's one one source says:

"Fresh manure is high in soluble forms of N, which can lead to salt build-up and leaching losses if over applied. Fresh manure may contain high amounts of viable weed seeds, which can lead to weed problems. In addition, various pathogens such as E. coli may be present in fresh manure and can cause illness to individuals eating fresh produce unless proper precautions are taken. Apply and incorporate raw manure in fields where crops are intended for human consumption at least three months before the crop will be harvested. Allow four months between application and harvest of root and leaf crops that come in contact with the soil. Do not surface apply raw manure under orchard trees where fallen fruit will be harvested."

And, over time, "The residual effects of the manure and compost are important. Some benefit will be obtained in the second and third years following application. When manure and compost are used to fertilize crops, soil organic matter will increase over time and subsequent rates of application can generally be reduced because of increased nutrient cycling. Continuous use of manure or compost can lead to high levels of residual N, P, and other nutrients, which can potentially be transported to lakes and streams in runoff or leach and pollute the groundwater."

So, this year will be the last you'll need to scour for manure for a while.  But, keep putting it down over the cardboard, which won't prevent microbes from reaching it to help in the composting process, as you can obtain it through the winter, and, with the caution noted 2 paragraphs ago, your soil should be ready for plantings.

Thank you for the invite!  I may take you up on it someday!

Adam: You can put manure on top of cardboard, rather than under. Exposure to the air will result in a different decomposition process, but it will all end up the same. Put it on in any layering method you can. Just be cognizant of the cautions I noted in the prior article about unaged manure around root veggies. Plan your garden so as to avoid fresh manure on or around those plants mentioned. Putting it earlier on already-laid cardboard (over the winter as it becomes available) is better than waiting to spring. (Or have the horse owner compost it on her property as the mare makes it available, and bring it in semi- or fully composted.) You need not stress about the taproots. Just look for any new leaves, and either cut them off religiously or try again with the root digging. One group of scientists says vinegar can be as effective as Roundup but (1) it’s only effective on the new seed leaves and (2) it is an acid, which can negatively impact the soil and other plants it hits. Finally—and this may seem crazy—some gardeners actually keep dandelions because they attract pollinators AND you can eat their leaves if you haven’t applied and herbicides! As they say: pick your poison! Best!

Great stuff Kristena! You have helped us out a lot and it is very much appreciated. We want to keep thing as simple, natural, and wild as possible and are willing to welcome the odd weed or two into the mix. We will eat them too! We have lots of cardboard now and will start stripping off all the tape, staples and metal bits tomorrow ready for laying on Friday. Please come and see us if ever you make it to Scotland. Many thanks again, Adam

Happy 2018, Adam!  How is your (now fallow) garden plot doing?  I recently came upon an article that I thought might interest you, and decided to take a chance you're still reading your mail!  It's on composting, manure and food safety, and I figured you weren't yet out planting so you might have time and interest in reading it.  Hope you find it helpful!

Hi Kristena, many thanks for your message, kind wishes and very useful article! Happy New Year!! All is going great with the garden. We now have four more (even bigger) plots that we are preparing in a similar fashion for use as community gardens. Funny, I was planning to get in touch with you again this week to ask you a question about one of the new plots. We followed your advice with the first plot and it is all looking good. It is completely covered with cardboard and waiting an imminent covering of lots of well-decomposed horse manure. We have finished preparing another plot that is almost twice the size of the first one and have already had a nice big free delivery of manure from a local farmer (see pic 4). I have a regular source of big sheets of cardboard from a furniture store and they are even good enough to drop loads out at the gardens for me (they are happy as they used to have to pay the council to take away their cardboard "rubbish"). One of the newer plots we have is very clayey and stoney (see pics B5 & B10) and I would like your opinion on the best course of action with it. I have already floated it by the group and some people have said not to bother with it at all as clayey soil like this is "impossible" to grow in or at least takes too much work to whip into shape. I like a challenge and am inclined to think there must be some great food growing use for the land. What would you suggest? The three options I have thought of are incorporating lots and lots of organic matter (would this alone change its structure eventually and enough?), growing fruit and nut trees only (we can get lots of fruit and but trees free), or building raised beds on top of the land. I would be very interested to hear your thoughts and thank you in advance for any input. All my best, Adam

Hello, Adam! We live in the World Capital of clay soil (thanks to the Missoula Floods several centuries ago), so we know something of the problem! But, instead of your glass being half empty, it is 3/4 full! Did you know that all of the 'breadbaskets of the world' are located in clay soils? (You'll note they're not hauling a lot of veggies out of the deserts!)

So, since I live in 'Primo Clay Territory,' I've become fascinated with soils, microbes, nutrients and composting, and I recommend you read this Atlantic article that explains how the chemicals in and that make up soil interact with equally valuable microbes. You might look around to see if you can find some sources of microbes which will speed up the decomposition of organic material so texture and nutritive values are improved faster than you can imagine!

Here is a link to an excellent article out of our University that explains why adding organic material can improve any soil--and especially make clay soil even more productive. You can impress your fellow gardeners by mastering the subject of soil in this article. It's all chemistry, you know! BTW, you might want to test your soil texture by following the instructions in this easy guide.

You will want to get rid of as many stones as possible, but building stone walls goes back a long way in your country! (And you thought they just wanted to keep out the English!) The second article, above, lists the plants that do well in clay soil before the organic matter has improved the texture.

As to planting fruit and nut trees in clay soil, there are few that do productively, but I found one (New Zealand) source that says: "Peaches and citris.  Free draining spots needed. When planting on clay it’s best to plant on a slope and take care to improve the soil when planting. Grafted Citrus trees do better on clay soils than cutting grown trees, and those on a full-size rootstock tend to do better than those on dwarf. "   Since I don't know whether you can grow these typically warmer-climate trees in Scotland, your choices may be limited.  I would check with your local garden store to see which trees in your growing zone might thrive.  Just know that their shade will, eventually, limit the herbaceous plants you can grow beneath them.

If you really get into this whole soil and soil science area, I highly recommend you read "The Hidden Half of Nature; The Microbial Roots of Life and Health."

Please keep me informed of your progress.  Love the photos!

Warmly, Kris

YESSSS!!! Thanks Kris. Love your positivity! Such a nice change on this topic to hear a can-do response. I would very much like to stick it to the doubters and get something growing on that plot. Those articles you linked to are awesome. I am also totally fascinated by soil and will read them tomorrow. Were over in Spain at Christmas (my wife is from Bilbao) and one of my friends was telling me about a few cool techniques related to what that article from The Atlantic was discussing. Completely makes sense and we will be trying a few things out soon once the manure is spread on all the plots. I am pretty certain we wouldn't be able to grow citrus or peaches where we are, unfortunately. The trees that I was hoping to grow (I can get these free and they are native to Scotland) would be hazel, hawthorn, blackthorn, wild cherry, elder, crab apple. Do you think these would grow in clayey soil? I really hope so. This particular plot is right next to an endless source of horse manure so we could add loads of it constantly. Would you recommend adding lots of this over a period of time prior to doing anything (trees or veg)? To be honest with this plot I think I would rather grow the trees, but if fruit and nut trees really aren't suited to clayey soils I will rethink. Thanks again Kris. And here are a few more pics so you can see what we've been up to...

You're doing a great job!  And involving kids!  And having fun! And clearing brambles!

So, as the UConn article I sent you says, be careful about putting uncomposted manure on your edibles.  It takes about 6 months before the pathogens are broken down by heat and sunlight.  Putting them in the soil very quickly involves non-pathogenic soil microbes, too (it's a dog-eat-dog world down there!  One gram of soil has over 1 Billion bacteria!)  If you can adequately supplement the clayey soil on the hill you pictured in the first response, there will be adequate drainage for shrubs and trees.  Just don't expect much flowering/fruiting for a while.

Here is a link to an Extension article I just happened across out of U of Minnesota (whose latitude isn't much different from yours.)  Obviously some are not native in the States, and won't be in Scotland (think "Japanese," "Norway" and "Korean") but some of the species you noted are here.  (N.B.: some varieties are hardier than others.)

So, I can't be there to help shovel ****, but I'd like to contribute the book I mentioned to you.  Send me your (full) name and your address, and I'll order it forthwith.  Happy gardening!

Thanks again Kris! I remember you said before about leaving the manure for about 6 months at least and getting the well decomposed stuff. We will be doing both. All the gardens will be left for at least a year. Apart from the first really weedy one that we are planning to build the raised beds on. We will have to source some compost to fill those with. I have checked that link and it looks like crab apple trees are OK in clayey soil. Hawthorn requires well draining soil. Doesn't say anything about hazel, cherry, elder, blackthorn. Do you know if they would grow? We could just grow lots of crab apple trees there. Going back to incorporating the organic matter... do you think if we kept adding lots of manure over the course of this year that by November (when we would receive the free trees from The Woodland Trust) it would be sufficiently improved in terms of drainage? Should we incorporate anything else besides manure? I really would appreciate your opinion on this as we should crack on with a plan for this plot and it is the only one I am not clear about. Finally, about the book, it looks amazing! But I can't ask you to get it for me. That is really really nice of you though. Thanks Kris!

Adam: first, tree clay/compacted soil tolerance:
Hazel(nut):  The American hazelnut grows in acidic, alkaline, loamy, moist, rich, sandy, well-drained and clay soils. It is drought-tolerant.  (!)
Cherry: The American Arbor Day Foundation website lists 10 varieties and subspecies. Of these, the Autumn Flowering Higan, Japanese Flowering, Kazan, Nanking, Purpleleaf sand, and Sargent varieties can all tolerate clay soil. But some yield few if any fruits, and may not be tolerant in your climate.
Elder: (American)  The American elder grows in acidic, loamy, moist, rich, sandy, silty loam, well-drained, wet and clay soils. It can tolerate some drought conditions.
Blackthorn (Prunus spinosa):  Tolerates clay soil if well drained, per RHS.

Now, as to compost(ing):  Creating compost, whether atop the soil, in a compost pile or bin, or in a container, really is just trying to emulate Mother Nature's magnificent work in the soil.  (I'm going to synthesize the information you can find at this website and its related links.)
 
The common "recipe" is 1 part 'green' to 2 parts 'brown.'  This is really describing the ratio of carbon (C) to nitrogen (N), (C:N) which you want to be 25-30:1.   "Green" organic material is that high in nitrogen (but relying on the color can be deceptive: coffee grounds are 'green!')  Green matter can be broken down by bacteria, which have no mouths and depend on acids to 'deconstruct' cell walls they encounter.  And, because they live only 15 minutes or so (before they divide or die or are consumed), they must act quickly.  So they 'burn hot.'  It is through aerobic (must have air) bacteria that the heat of the compost pile/bin/container is created.  And heat kills pathogens (biotic structures that harm other biotic structures.)  So, to heat up a compost pile, you add green material.  But you don't want it to get so hot that it kills the 'good' microbes--bacteria and about 5 other microscopic entities (microbes) necessary for health--soil and animal.  Manure is high in nitrogen, so it is classified  "green," but nitrogen content changes over time as this article explains (although I haven't yet mastered it.)

"Brown" organic material is that with fiber, among other structures.  So, if you think of a tree, the bark, wood, branches and stems are 'brown.'  Brown matter can't be broken down by bacteria.  The cell structures are too dense, and bacterial acid isn't strong enough to break them down.  However, the soil (and the air, for that matter) have rather magical other microbes, including fungi, which have the ability to penetrate cell walls.  (Fungi are not plants.  They cannot photosynthesize, and must rely on plants for nourishment--just like animals.  In fact, we have more DNA in common with fungi--which have their own Kingdom--than plants.)  You've seen the white/gray 'tendrils' on the undersides of logs and fallen branches.  Those are hyphae, which grow out from the center mass of a fungus (the mycellium) looking for food.  The hyphae can penetrate 'tough' cell structures, and, in the process, break them down so that after a while, all you'll see is soft, spongy tissue.  The latter may eventually become so rotted/decomposed/broken down that bacteria can then break them down further.  Because fungi work so slowly, they don't create a lot of heat (fision related), so keeping them in the majority keeps the composting material from becoming so hot that the useful microbes are killed.

You'll note that, when I was discussing bacteria, I said the process needs aerobic bacteria, which require air.  Another type of bacteria is anaerobic bacteria, which are not viable in atmospheric 'air.'  If you've ever mowed the law and piled up grass clippings and left them, then returned in a few days and detected an odor:  what you smelled was ammonia, a gas exuded by anaerobic bacteria.  (Our colons are filled with trillions of anaerobic bacteria--and you know what they create!)

The way to keep a check on anerobic bacteria is to add air, which is why turning a compost heap is essential.  And most microbes need a moist environment to do their 'work' (eating and eliminating) so adding water is also essential.

That was a long-winded way of saying that you should add more "brown" materials to the manure, such as cardboard, shredded newspaper, shredded autumn leaves (once they are no longer green, much of the nitrogen is gone), straw, eggshells you've washed and pulverized in a blender, teabags (remove any staples) and their 'envelopes,' sawdust, 'clean' paper towels (you don't want to attract rodents if they contain food or oils) and hay.  You can, but don't have to, mix it with the manure and topsoil, because soil microbes in search of a meal will come up and often carry it back to subterreanean levels.  Ditto worms.

If you excavate soil from one place in the garden (or someone wanting to get rid of same), it's helpful to load that over the above, as it is an instant source of microbes.  And, so long as you don't overdo it, adding grass clippings, remaining structures from 'dead' plants, and kitchen scraps (reduced to the smallest size you can) will also be helpful.   If you provide food for the microbes, they will more quickly make the manure both at the nutrient level, and sufficiently composted that their salts (unhelpful to plants and some microbes) will have leached.  And the texture of the soil will have improved tremendously.  (You will get far more detail in "The Hidden Half of Nature!")

Sorry I'm so long-winded, but the strata we treat like dirt is both complex and invaluable.

One other thing, Adam.  Don't let anyone add tree parts from black walnut, butternut, English or Persian walnut or hickory trees, since they contain a toxin, juglone, that may persist for years and will kill many types of plants.  Kris

Thanks for all that great info on composting Kris! Much appreciated. I am clear now on composting and I will speak with The Woodland Trust who will be supplying our native trees to check which will grow in clay. I am still not sure though on how to best start preparing the clayey plot we have. We haven't got time to prepare all the compost required to cover it and we can't afford to buy compost as it is a large area. Can we keep adding lots of manure over the course of this year as we have loads of it to hand? Would this eventually improve the drainage? Could we mix it with brown matter or sand? Kindest regards, Adam

You don’t need to prepare the clay, Adam. The microbes are already working for you. But you don’t want to keep piling on manure. The salts will build up—even assuming adequate precipitation—and then the micro-nutrient balance will be off. If you want to be ‘doing something,’ you can wait until the ground is workable (not muddy) and use a pitchfork or a similar tool, and turn the organic materials into the soil. Rototilling is not recommended; it disturbs soil texture. And you don’t want to walk on it when wet; that compresses the soil and forces out air. Then, next fall, plant a cover crop such as red crimson clover or alfalfa, and let it grow over the winter. It will protect the soil from water compression and, in the case of legumes (clover, for example), return nitrogen to the soil. Just be sure to cut off the foliage before it goes to seed, or till it back into the soil. Great ‘green’ material. Spring’s almost here!

Thanks again for all your help Kris! Much appreciated, Adam