Fancypance
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What to do in clay?

I live on a lot that is pure clay and would like to start a veggie garden. I have heard that adding and mixing in sand is necessary for drainage.

Any suggestions?

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hendi_alex
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I think that in heavy clay adding sand and organic matter is essential. But IMO it needs to be done in the context of raised beds. If you add sand in a flat garden spot, all you are making is a basin that will hold water and form a mud puddle. With a raised bed, the excess water will drain from the soil and run off.

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Alex always has sound advise.
Or put all the leaves you can find on in the fall and dig it in deep.
Compost first sand second.

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rainbowgardener
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IMHO the organic material (eg the leaves that were mentioned ) is more important than sand. Dig in a whole bunch of OM (leaves, compost, manure, coffee grounds etc) and then till it all together. If you don't have a whole bunch of OM and want to plant this year, just build raised beds on top of your clay and fill the beds with good topsoil and add amendments. I have 16" deep raised beds on top of my concrete patio and stuff does fine in them, so it doesn't matter what's under your beds :)

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All good advice; I agree wholeheartedly...

HG

milifestyle
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Even when doing raised beds its a good idea to dig at least 10 -15 cm of compost into the top soil (clay). This will aid in future drainage and will prevent nutrient run off between the clay / compost layers.

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Good organic culture will start to open clay up; as fungal hyphae start to worm down into the soil they will open it up a tiny bit, roots follow and soon the bacteria and humic acids promote microaggregation that clumps the soil into lumps rather than letting it plate up , flake on top of flake (that's how clay forms...). Clay is just a pile of very fine grains of rock (we say parent material when we are being professional about it, but it's rock). In fact in most locales the difference between gravel, sand, loam clay and silt is mostly how fine it got ground. Mix some humus and biology in and everythingwill be just fine in short order. For that reason compost is a much better fix than sand; good call rainbowgardener...

milifestyle
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The Helpful Gardener wrote:Good organic culture will start to open clay up; as fungal hyphae start to worm down into the soil they will open it up a tiny bit, roots follow and soon the bacteria and humic acids promote microaggregation that clumps the soil into lumps rather than letting it plate up , flake on top of flake (that's how clay forms...). Clay is just a pile of very fine grains of rock (we say parent material when we are being professional about it, but it's rock). In fact in most locales the difference between gravel, sand, loam clay and silt is mostly how fine it got ground. Mix some humus and biology in and everythingwill be just fine in short order. For that reason compost is a much better fix than sand; good call rainbowgardener...
Would it also depend on the parent material it started from and the mixes of such material within an area?

I'm guessing "Bedrock" would produce more of a clay soil and "quartz" more of a sandy base.

Soil as a plant growing media is probably not needed much these days. On a small scale at least.

Planting directly in compost or a hydroponic system for the home gardener and larger scale hydroponic systems for the commercial operator are more environmentally practical solutions.

But nothing can take away the joy of digging in ones vegie garden :)

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Well much as we get different colored beaches you get different colored clays, different colored loams, and the changes in parent material cause different chemical properties and perhaps a tendency towards a sppecific size, but no, the soil texture (rock, gravel, sand, loam, clay and silt) are really just a function of mechanical action...water is usually the responsible agent for distribution at the surface, hence fine particled soils (clays and silts) are usually found around water...

And I'd have to disagree about the soil not being necessary; sure many growers are doing so in a soiless mix but more and more are adding back the soil biology with supplements; soiless is just not sustainable, and I'd say the same for hydroponics, with it's built in layer of mechanical support...soil is a precious resource that we abuse and dispose of callously through poor gardening and farming techniques and I'd say a major tenet of this site would be to get people to value and nurture that resource. It all begins with the soil, and it all ends there. If we all gardened organically, returning our waste streams to the soil, atmopheric carbon would not be an issue, soil erosion would be a thing of the past, flooding like we are seeing here in the Dakotas would be much ameliorated due to better porosity and holding capacities, the Dead Zones would clear up, and it seems likely we would see a decrease in many diseases like cancer (more data building daily on that front). Compost can't save the world, but it can keep it whole while we deal with the other stuff...

HG

milifestyle
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Yeah, I have no argument for any of that. Very well said.

In my previous reply I was considering the impact on soil erosion and similar environmental problems associated with repeated tilling etc.

I think hydroponics has its benefits however, & can be considered sustainable.

I remember a Nat. Geo. (Might have been Discovery) program once that showed how Hydroponics could restore growth, while feeding those in 3rd world countries.

A mindful gardener will always use sustainable techniques.

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Hydroponics certainly has its place in urban settings and I think that more and more urbanites ought to consider how to feed themselves. In that circumstance it has value. But it is water intensive and that won't suit a lot of locales and it does necessitate power sources (could be done with solar in the right climes) and therefore infrastructure that doesn't exist in Third World countries (who need these solutions right away...organics is a solution for everywhere (and repeated tilling is not part of sustainable organic culture; in NOFA we teach no-till systems as the best practice...)

We need to embrace our connection to the rest of the biota and a good place to do that is the soil. We can certainly find ways to work around soil, but I do not trust man's ability to replace every nuance that soil biologies bring to the table (as we have been doing for a hundred years) because, let's face it, the track record is bad. The Lancet's report of last year (on a decade plus long study) makes it very clear that raising your plant foodstuffs in organic soils raises nutrient density by an average of 25 to 30% with as high as 100% increases in root vegetables. I am no expert in hydroponics but do know a good deal about soil biologies and I would be interested to see a Soil Food Web biological assay on rock wool and nutrient solution. I'd bet the ranch and all the livestock that the soil is more fully active, in total biomass, total active bacteria, total active fungii, and most importantly, and I can't stress this enough, protozoal counts both numerical and by species. Microbial grazing by the higher level predators (amoebae, cilliates and flagellates) is where the poop loop starts and where nutrient etching from parent material begins, and to think that we could replicate those natural systems is hubris (and how we got in trouble in the first place).

Hydroponics has a role to play in places where access to soil is limited (urban settings, outer space, your closet in your college dorm room) but it is not now, nor should it ever be, a substitute for growing in soil. We have fooled ourselves for too long that we can do better than Nature, and it is biting our collective heinie in a list of ways already given here. Working within the natural framework gives us many benefits, and just as importantly, gives benefit to the rest of the biota at the same time. It is a system I can teach a farmer in Lagos or Vietnam or Iowa, and it works everywhere, with free, simple, inputs you can find in any country, no matter how rich or poor, with no need for complicated infrastructure. THAT is the kind of gardening and agriculture I can embrace as saving the planet...

HG

Fancypance
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Thanks, everyone, for the good advice about gardening in clay! This is all pretty new to me, and it sounds like raised beds are they way I will approach this, also considering my garden site, which is low to begin with.

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No doubt FP. You can regulate for too little moisture in a low spot by adding water, but there is no way to regulate for too much. Raised beds takes care of both ends of the spectrum, and allows you to tailor your soil to suit your needs...

HG

viviann
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I am a newbie here but would like to make a comment about raised beds too. I am plagued by one or two neighborhood dogs who like to visit my yard regularly. With raised beds it is a lot harder for this old and heavy beagle to climb in and make trouble. (I have treated wood around each veggie bed.)
And I think the added height makes it easier to harvest.
Viviann

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I might not use treated lumber as it contains arsenic and other impurities I would not want in my food crops, but I approve otherwise...

HG

viviann
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Hmm, I will check with my garden designer guy. I understood it was treated with salt.

The Helpful Gardener
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Glad to hear Viv, and there ARE salt treated alternatives in use, but the majority of "treated" lumber out there is chromium arsenate or other heavy metal combos, really bad for edible applications... sounds like your garden designer is on it...

[url]https://www.strongtie.com/productuse/ptwoodfaqs.html[/url]

Just trying to keep folks safe... :D

HG



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