Shop Products
Houzz Logo Print
ssmdgardener

The 'Perfect' Gardening Soil Structure?

ssmdgardener
12 years ago

I'm really interested in learning more about the science behind soils. I'd like to start a discussion about the best way to amend any ordinary yard dirt to make it the perfect growing medium.

Please let me know if I have the basics correct:

* There are inorganic and organic matter in soil.

* Inorganic matter consists of sand, silt, and clay.

* Sand is the largest in particle size, then silt, with clay being the smallest.

* There is an optimal ratio of the 3 inorganic materials.

* Organic matter, such as compost, leaf mold, or bark can be added to the inorganic matter.

* Some organic matter are preferred over others as an amendment.

* There is an optimal ratio of inorganic to organic matter.

* The ratio of amendments differs in the ground vs in a raised bed.

* The method of amending is important, as you don't want to disturb the creatures in the soil food web.

Please add any information that is missing, or if you disagree with something. I'm particularly interested in the best method for adding amendments.

FYI, this all started because I started out with not enough organic matter (rocky clay) and now I think some of my beds have too much organic matter, which I didn't realize could be a bad thing. I'm sick of trial and error, as that has only cost me money and time, so I'd like to learn the science behind it first.

TIA!

Comments (69)

  • Bob1016
    12 years ago
    last modified: 9 years ago

    The whole don't add sand to clay issue is a way of warning people to be careful when adding sand to clay. If you add clay and small grained sand, you get cement. If you add clay to builders size or larger (preferably 1mm), you get a water and nutrient retentive, yet well drained medium that works wonders. If starting from scratch in a bed, you most certainly can add clay and sand, just get large grained sand! I think the wording is bad, if you amend clay with sand, it won't work, if you amend sand with clay, it will most definitely work.
    Your mix looks good, but the turface is not necessary. Clay will retain water and hold nutrients, as will bark, turface too. I would go with perlite instead just because you don't want to retain too much water. The OM portion looks good, the greens and coffee will breakdown within the season releasing N and making the structure nice, while the bark will take a very long time to breakdown making the structure last longer.

  • jolj
    12 years ago
    last modified: 9 years ago

    A search on the net says from 5% to 45% on some sites in OM.
    I say you can not have to much organic matter as long as you can still see the soil & the soil structure in the mix.
    But before anyone told me, it would not work, I planted crops in 6 inches of rotten cow & horse manure for one of the best gardens, I have had in 30 years.
    But I have to much sand so this may not work for poor loom or red clay.

  • wayne_5 zone 6a Central Indiana
    12 years ago
    last modified: 9 years ago

    Loam is a mixture of sand, silt, and clay. If your clayey loam soil already has some sand in it, How can adding some more sand of the right kind hurt it? Perhaps only western adobe clay might have trouble, but I would expect even that to work if sufficient OM like peat moss is added at the same time. I tell you....my mix of different size sand particles and local peat moss to my clay loam is wonderfully scrumptiously a delight in all ways.

  • wayne_5 zone 6a Central Indiana
    12 years ago
    last modified: 9 years ago

    Loam is a mixture of sand, silt, and clay. If your clayey loam soil already has some sand in it, How can adding some more sand of the right kind hurt it? Perhaps only western adobe clay might have trouble, but I would expect even that to work if sufficient OM like peat moss is added at the same time. I tell you....my mix of different size sand particles and local peat moss to my clay loam is wonderfully scrumptiously a delight in all ways.

    ssmdgardener, The eastern soils have been tilled for a long time and likely are leached of many minerals.....Leonardtown loam and Norfolk sandy loam might be examples of that. These soils probably need lime and micro minerals and lots of OM.

    I hope I am not double posting this, but don't want to chance losing this if not double posting.

  • strobiculate
    12 years ago
    last modified: 9 years ago

    The is no such thing as a 'perfect' soil structure, because we have so many different uses for soil.

    What works to support a building would not necessarily be good for a road, or a bridge, or agriculture. The soils that grow great sugar beets would not be good for potatoes. So there is no one "right" answer.

    So you want to learn about soils...

    First, soil science is an exercise in engineering. Second, it's a practice in planning. It's much farther down the road that we get into agronomics.

    As far as when it comes to growing things in soils...

    Soils are by far the most complex part of the equation of growing plants. They are by far the least understood.

    And to a certain extent, how much you know or what you know isn't that important.

    Take your question, for example. To a soil scientist, the structure of a soil is more about it's engineering capacities than how to get a decent flower garden to grow. One question, two entirely different answers, each based on the perception of the person providing the answer or asking the question.

    So what is the perfect garden soil? How much organic matter is to much? If there such a thing as too much organic matter, all the fans of lasagna/layer gardening would be up the proverbial creek, and that's before we get to hydroponics. It's less about the growing media, and more about how you manage it.

    You've got perhaps the most difficult situation of all. A layer that is virtually impenetrable and relatively shallow. The "easy" answer is raised beds. The adventurous answer is explosives. The practical answer? There are far too many questions to be asked and answered before we can even get there.

  • toxcrusadr
    12 years ago
    last modified: 9 years ago

    Adding sand to clay is all about the amounts (as well as the particle size of the sand as was mentioned earlier). A tiny amount won't be noticed. A little more, concrete ensues. Beyond that, after a certain point, the sand grains are numerous enough to begin touching each other amongst the clay matrix, which begins to hold the structure open. So it's not "don't add sand" but rather "beware when adding sand."

    One suggestion...nothing wrong with starting this thread, but I hope you are also *reading* many of the others here in which these issues have been discussed by these and other smart people. [I do not include myself :-]

  • Laurel Zito
    12 years ago
    last modified: 9 years ago

    I knew my native sand was too fine to add it, and so I bought special horticulture sand that was at at the perfect size grains. They even sell these little bags anymore, I bought out all they had at osh, so even with the right size sand, it still did not work out as I would like it. The soil is ok, but it is much harder then it should be. Now, I can't actually take out the clay, so I am just dealing with it. If I could do it again, I would have omitted the clay. It a good soil, but its a bit heavy on some plants vegetables that would be better off in a lighter soil.

  • bi11me
    12 years ago
    last modified: 9 years ago

    tropical thought, have you considered adding crushed bark or perlite? I grow sunchokes, which are in the sunflower family. The shredded stalks are a great soil conditioner, but they don't last much more than a year.

  • organic_popeye
    12 years ago
    last modified: 9 years ago

    Dear ssmdgardner, please visit the first two threads, The mystery of HUMUS and Soil testing - why do it? I posted on there extensively and we are having a lively discussion. I use an integrated system emphasizing humus production, adding mycorrhizal fungi to my soil and complete soil testing. The results are phenomenal. I don't till anymore and my soil structure has improved so well that at first I couldn't believe it. I am using new organic technology that has happened within the last 10 years and especially the last 5. Current research is rewriting the textbooks. Also, I cordially invite you to check out my educational website, thedoublevictorygarden.com. Best to ya and good growing. Your statement that you don't like trial and error really got my attention. I hate guessing - I generally research anything that I want to use thoroughly before trying it.

  • ssmdgardener
    Original Author
    12 years ago
    last modified: 9 years ago

    Organic_popeye, I've been following the other posts with interest. It's great to learn about recent research, but I'm still unclear on practical applications.

    -How do I incorporate mycorrhizal fungi into my rocky, hardpan clay without tilling (and digging out the rocks/boulders) at least once?

    -You said in the other post that we can't talk about products. But is that true? I've seen discussions of products here before. What are the products/methods you use to incorporate mycorrhizal fungi?

    -What is the effect of using these fungi in the ground vs raised beds vs containers?

  • ssmdgardener
    Original Author
    12 years ago
    last modified: 9 years ago

    Popeye, I have one more question.

    Isn't the soil structure still important? You could have all the mycorrhizal fungi you want, but if the soil structure (pure sand, not enough organic matter, etc.) isn't good enough to support plant life, then you still have dead plants. Right?

  • Laurel Zito
    12 years ago
    last modified: 9 years ago

    I used to have pure sand, but somehow before I started to use OM, I did have some limited success with a few plants. It is amazing that plants can live without any soil amending, but won't be at their best. I had some bushes that did ok. Re mycorrhizal fungi if you use wood product in your composting system or even a mulch of mircobark will encourage fungi.

    Yes, I did add a lot of perlite, you can even see it there but still it is a bit on the hard side. I think over time with more OM, I will improve it. I can only add so much OM at one time as I have reached the top of the box. Or I could remove some of it and distribute it around my garden were it will not be so concentrated. I can bear to discard it, because that sand was hard to get.

  • ssmdgardener
    Original Author
    12 years ago
    last modified: 9 years ago

    Tropical, I wonder if that's why hugelkultur is supposed to work so well... does all that decaying wood invite mycorrhizal fungal action? What if I buried tree trunks/woody materials in my raised beds?

  • ralleia
    12 years ago
    last modified: 9 years ago

    To get the mycorrhizal fungi into the soil, the usual technique is to dust your transplants' roots with the fungi in dust form and then plant out as you normally do.

    I've read some techniques dealing with drilling a hole in the ground and pouring in, but in your type of soil I wouldn't do it. They need somewhere hospitable to live first.

    And it's not just about micorrhizal fungus, either, nor is it just about fungi. It's about bacteria, and a whole range of insects and arthopods, and about plants, and especially about earthworms!

    If I had a lot of compressed, cracked, unworkable clay with big rocks mixed in I would probably do the following. (I do have quite a bit of compressed, sometimes cracked and unworkable clay in one area of the gardens).

    1) Plant a taprooted annual cover crop to "drill" holes in my clay. The deeper-rooted the better. I've been thinking about trying to rent a seed drill to help get the seed situated in the compressed clay. (If that will even help).

    2) Once it reaches maturity, kill it and mulch it. The roots slowly decompose, leaving holes in the ground for improved drainage & infiltration. The mulch helps support all the types of soil life that are required to improve the structure and composition of your soil.

    3) Repeat steps 1-2 as many times as necessary to start to feel the structure of your soil improve, and it will. You can also rotate different types of cover crop.

    For the winters I would be sure to have that soil covered with a dense cover crop that will perish over the winter to protect the soil from erosion and shelter soil life.

    When I was preparing the soil in my hoophouse (it had originally been bad sod and weeds) I did three successions of buckwheat, mainly because it was a warm weather crop that I could grow quickly during summer in the hoophouse.

    Peaceful Valley had a really good matrix for choosing cover crops for different goals, but I can't find it online at the moment. I've got soils homework to finish now, but once I'm all done I'll either find an electronic copy or upload a scan.

  • bi11me
    12 years ago
    last modified: 9 years ago

    ralleia makes some excellent points, to which I would only add this - mixed cover crops, such as a blend of radish, clover, and alfalfa, will have a much faster beneficial effect on improving the tilth of clay soils. Successive cover crops, incorporated by mowing and leaving the residue as a mulch, will accelerate the biotic activity in the upper soil layers. A final shallow tillage will be all that is needed to easily start your crops in highly productive soils.

  • Laurel Zito
    12 years ago
    last modified: 9 years ago

    I have never done hugelkultur but since I use a wood mulch instead of a lawn, and it's microbark I get a lot of mushroom growing. I can see the white lines of the fungal bodies if I start to dig in the areas in which I have wood clips as mulch. However on the downside wood ties up the nitrogen and some people don't think plants are as healthy when placed in a wood mulch to keep weeds down. But, the nitrogen is only tied up briefly then it is returned. If you listen to a radio show called "you bet your garden" the host only uses peat moss and no wood. So, each expert has thier own opinion.

    I think what people are talking about are extra fancy things you can do with your soil once you have your basic soil composition worked out to your satisfaction. There is no magic bullet to make a bad soil perfect other then time and work and OM. Some people just look at clay and give up. It is a lot of work and digging. Eucalyptus wood has oils that impede the growth of other plants. Foreign woods that one bring to thier garden may host diseases. Someone here on this forum mulched with some wood that made all his trees die.

    Some people don't even like to add organic matter to clay. There is a case for this position also and a thread about it called The Myth of Soil Amendments. The theory is it is a bad to add OM to clay for trees. I think OM it would be ok for small little plants like pansies in clay. But, since I never tired it out, I don't really know. I have a cut down stump from a tree that I am letting decay slowly. It does seem to help the nearby soil a bit. Is wood good for clay? This would be the question to ask and have answered before trying hugelkultur.

  • ralleia
    12 years ago
    last modified: 9 years ago

    This youtube video shows a mixed cover crop field of "groundhog" radish, chickling vetch (nitrogen fixer), and Austrian winter peas (nitrogen fixer) similar to what Bill is suggesting. It shows some of the difference in soil compaction that can result from using cover crops.

    Radish +vetch & peas cover crop result

    I found the Peaceful Valley Cover Crop chart, but on closer inspection it doesn't speak very well to drilling holes in heavy clay. It's a decent resource for a lot of other cover crop applications though: PVFS cover crop matrix

    Take a look-see at this marketing document on "Tillage Radish." Tillage Radish doc with great photos

    Take it with a big grain of salt of course, since it *is* designed for marketing, but it has some excellent photographs explaining the concepts of why some of us with compacted soil might want to use taprooted plants to drill into heavy soils.

    I've never tried tillage radish, but in my compacted clay soils, taprooted perennial weeds like curly dock, dandelion, and common mallow flourish. I've been trying to beat them back for years, but since I've not replaced them with anything taprooted to do the soil work, I think that my soil structure is deteriorating. The tomatoes didn't do well at all last year. So this year I'm going to obtain some form of freeze-killed radish cover crop to start regular planting in that area.

  • ralleia
    12 years ago
    last modified: 9 years ago

    Oops. Got carried away with quotation marks on the radish document link.

    I'll let gardenweb handle it:

    Here is a link that might be useful: Tillage Radish

  • jolj
    12 years ago
    last modified: 9 years ago

    ssmdgardeber, good to here from you again.
    Have you tried trench composting?

  • ssmdgardener
    Original Author
    12 years ago
    last modified: 9 years ago

    Hi Jolj, it's just so darn hard to dig in this clay to do trench composting. I think it took me 3 hours to plant about 15-20 bulbs. They were muscari bulbs, only needed to be a few inches deep, but I had to dig out all the hardpan and all the rocks and amend the soil a few more inches. It was exhausting.

    And the squirrels/cats LOVE the amended beds, because it's less work for them. :/ I can imagine they'll have a field day if I buried anything worth composting.

    I don't have it in me to dig in this dirt anymore, unless I do some sheet mulching first to soften the clay. Whew, I'm tired just thinking about it.

  • ralleia
    12 years ago
    last modified: 9 years ago

    ssmdgardener--let the radishes and the earthworms do all your digging for you!

    A human can be pretty strong, but compared to a thousands of radishes and a million earthworms? Psaw. We're puny.

    Let the plants and the critters soften and work your soil for you. Become the benevolent master of your own little kingdom of millions of busy organisms. :)

    That's my plan for the acre and a half of compressed clay that I have. It's slippery and sticky when wet--cracked and cement-like when dry. My hands and wrists have chronic overuse injury from swinging a mattock too many months. Now I'm going to enlist help.

  • wayne_5 zone 6a Central Indiana
    12 years ago
    last modified: 9 years ago

    ralleia,
    That is quite a download on tillage radishes. I was going to link the video by Steve Groff also, but it may have been removed.
    I liked the larger size I got from some planted about August 1st, but that isn't always feasible with many crops.

  • jonhughes
    12 years ago
    last modified: 9 years ago

    Hi ssmdgardener,
    You have a lot of good info here, and instead of repeating all of the normal disclaimers... lets just say they all still apply ;-)

    Anyway... FWIW and YMMV :-) This is what I did, and it really works for me....Yada Yada Yada !

    As you have said "Hand Digging in Clay sucks" (I paraphrased your remarks ;-)

    For a couple hundred bucks you could rent an excavator and add enough Decomposed Granite to comprise 35% of your Medium, Pumice 20% Finished Compost 20% Clay 25%

    Decomposed granite is a rock powder and is an excellent amendment for clay soils. All rock powders are great sources of minerals and micronutrients. All growing soils need them. As the microbes and macrobes like earthworms, digest the insoluble minerals, they break down into the various soluble micronutrients that all forms of plants need.

    For example, limestone rocks are rich in calcium. Granite rocks are rich in potassium, etc. Seaweeds of course are the king of micronutrient fertilizers and soil amendments. There can be up to 70+ trace elements in seaweed. In locations where seaweed is not readily available; rock powders is one answer to the problem.

    Research continues to reveal that insoluble tiny particles like rock powder minerals, can be easily digested or absorbed via microbial activity, over time, into the anatomy of growing plants, thriving in the presence of rich organic compost, and other forms of powerful biostimulants like aerobic compost teas.

    Obviously a heavy clay soil is very difficult to initially dig, whereas a sandy loam is much easier. Heavy clay soils can be improved considerably by adding a lot of mason's sand. DO NOT use beach or river sand! Mason's sand, being crushed granite, has sharp edges and actually loosens the soil.

    One of the least understood aspects of gardening is that of capillary action of the garden soil. It is a proven fact that compressed earth has a better capillary action than undisturbed soil. That is why gardening books tell you never to walk between rows in a regular garden, as that encourages weed growth. And of course people are told never to step in a French Intensive bed and thus compress the soil.
    But the capillary action is absolutely necessary to bring water up to the roots of growing plants to promote good and deep root growth. In regular garden rows, it is easy to roll a heavy 2 or 3 inch wide weighted wheel (mounted on an axle and handle) down the row directly over the freshly planted seeds, which will then promote deep root growth along that line. The spaces between the rows are than rototilled to eliminate footprints prior to the initial watering.
    The basic concept of French Intensive gardening is that raised beds are created which have humus added, and the whole bed is light and fluffy to a depth of two feet to promote fantastic root growth. The beds are typically 4 feet wide and 12 or more feet long, with 3 foot paths between the beds.

    {{gwi:23538}}

    {{gwi:15885}}

    {{gwi:54997}}

    {{gwi:262979}}

    {{gwi:30700}}

    {{gwi:257829}}

    {{gwi:262984}}

    {{gwi:8599}}

    {{gwi:12770}}

    {{gwi:31555}}

    {{gwi:31558}}

    {{gwi:15175}}

    {{gwi:11399}}

    Here is a link that might be useful: How to build a raised bed that will last forever.

  • ssmdgardener
    Original Author
    12 years ago
    last modified: 9 years ago

    Wow John, that's pretty incredible. Now I'm craving a salad in the middle of the night. I'm assuming builders sand, mason's sand, and crushed granite refer to the same/similar things? I just have a small back yard and couldn't justify renting a tool to excavate, even though I b!t@# about hand-digging. ;-)

    ralleia, thanks for the pdf link. I already sheet mulched most of the areas that will be turned into perennial beds, but there is one last area, about 10x3, that still need to be prepped for next year. However, it's very shady. Would the radishes still work? Also, this area will be for perennials, not food crops. Would the radishes still be cost effective, compared to sheet mulching, which is pretty much free?

    Last year, I tried planting seeds of clay-friendly natives that are supposed to break up the soil, but they had incredibly shallow roots in the unamended clay. Those pictures of those radishes were pretty awesome.

    I haven't even started on the raised beds, but I'll just be placing cardboard on top of the grass and filling it with the soil mix, which I'm working on...

  • Kimmsr
    12 years ago
    last modified: 9 years ago

    Cornell, the University of Wisconsin, and several others will tell you that you should not add sand to clay unless you can add 75 percent sand to that clay. Purdue, Michigan State, North Carolina State, and several others will tell you that you need to add 45 percent sand to clay. Anything much less then 45 percent can create more problems than that would solve.
    Tropical, loam is one type of soil. It is about 45 percent san, 25 percent silt, 25 percent clay and 5 percent organic matter. The only really changeable part of that is the organic matter which is digested by the Soil Food Web to feed the plants growing in that soil. Plants can grow in soils lacking organic matter but most will not grow very well. Without sufficient amounts of organic matter in soil the Soil Food Web, including mycorrhizal fungi, will not function well. Dumping some "stuff" that contains fungi into soils lacking sufficient levels of organic matter will,largely, be a waste of money since those fungi, that need some organic matter to live on, will not have a nutrient source to pass on to the plants they extablish that symbiotic relationship with.
    The "perfect" garden soil is the one that your plants grow srong and healthy in.

  • Laurel Zito
    12 years ago
    last modified: 9 years ago

    kimmsr is right about everything he said. I just wanted to add, I think the perfect soil is one that is easy to weed. When I was first starting out I had hard packed fine grained sand. It was not possible to weed it. If you pulled the weed the top part would break off and the root would stay in. It was too hard to use a tool to dig out the root and there were too many weeds. I got hand pain from weeding. Now that I have lots of OM, I can pull a weed and it will come right up with the root provided it has not be allowed to mature. My soil no longer has tons of weeds seeds because I got right on top of each weed and removed it before it went to seed. I used to hate weeding before I solved this problem. I let it go on for years with weeds making seeds. Now all I do is take a daily quick look to remove any new weeds, it takes less then 5 minutes.

  • bi11me
    12 years ago
    last modified: 9 years ago

    I am not in full agreement regarding the practicality or advisability of the addition of sand to clay. In bordered raised beds, or in gardens of limited size, it is not unreasonable to amend clays with sufficient sand of the proper consistency. It is when one begins contemplating large areas that the physical and financial obstacles become prohibitive and impractical. In a series of raised beds, incorporating coarse crushed granite to clay-based mother soils is unlikely to cause any harm, and would, over time, have a noticeable effect on tilth and drainage and compaction without being too onerous a task.

  • wayne_5 zone 6a Central Indiana
    12 years ago
    last modified: 9 years ago

    jon,
    Good point about capillary action. I am not afraid to walk some on good amended soil as it does not really compact....bad soils, not so much.

    Kimm, I think you should amend your recommendation on adding sand. It should read: Add sand until it reaches 45% sand content, not add 45% more...as any loamish soil already has some sand in it. I would not want that 75% either that you mentioned.

  • TheMasterGardener1
    12 years ago
    last modified: 9 years ago

    My friends succulents are planted in stones and sands then he feed with compost teas here and there. The rest of his garden is in soil that is clay/rich matter.

  • jonhughes
    12 years ago
    last modified: 9 years ago

    Hi ssmdgardener,
    KIMM's % is probably fine, but I use 35% Decomposed Granite and 20% Pumice, so that's 55% and my soil is a literal dream, I can simply use my hand (no tool) and dig down to my elbow. So...my previously posted percentages work very well.
    With the addition of my awesome compost, I am totally blessed.

    {{gwi:262992}}

    {{gwi:90905}}

  • bi11me
    12 years ago
    last modified: 9 years ago

    Jon, the pictures you post and the purpose of your gardens are truly an inspiration. It would be a privilege to visit and work in your gardens, to observe your practices and to support the work that you do.

  • jonhughes
    12 years ago
    last modified: 9 years ago

    That's funny Bill, Because I was thinking about visiting your site. After the clear and concise replies you have made to several posts, I feel I have come to understand a little of what you do......though ( you wrote to one person recently that they will have to "wait and buy the retirement book" . I hate waiting... I want to see now ;-)

    {{gwi:62405}}

  • Laurel Zito
    12 years ago
    last modified: 9 years ago

    I looked up Decomposed granite on wikipedia and it seems that it turns into sand clay or silt over time, but it does not say how much or which one it will turn into.

    DG, is granitic rock that has weathered to the point that it readily fractures into smaller pieces or chunks of weak rock. Further weathering produces rock that easily crumbles into mixtures of gravel, sand, and silt-sized particles with some clay. Eventually, the gravel-sized particles may break down to produce a mixture of silica sand or silt particles and clay.

  • wayne_5 zone 6a Central Indiana
    12 years ago
    last modified: 9 years ago

    Jon, What is the texture of your Decomposed Granite? Is is gritty or fine? Where do you get calcium and magnesium from?

    I too like a loose garden soil for most things. I have one part of one wide bed that is sandier than the others. I do not see it as any more productive than the others.

    I can only take a rough guess on what my amended beds are....40% sand, 45% clay, and 15% silt for the mineral percentages......20% OM

  • jonhughes
    12 years ago
    last modified: 9 years ago

    Hi Wayne,
    I watch them scoop it right off of the ground, it is literally mountains (1000' high) and they are sticking in sticks of Dynamite and shearing off 1' wall at a time and then they scoop it up and load it on trucks, because of that, it is every size ...1/8" to dust
    PS...I'll go snap a picture...Be back in a minute ;-)

    {{gwi:68671}}

  • jonhughes
    12 years ago
    last modified: 9 years ago

    Wayne wrote: Where do you get calcium and magnesium from?
    I have no idea !
    I've never used any "fertilizer", but I keep hearing that it could really boost my production, so I am contemplating it. The only reason's I hesitate at all is :
    1. I am relatively lazy (if it ain't broke,don't fix it...mentality).
    2. It is expensive, and since I donate all of my veggies to the Food Bank, I just don't want to spend extra money, on something that I am not convinced will far outweigh the cost of implementing the procedure. I have 1379 square feet of garden beds and donated 9173 lbs last year (not counting what we ate) probably close to 7 lbs per foot , could I really get more by fertilizing... I just don't know... Maybe I will try a bed or two and see if they produce more, I may be pleasantly surprised and it will be worth the extra cash outlay.

    PS. The Rock Quarry wasn't open... I'll go back later ;-)

    {{gwi:15174}}

    {{gwi:23511}}

    {{gwi:23508}}

    {{gwi:107273}}

    {{gwi:65356}}

    {{gwi:110286}}

    {{gwi:119017}}

  • wayne_5 zone 6a Central Indiana
    12 years ago
    last modified: 9 years ago

    Jon, You are doing a beautiful job there and God bless.
    With the Decomposed Granite and Pumice you are getting a lot of micro and macro minerals. I am thinking that granite doesn't have much calcium or magnesium? Pumice might?

  • Laurel Zito
    12 years ago
    last modified: 9 years ago

    I am also interested in your Decomposed Granite and Pumice, so post us photos. I may get a little bit to experiment with, but it may be hard to find in san francisco. The only feed store is out in half moon bay.

  • jonhughes
    12 years ago
    last modified: 9 years ago

    A mountain of DG (Decomposed Granite)

    {{gwi:263004}}

    {{gwi:263006}}

  • jonhughes
    12 years ago
    last modified: 9 years ago

    Processed pumice is today used in horticulture, but unlike a superficially similar material, perlite. But extensive research conducted in Hungary in recent years has demonstrated that it can optimize moisture content in farm land, provide trace elements and boost the immune systems of plants, whilst reducing potentially harmful nitrate levels in the soil. If applied along with an organic nutrient, processed pumice can increase yields significantly compared to chemical fertilizers - and at a lower price.

    Agricultural Pumice 3/8" to 1/4"

    {{gwi:263009}}

  • bi11me
    12 years ago
    last modified: 9 years ago

    My area has several defunct granite quarries where people can shovel as much as they want, and screen it to a suitable size. There are also commercial operations that do this. You don't want to pay to have it shipped, it is very heavy.

    Wish we had some pumice nearby.

  • jonhughes
    12 years ago
    last modified: 9 years ago

    No doubt Bill, It wouldn't pay to ship it,,,Yeah , I count my blessings each and every day, and try not to take it for granted !

  • organic_popeye
    12 years ago
    last modified: 9 years ago

    Hey ssmd, Boy, its all here. Posts with opinions from everyone.

    Observations from my chair - adding sand to clay soils is labor intensive, not necessary and further, by itself doesn't work. Humus, Humus, Humus - Mycorrhizae, Mycorrhizae, Mycorrhizae - soil test, soil test, soil test.

    Products - Soil Secrets Terrapro, 94% REAL HUMUS + helper bacteria and mycorrhizae. Protein Crumblies, balanced food for the Terrapro helper bacteria. Liquid Earth Nectar and Earth Ambrosia once a month during the growing season, which gave more humus and biologics. All wild plants (I hate the term weeds) were pulled and dropped creating my own mulch. That has been my program for my 2010 and 2011 start up gardens on two separate locations here in Cochise, Arizona. I put these materials on top on my ph 8.8 and ph 7.3 concrete soils, watered them in, shallow planted and applied a 1" mulch. I did no tillage of any kind and no raised beds! All beds were at ground level. Virtually all of the foods grown had flavor that I can't remember tasting in any of my gardens since 1977. Some were close, but not as good. In 2010 a professional documentary film crew spent a day in the garden and we shot a how to and demonstration film titled, "The Double Victory Garden". You can get it on the web but I decided not to market it myself because it did have some minor errors that I wanted to correct. I am anal about these things.

    The 94% humus (confirmed by lab analysis) in Terrapro primes the soil pump providing a powerful negative charged energy field which attracts and holds the positive charged nutrients, Ca, Mg, K. etc. mentioned in the "Soil test - Why do it? and the Humus (OOW) threads". One molecule of "Supramolecular" Humus can attract and hold for plant use over 10,000 water molecules! The negative charge (CEC)of sand(least), silt (more), and clay (most) on the CEC (Cation Exchange Capacity) scale rarely is over 30. Compost generally runs 25 to 75 (if well made) and Supramolecular Humus is up to 250! The compost provides slow steady release plant food and that is its value. It only provides a max of 5% humus, that is what the new research proves. If you doubt this, have your compost tested and I don't mean an organic matter test, I mean a HUMUS test! The more alkaline the soil is, the higher the CEC of the humus - No need to try to change the ph, the humus adjusts to it whatever it is. Humus is the great fixer - It adds body to sandy soils and with Ca and Mg will aggregate and open up heavy clay soils so they can breathe. Universal fix-all! Nature can make ideal soil as mentioned but we have to provide the right inputs. When I started, I had to stand on my soil probe to get in an inch. 3 months into the season I could sink it in over a foot but this was in the beds which had received drip irrigation. A month ago when the soil in the beds was dry, the probe still easily went in over a foot! That impressed me.

    Jon, awesome garden! It obviously reflects your dedication and your hard work. I am not a market gardener, I am a researcher, experimenter and grow for the family I live with though I have sold some excess.

    Please visit my website, thedoublevictorygarden.com and Soilsecrets.com for the full story. On my site I have a before and after soil analysis for the 2011 garden. You might want to take a look. Blessings to us all.

  • bi11me
    12 years ago
    last modified: 9 years ago

    I know money doesn't grow on trees, but I'd sure like to know what variety of broccoli you're growing.

  • lazy_gardens
    12 years ago
    last modified: 9 years ago

    The "perfect soil structure" ... for what plants? You can kill some plants with the same soil in which others thrive.

    So first you need to figure out what kind of dirt you have, then decide what you want to grow, then decide if it's worth the hassle to make the dirt fit the plant.

    There are many plants that would grow here based on the temperatures - but they need extremely organic, acidic soils. I have alluvial desert dirt ... lacking organic matter, extremely alkaline, and on the clay side. It would require extreme measures to make the soil "perfect" for them. So I don't. I grow things that prefer my dirt, or that prefer the kind of dirt that is within my reach with limited amounts of fertilizing and amending.

  • ssmdgardener
    Original Author
    12 years ago
    last modified: 9 years ago

    Thanks to everyone for this wonderful learning experience!

    Wayne and Jon, it's interesting how your gardens have responded so positively to locally sourced ingredients (Wayne's peat moss and John's pumice and decomposed granite).

    Leaf mold, coffee grounds, compost, and pine bark fines are "perfect" organic materials for me, partly because they're so readily available and cheap and/or free. I do wish there was a local source for inorganic materials besides clay. I'm still leaning towards adding coarse builder's sand to the new raised beds, being careful of the right sand/clay mix. I'd love to try those clay busting radishes, but the area that needs it the most gets very little sun.

    Thank you all for teaching me about mycorrhizal fungus and humus. I'll be doing experiments this summer using MF and will post the results here!

  • wayne_5 zone 6a Central Indiana
    12 years ago
    last modified: 9 years ago

    I don't think that it is the variety of broccoli that Jon raises so much as the soil and such. My late fall crop of broccoli this past fall had heads 11 inches across right down the row...and they were extra delicious...commented on. I like Emerald Crown and Imperial best of the large number of varieties trialed [Stokes Seeds].

    ssmd, I added sand to clay loam but also added local sphagnum peat moss at the same time in equal amounts. Both amendments are basically making the texture and structure better and they are very very long lasting. Even though the peat is nearly all OM, I add other OM ....definitely as the peat OM is not a very active OM. I just love the results and the plants do too.

  • macthayer
    12 years ago
    last modified: 9 years ago

    I was in despair of growing anything in this one garden bed. It was lovely, surrounded by retaining walls, nice placement. But nothing grew, and I had a soil test done. Basically I had alkaline sand, with poor nutrients, that was the leftovers from excavating the house. It looked like hardpan. Sure didn't look like it had any clay --- just impossible to dig hardpan. I'm only 5'2", 108 lb, and under no illusion that I was going to dig it out myself. So I hired my landscaping company to take a foot off the top, and then loosen up what was underneath by another 12 inches. I couldn't do raised beds, but by digging down, essentially I created my own form of enclosed bed. I had them stockpile some of the sand, nice coarse stuff. Then I started layering, I worked as much compost into the loose sand as I could. Then I got "planting dirt" which you're supposed to mix 2 parts sand with 1 part planting dirt, but I mixed 3 parts sand to 1 part planting dirt because I had so much else to add. I mixed this up on a BIG tarp, and when that was mixed, added compost, kelp meal, bone meal, blood meal, mineral fertilizer especially for desert gardens, iron supplement (test showed a significant lack of iron in the soil), a bit of epson salts and a bit of phosphate to help with uptake of iron, That was spread out, and more and more mixed until I had about 24" of the stuff, (plus the 12 inches of loosened harpan mixed with compost) with room to add more on top. I'll want to add shredded bark once it's planted, and next year, another layer of compost.

    This is my own composition, based on decades of gardening, careful observation, lots of research, a soil test, and abounding hope.

    Just want to point out that I was VERY careful about the amounts of additives I put in (bone meal, blood meal, iron supplement, etc. etc.) and never exceeded recommended amounts, and in most cases, actually went under a bit. I can always add fertilizer, but once there, I can't take it out.

    The new soil test isn't back yet, but I want to make sure I haven't messed up the pH before I plant anything.

    Does anyone think I did good? What would you have done differently?

    I have another bed to go, so now is the time to correct me!

    Thanks!

    MacThayer

  • art_1
    12 years ago
    last modified: 9 years ago

    Around here we have two varieties of decomposed granite available - blue and gold. Which is preferred for soil?

  • organic_popeye
    12 years ago
    last modified: 9 years ago

    Humus produces superior soil structure and its absence or low levels in our soils is the reason why soil structure is so poor. Humus is the universal fixer - it opens up clay soils and gives sandy soils more body so everything doesn't leach down and away. It also provides the strongest negative magnetic energy charge to prime the soil nutrient pump. Getting more humic substances into our soils as rapidly as possible is the answer. I have already mentioned the benefits of well made effective humus products, good soil testing and mycorrhizal fungi. Roughly 98% of the humus in our soils is the result of mycorrhizae, not compost or mulch. As stated before, compost and mulch are food for the soil Food Web so will be consumed and must be periodically re-applied. In decades past I used to wonder where my compost went in only a month or two after applying it heavily to my soil. The answer is that the Soil Food Web ate it all up! Except for some coarse OM, I couldn't find it and my soils didn't get any darker. Bottom line? I wasn't building humus rich topsoil.

    Inputs on top are effective and this is how I do it now. Nature has been doing it that way for roughly 450 million years, so why should I try to one-up this marvelous system? With the new humus products I keep referring to, my soil has opened up and gotten good structure in months, not years.

    Success for all growers is paramount and is especially so for NEW GROWERS. I feel that they need to have good results from the opening gun so that they don't get discouraged, give up and quit growing.

    Many of the suggestions listed above about blending sand with clay, creating various soil mixes, etc. are, from my chair, labor intensive, expensive and not necessary. Work with what you have. By the way, the only reasons that I would make raised beds is for convenience, low poor drainage soils or if a gardener can't get down to the soil level because of poor health. Nature doesn't make raised beds so why should we? I have had excellent success working at natural ground level.

    Here is a link that might be useful: The Double Victory Garden

Sponsored
2 Navy Lane, LLC
Average rating: 5 out of 5 stars18 Reviews
Loudoun County's Leading Interior Designer