Improve Clay Soil with Sand?


Hey again It’s Jason from Fraser Valley Rose Farm today I wanted to talk to you about whether it’s the right thing to use Sand to improve your heavy or clay soils now if you’ll recall I made a video about a year ago on how to improve heavy And clay soils and if I mentioned sand at all Maybe I even didn’t it really was a video focused on adding organic amendments and green mulches to the top of your soil things like woodchips compost manure leaf mold or again, green mulches like comfrey or alfalfa or cover crops and So I didn’t talk about sand in that video Particularly, but it came off in the comment section a lot of people came out and said well isn’t sand the best way to improve the texture of your soil and we had a good vigorous debate on that and I like that I like that we can try to sort this stuff out together so I wanted to go today and talk about the difference between Texture soil texture and soil structure The difference between soil texture and soil structure is so important so fundamental to soil science It was literally the first thing I learned in my soil science class in university perhaps even on the first day So soil texture is what you classically hear about when you talk about soil types It’s the sand the silt and the clay soil structure is an entirely a different thing, which I’ll explain in a minute But let’s go over texture first. If you will you will call those the Ingredients of your soil. They’re not the cake itself. They’re just like the flour the sugar of the eggs Okay, they determine what went into the soil, but not how it was baked So that’s the analogy I’ll bring forward here. So of course sand sandier soils are looser They have a lot more pore spaces. They’re gonna let the soil run They’re gonna let the water run through a lot quicker. They’ll have lots of air spaces in them, you know silty and Particularly clay soils are much much heavier, and they retain nutrients a lot more They retain moisture a lot more and they’re just heavier and stickier as soils so when we’re talking about sand silt and clay we really are just talking about the ingredients and soil scientists put gather soil texture triangle to show you how that’s going to work I’m gonna put up a copy of that on the screen here and maybe highlight a section here to show that at the very bottom end of this that’s going to include your Sandiest and siltiest soils, but at the top portion of the pyramid here It’s talking about your clay soils and you’ll see how far the line goes down. In fact anything down to about 20 percent clay Components in your soil has heavy or sticky characteristics of clay and by the time you get to 30 or 40 percent It’s completely dominated by clay characteristic Now if that told the whole story that was all you had to worry about was just what ingredients are in your soil This would be a much easier video I would be much more ready to just say okay tear up the whole lot put down a whole bunch more sand Grind it in with your rototiller. You’re golden the part that is not So clear-cut from that approach is that soil structure is something entirely different? That is how the cake is baked With all the air holes and all the the structure of that of that of that profile so if I dig out a section of soil Which I’ll do here you’ll see that at the top end of the soil. It has a lot more organic matters a lot looser it’s a it’s the part where the worms and the soil life are interacting with the organic matter and digging that into the top end of the soil and then as you move down through the soil profile the characteristics change it moves from being rather organic and it has lots of spaces and lots of soil life to an area that is Less so and then towards the bottom of your soil and even getting down deeper into the subsoil almost completely Lacking of those of those components, so it’s not homogeneous from top to bottom and those air spaces and the water Movement through that as well as the soil life and the organic matter Makes up a really really important component of what your soil performance is And in fact the way that it has settled like that the way that it’s been in there with the fungus and and everything Working in that soil. It’s like it’s a living profile all to its own and Once you go in there and you grind it up and you add a new component you and you make this homogeneous layer of like say 18 inches if you were going to of a new mixture of sand silt and clay Primarily you’ve completely disrupted what was existing and what was working and existing in your soil previously so to say that yes, you’ve changed if you if you increased sand and you’re in your soil that Changing that ingredient would change the characteristics. Absolutely But there’s a cost to doing that not only the cost and labor not only the cost in bringing in sand but the cost Immediately to the condition of your soil. So going back to that baking analogy. I made the Ingredients the sand the silt in the clay If you adjust that and you do that by grinding it up and putting in a bunch of new ingredients It’s a bit like and I’m gonna call this the pastry dough analogy So a pastry dough is a specially prepared dough that has all sorts of different layers in it and so when you put it in the oven and you bake it those layers that structure is is is baked in and so when I take a cut of profile of this what you’ll see is a very thick of airy pastry dough whereas if I take the same dough Same ingredients stick them in the in the blender or the food Processor in advance and just mash it up and roll it out and put it into the oven I’m not going to get the same results what I’m gonna end up getting is something that’s much much thinner and lacking all of those air spaces so the cost of putting in those new ingredients into your soil is a is much the same that you’ve you’ve basically completely interrupted the Existing structure of the soil in favor of trying to adjust those ingredients so the most contentious thing I may have to deal with in this video here is the allegation that you’ll have to add a lot of sand to your clay soil to make it better and Some of that comes from internet sources in one particular one. I will link below She’s a credible source. I’ve liked her stuff before Linda Chalker Scott PhD from Washington State actually who explains that because the clay will have to will fill in the pores between the sand you have to add an awful lot of sand to make the Improvement. I did a calculation myself. It didn’t seem catastrophic if I if I looked at a twenty by twenty plot of land so you’re doing a veggie garden say twenty by twenty and You wanted to amend it to about two feet and you’re trying to move the clay content from from forty percent Down to thirty percent so that you can get into the loam territory. I calculated that Depending on how you did it whether you removed material and then added some or whether you just heaped on a bunch and then till then you might have to add between 60 and 260 cubic feet of sand which yeah sounds like a lot of work It sounds like a lot of material but it’s not catastrophic by any means and if that gets you the results that you need Hey good on you My only focus of this video is to make you understand that that doesn’t happen without a cost and once again I’m not talking about the physical cost of sand. I’m not talking about the labor cost of putting in the sand I’m talking about every time that you dig your soil and you till your soil you sacrifice those fungal structures the life the the air holes and everything else you make this homogeneous layer of the Ingredients but it basically has to start all over again to get the the structure back that it needs to to to make great plant root systems So before you go ahead and try to add sand as an amendment dig in a big volume of sand into your garden I’d like you to consider some of the alternatives and I’ll point towards another youtube channel I think his name is Charles Dowding who doesa No-Dig Channel and I kind of like what he does there It’s a basically a sheet mulch that he uses with mounds of organic matter that he’s using on top of the native soil So it’s a is basically like a raised bed but without all those pesky wooden borders that eventually rot out on you and I can see the advantage of this because from that layer of organic matter He’s got on the top that layer of manure or compost that he has on the top the plants can establish good roots and will probably even Dig below that and get into the native soil Which is fantastic over time that addition of organic matter is going to improve his soil from top down and I think that’s a fantastic Approach. All right. Those are my two cents on Using sand to improve your clay or heavy soil I hope you found this useful if you have any questions or comments or debates or or rude remarks leave those below the video and I’ll be happy to answer those as well. Thank you so much

13 thoughts on “Improve Clay Soil with Sand?

  1. You should do a garden tour. I would like to know what the white flower behind you is? Off subject. I saw another YouTube video of someone who advised to plant your rose bushes deep to promote roots from the stems? Is this good advice?

  2. You didn't mention gypsum as a clay soil amendment. I learned my soil structures as a kid from Queen Victoria's gardener. An old, old book. Tilth, loam, composting. Layers and soil structure. Natural drainage and water retention and the importance of worms….

  3. Nice to hear you talking about soil biology and soil health! Thanks Fraser. And thank you for talking about your methods for rose propagation, I am enjoying experimenting with semi ripe cuttings

  4. Cover crops help amend soil. My radish are growing nicely. Sunn Hemp a legume is growing nicely too. The worms enjoy the cover crop roots and as a result aerate the soil. I have a few surviving oats that I broadcast. Oats should not be broadcast. I love my Barley. It has broader leaves than Sudex and Millet. I am growing all (3) Crimson Clover and Annual Rye make a nice root system. I have these planted as well.

  5. I live in California. If I add sand to the clay soil her, I may get adobe bricks to build my house.

    Sand will certainly improve your soil, but around here, it’s wise to question an improvement to what end.

  6. Hi Jason how are you. Hope all is well. I know I had asked you before about miniature Rose's. I'm really having trouble. They seem to die on me in a couple of days. I potted 4 in an adequate container put them in part sun part shade. Picked up another one "obviously there was a sale" and the blooms went brown and it also looks like it's dying. I didn't even have the chance to water it because it was already very wet. Any advice would be greatly appreciated. Have a great day. Thanks

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