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Author Topic: clay soil amendments?  (Read 299 times)

brian

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clay soil amendments?
« on: September 10, 2017, 10:01:18 AM »
As my greenhouse construction progresses I'm starting to think about soil.   I intend to plant trees directly into the ground inside my greenhouse.  My soil is clay but not too hard - the topsoil crumbles under hand pressure.  The dirt on my greenhouse floor is loose right now because it is recently excavated from the foundation trench.   I have an opportunity now to amend it, and/or shape it to affect drainage.   Any suggestions? 
  • Doing nothing at all may be a viable option.  The clay drains poorly, but as I will have full control over how much water goes inside, I'm not sure if this is a real concern or not.   
  • Mix in a large amount of mulch or some other organic matter and roto-till it in?  The greenhouse is 18'x32' so it would take ~10cu yds to fill 6in deep. 
  • Mix in a large amount of perlite or sand to improve drainage?  But it would still be clay underneath so unless I shaped it to drain to the edges I don't see it making a difference other than perhaps improving root penetration.   Also I read that adding sand to clay is a bad idea unless you add a massive amount of sand. 
  • Just add mulch on top, and renew every year or two and let it works its way down over time. 
  • Create mounds or rows and plant trees there, perhaps with amended soil or 4x4 wood boxes to create "raised beds" that drain to the sides

Lauren08

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Re: clay soil amendments?
« Reply #1 on: September 10, 2017, 11:32:49 AM »
Hello
In a garden center near me in nc they have something called perma till. Im not sure of its price but i hear its a awesome soil ammendment. Its made of lava rock or sonething of the sort (i think) and it never degrades so you never have to replace it. I dont know of its what you have in mind but its a thought. You can also get bags of soil conditioner. Its like mulch

mrtexas

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Re: clay soil amendments?
« Reply #2 on: September 10, 2017, 11:36:54 AM »
As my greenhouse construction progresses I'm starting to think about soil.   I intend to plant trees directly into the ground inside my greenhouse.  My soil is clay but not too hard - the topsoil crumbles under hand pressure.  The dirt on my greenhouse floor is loose right now because it is recently excavated from the foundation trench.   I have an opportunity now to amend it, and/or shape it to affect drainage.   Any suggestions? 
  • Doing nothing at all may be a viable option.  The clay drains poorly, but as I will have full control over how much water goes inside, I'm not sure if this is a real concern or not.   
  • Mix in a large amount of mulch or some other organic matter and roto-till it in?  The greenhouse is 18'x32' so it would take ~10cu yds to fill 6in deep. 
  • Mix in a large amount of perlite or sand to improve drainage?  But it would still be clay underneath so unless I shaped it to drain to the edges I don't see it making a difference other than perhaps improving root penetration.   Also I read that adding sand to clay is a bad idea unless you add a massive amount of sand. 
  • Just add mulch on top, and renew every year or two and let it works its way down over time. 
  • Create mounds or rows and plant trees there, perhaps with amended soil or 4x4 wood boxes to create "raised beds" that drain to the sides
Don't amend clay soil. You will create a bathtub to drown your plants. Make a raised bed. Soil here is 100% clay, dig it up and fire into bricks.

Millet

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Re: clay soil amendments?
« Reply #3 on: September 10, 2017, 11:43:23 AM »
Raised beds is the best option.  Further, trees on trifoliate orange do good on clay soil and are also rated as good for wet soil.

Susanne42

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Re: clay soil amendments?
« Reply #4 on: September 10, 2017, 02:30:48 PM »
Michigan has a lot of clay, and areas with no clay seem to be silt, equally bad I think. There is a big green house near where I live and they have a huge grapefruit tree in there. i have not figured out yet if the container it is in, is bottomless or not but think for places with unfit soil it would be a good solution?







brian

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Re: clay soil amendments?
« Reply #5 on: September 10, 2017, 07:43:34 PM »
Mrtexas I totally agree with you on the bathtub effect - I definitely don't want free-draining depressions in the clay that will pool water.   However, I'm thinking if I graded the clay so it flows to the edges, then possibly put better soil on top for anywhere from a few inches to ~2ft, I should get the best of both worlds.  The "permatill" expanded-rock that Lauren mentioned looks similar to perlite... would help with drainage though I'd need a ton of it. 

Also, as Millet mentioned some trees will be fine with clay, however I'm not sure what the rootstock is on most of mine, and I also intend to grow some other tropicals - not sure how well they will handle clay. 

Here's a few of the ideas I have so far.  If I did a raised-bed-per-tree I could maybe use the existing 200ft of rootmaker material I have now and make 3-4ft diameter bottomless pots out of it. 




« Last Edit: September 10, 2017, 08:34:55 PM by brian »

Millet

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Re: clay soil amendments?
« Reply #6 on: September 10, 2017, 09:39:46 PM »
In my greenhouse I have a Dekopon and a Cara Cara growing in raised beds.  The Cara Cara has been planted in the bed a long time .  The tree is now 11 feet tall and 11 ft. wide, so I'm sure the roots have long ago grown into the hard pan soil under the raised bed.   For another citrus tree, I originally dug a hole 4-ft. wide X 4-ft. long X 4-ft. deep in the hard pan (took forever), and filled it with a good soil mixture.  It is also doing good.  The other 5 in ground trees I just planted directly into the ground, and they have grown to be large trees.  So there you have it, I did a lot of the original work, that perhaps I did not need to do.

brian

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Re: clay soil amendments?
« Reply #7 on: September 10, 2017, 09:57:22 PM »
Millet, that is encouraging.  Perhaps the easy way is the right way to go here.  That would be a nice change of pace for me. 

AnnonaMangoLord45

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Re: clay soil amendments?
« Reply #8 on: September 11, 2017, 12:14:34 AM »
Please don't use organic matter. Use sandy loam instead, pure sand, silt, and clay. Only dress compost on the top.

 

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