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Author Topic: I need to mix my own soil for cacti--in Bulk!  (Read 1762 times)

starling1

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I need to mix my own soil for cacti--in Bulk!
« on: April 30, 2015, 06:23:41 PM »


So I've started building a really big raised bed for my  fruit cacti. They're all various cereus types and opuntia. Tired of seeing them sitting all in pots getting bound.

It's 20 Feet long, 1/12 m wide, 1/2 m deep. Making it from cinderblocks which I'll stucco or something so it doesn't look completely hideous.

I need to to fill it with a good mix, but it needs to be realistically priced. Any thoughts?

nullzero

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Re: I need to mix my own soil for cacti--in Bulk!
« Reply #1 on: April 30, 2015, 07:19:20 PM »
Starling,

I remember you posted about making biochar. I would recommend using biochar mixed with lava rock or something. I found a reference from some Aussie cacti growers recommending it;

"We use it it seems to help for the rot prone ones if you can get it cheap enough it can't hurt. Alot of the QLD cacti society people use a mix based around this and volcanic rock."

http://www.shaman-australis.com/forum/index.php?showtopic=36202
Grow mainly fruits, vegetables, and herbs.

starling1

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Re: I need to mix my own soil for cacti--in Bulk!
« Reply #2 on: April 30, 2015, 07:23:16 PM »
Starling,

I remember you posted about making biochar. I would recommend using biochar mixed with lava rock or something. I found a reference from some Aussie cacti growers recommending it;

"We use it it seems to help for the rot prone ones if you can get it cheap enough it can't hurt. Alot of the QLD cacti society people use a mix based around this and volcanic rock."

http://www.shaman-australis.com/forum/index.php?showtopic=36202


Nullz, after the amount I had to make for the dragonfruit grove, testicular cancer sounds better than making more biochar. I just don't have it in me man lol.

I wish I could get pumice somewhere in bulk....this would make life a lot easier. I mean I could slowly make a good mix with coir, pearlite, sand, gravel and potting mix but this would get pretty expensive.

BMc

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Re: I need to mix my own soil for cacti--in Bulk!
« Reply #3 on: April 30, 2015, 07:45:47 PM »
You could get raw pumice by the truckload from the beaches around Caloundra. But you'd need to chuck them into a cement mixer for a few weeks to get the salt out.
You must be in tough ground to need to go to those lengths to grow cereus and optunia.

starling1

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Re: I need to mix my own soil for cacti--in Bulk!
« Reply #4 on: April 30, 2015, 07:52:25 PM »
You could get raw pumice by the truckload from the beaches around Caloundra. But you'd need to chuck them into a cement mixer for a few weeks to get the salt out.
You must be in tough ground to need to go to those lengths to grow cereus and optunia.

Well, the problem is it's clay--which might not sound that bad for cacti, but in reality is actually is. The opuntia can kind of take it, but everything else rots from the ground up. It turns into mud because there's no sand in it all. Very gluggy, very sticky doesn't take water well, but when it does get wet, it stays wet--so pretty much not good for anything. I really picked a bummer in the lottery of soil types.

nullzero

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Re: I need to mix my own soil for cacti--in Bulk!
« Reply #5 on: April 30, 2015, 08:02:53 PM »
Have you tried amending the soil heavily with gypsum?
Grow mainly fruits, vegetables, and herbs.

starling1

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Re: I need to mix my own soil for cacti--in Bulk!
« Reply #6 on: April 30, 2015, 08:58:05 PM »
Have you tried amending the soil heavily with gypsum?

Yep. I actually did a test to see if that would work by digging down into the hard clay, and pouring in a whole bag to let it dissolve. It did improve it a little bit--made it slightly more porous--but not a gamechanging amount. And that was literally a whole bag of it.

The only thing that seems to work is mulching and folding this into the soil as it breaks down. I use pure uncomposted horse manure and cheap forest mulch. I pile it deep. I have dung beetles at my place, and they really do work to funnel down into the harder soil, and the worms do the rest. But this process takes time--about three years to get a layer of good soil about 1/1/2 feet deep.

Anyway, I just spoke to a guy who supplies pumice and pearlite here, and he basically said that pearlite trumps anything and that I'm betetr off just buying a coarse grade of this in bulk. Surprisingly, it is much cheaper than pumice in bulk.

He also told me--and this is interesting--that in coir mixes, you shouldn't use anything but pearlite. Something to do with the way plants struggle to get water from the coir. He totally nixed my biochar setup, so I may have just wasted a lot of energy and time with that experiment  :(

 

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