Soil formulas for bonsai in dry desert area

Brandon Gilbert

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Hello,
I live in tucson and was wandering if anyone would have any recommendations for a general soil mixture for being in the desert. I have a Japanese Maple and 'Amethyst Falls' Wisteria and a Juniper. I can oder pretty much anything I just need some tips for soil. Currently, I have been getting by with my peat, perlite, and crushed rock mixture but I want something I can really form roots with.
Thanks,
Brandon
 

Smoke

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Why can't you form roots with what your using? If you want more roots just use coarse sand and water appropriately. Soil mixtures are used for the benefit of the working man working and it's effects on water drainage or water holding. Throwing root making ability in there creates a whole new challenge. Coarse peat, perlite and coarse sand should work well.
 

AaronThomas

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Hey Brandon,
This is has been my mix more or less since I moved to Tucson...
50% organic potting soil made up of forest compost (pine bark and moss) Its a lot of organics but really helps with water retention during the summer. Deep pots help also...;)
40% decomposed granite (sifted with fine screen) ...will sometimes use 15% or 20% pumice
10% course sand (Quikrete pool filter sand... don't forget to wash)
Can get everything at Lowes and Mesquite Valley Growers on Speedway.
 

milehigh_7

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@AaronThomas how long have you been using that mix in the desert? That would be the death of anything here in Vegas. You are way better served to water more and retain less water. More oxygen = faster growth and less root rot.
 

Brandon Gilbert

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Awesome! I went to the Tucson Bonsai Society's show at the Botanical Gardens and I saw their soil was mainly small grain black lava rock and pumice. It made me wander about my soil. Beautiful trees there today, just saying.
 

fredman

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You will be surprised how long pumice holds on to its moisture. Put a handful of pumice in a stocking. Weigh it, dunk it in water and weigh it again. Weigh it every hour and see how long it takes to get back to its dry weight again. I was very pleasantly surprised. When it turns white and it looks seemingly dry, it still contains water.
This simple test can tell much about what you can expect from it in your area...;)
 

AaronThomas

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@milehigh_7 Been using pretty much that ratio since about 09' ... this year I actually increased the organics a bit. Honestly... using a soil mix that had more aggregate in it, I was watering 2 or 3 time a day during the summer. As it is I'm watering every day. Winter, fall and spring I just need to monitor and make sure I don't over water.
I should mention @Brandon Gilbert most of my trees are elms...
 
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AaronThomas

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@Brandon Gilbert ... I am still learning so I don't want to steer you in the wrong direction. Did you ask anybody at the Bonsai Society's what would be best for your trees? I have to check that out over there!
 

milehigh_7

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@Smoke is really close to you both in climate. I would heed his advice. Also Brandon don't be too sad if the Japanese Maple does not make it. You will have better luck with tridents.
 

AaronThomas

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Brandon- Acme sand and gravel Tucson
Awesome tip!!!
Went by there today to check it out. They have just about everything for dirt cheap (get it....). Got 1 bucket of pine mulch, 1 bucket of pumis and one DG for $10.
I figure that since I'm having trouble with one tree because of crap soil... The first sign of my other trees having issues I'll at least have the components on hand should I need to remedy the issue.
Here's a pic before sifting...
image.jpeg

Here's after sifting...

image.jpeg

Definitely should check it out @Brandon Gilbert
 
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