Hopefully I can fill in the missing parts.
"Grow Stones" is a product used in the hydroponic industry for growing marijuana plain and simple. It is a recycled manmade product from glass to simulate pumice.
The two trees, a california juniper with bad roots and a trident maple consisting of five one inche trunked maples thru holes in a plate. Both were grown in 100% grow stones. The trident had a covering of sphagnum moss and the juniper had a covering of bonsai soil just to keep the light pumice like product from being washed from the pot during watering.
There is no "mix" and my use of the word should have been pumice instead of the word mix. For me it is just a catch all word for soil. Don't make this harder than it is. This was simply an experiment for those that were having such a cow over 1. grow stones, 2. growing plants in mediums period.
There is no magic medium for growing plants as the medium is not conducive to the plants growth. what the soil does is a couple of things;
It provides a moisture reserve for the roots.
It provides anchorage for the plant
It provides a place for fertilizer to breakdown.
It provides and attractive environment for the display of the tree.
If one can provide water without the need for soil, the plant would live.
If one can provide a stable holding apparatice so the plant can't fall over, the plant will live.
If one can provide nutrients for the plant, the plant will live.
Could we provide that for a plant without soil? Of course, we call it hydroponic farming.
The plants are anchored.
They are allowed to have roots in free air with water trickle.
The water is charged with a fertilizer solution.
Cool no soil. Some plants are grown in a medium to provide a place for the roots to anchor. This can be rockwool, hydrotone, pumice, Grow Stones etc, etc.
Now the problem, we use substrates from all parts of the country. Some have lava, some have akadama, some have haydite, some have turface and some have pumice. It seems that except soil makings from California, few people around the country have all of the aggregates to choose from without costly shipping and costly product, which adds up to double costly. No one wants to pay 60.00 for a bag of akadama shipped across the states. I don't blame them.
I brought up Grow Stones on my blog in Feb. 2013. I called it the Holy Grail. It was posted on Reddit and went viral and has been my largest month so far on my blog. That month saw 5026 views on my blog.
During the soil wars here then, and frankly every bonsai discussion forum since the internet, very few talk about air exchange. This is my holy grail. I feel that as long as the components are of the appropriate size, the medium doesn't really make that much difference. The problem with these soils made from pumice and lava only is that due to the size and the open pourosity of the medium, it dries too quickly. The addition of akadama helps me achieve that. It holds the water for a long time yet gives it up rather slowly. No other medium does that.
Many use turface because it is clay. It does not hold water like akadama nor stay wet for most of the day. It dries too fast. Why turface seems to work for people is the fact that the particle size is smaller and the capillary action keeps the soil more wet, which isn't always good either. Think of it more like the addition of sand. Need more wet soil, add sand.
Below Darlene is the bag and a close up of the product. Two particles will fit confortably on a dime.
