I wanted to share the results from the sawdust bed and how the California Junipers responded. I was pleasantly surprised, and happy with the results.
Information in order to replicate these results:
This was located in an unheated hoop house (16’x25′) in the Mojave Desert (Apple Valley). They were placed over two layers of weed barrier cloth directly on top of the ground. There was moderate to complete protection from wind in their location and most of the non summer months were in full to partial shade. These California junipers were either full bare roots or partial bare roots upon placement into the sawdust bed (In no way am I suggesting to now bare root yamadori and just use a sawdust bed). They were collected Nov 9th after a significant amount of rain, and kept in the sawdust bed for a year.
The hoop house reached temperature extremes up to 80°F and down to roughly 30°F. These extremes were between date of collection (Nov 9th iirc) and the date at which I opened the ends of the greenhouse and added 30% shade cloth over the top (April-ish). Temperatures in the summer were higher, up to a forecast of 105°F though temperatures inside the tunnel weren’t taken. Humidity was pretty literally at 100% the whole time, so that had to help significantly. If I had done this outside I don’t think the results would’ve been as great, but I might be wrong.
Once freezing temperatures had ceased (around mid April to early May) a misting system using spot spitters and drip irrigation tubing would go off anywhere between every 3 hours to once or twice a day depending on what season it was.
I used wood shavings from Tractor Supply, and I think these were the more coarse ones (flake): https://www.tractorsupply.com/tsc/product/tractor-supply-co-flake-premium-pine-shavings-covers-8-cu-ft-5027706
After all that here are the photos of the root systems and the final potted junipers:
Going from virtually 0 fine roots to this below is quite promising for the future.
Below is a close up of one of the junipers that sent out adventitious roots really high up on the trunk. It zooms out so you can see how high it ended up being.
Here was the root system of one of the trees after root reduction was done. I was slightly bothered that this particular juniper seemed to have almost all of the roots emerging from 3 locations, but I see that changing in the future.
And here are the results after taking them out of their location on the ground that is mulched atm from our recent 25°F night.