Sierra juniper yamadori questions: pumice size, hormone/fertilizer, etc

[MeredithSK]

I am collecting Sierra Juniper at 8k+ feet (and coming back to Oakland, Bay Area) and have some questions I've been unable to find specific answers for despite looking in Nick Lenz's book, forums on this site, youtube, etc.
Lenz's book speaks on the differences between ground, field, and rocky mountain juniper- but doesn't have Sierra Juniper. Since there are such large differences between the treatment of other junipers, I only imagine the same could be for SJ.

Most sources all say pumice (or other non-organic) only, but vary on sizes or don't say at all. Can this be yakadama? Opinions vary wildly about removing or leaving native soil- some say leave some as there's a mycorrhizal relationship, others say remove completely. Again, this seems to vary on juniper species- but I haven't seen one specifically for Sierra Juniper).

Same thing with rooting hormone, fertilizer, or superthrive- Lenz says yes to superthrive on some species of juniper, but doesn't have SJ in the book.

For watering, some videos/places show leaving the tree in water bath for 24 hours after collection, then only misting for some unspecified. Some places say treat like a cactus (I can't see this in Oakland- we can have 80+ degree days well into October).

 

[MeredithSK]

Also: what are the differences between the care of california and sierra juniper?

 

[Potawatomi13]

Do you have access to Bonsai Mirai live streams/library? Most excellent info there in extensive library archive. If cannot afford membership believe can get free trial period to study videos. Much better info than can be found here! Also "might" find help in youtube video search. Best of fortune with invisible tree.

 

[PaulH]

I use medium size pumice, +- 1/4". No akadama or organics. I usually bare root but if a little native soil is left until later repotting its no problem. Misting is critical for aftercare. I keep mine in a cold greenhouse with misters on a timer 4+ times a day until new growth starts. I collect Sierra, California, and Utah junipers and treat all the same.

 

[yenling83]

Here's some tips for you, from my experience. I've been collecting since 2008, mostly Sierra Junipers. However, there's more than one way to skin a cat. PaulH has collected some really nice Sierra's as well! I've also heard of Californians using a technique where they build an individual green house around each tree for trees with less roots. Have fun and Good luck!

• Use straight/100% pumice-sift out the fines
• Put the trees in a tight wooden box or container that fits the root ball well with good drainage on the bottom
• Generally speaking-more roots=better chance of survival (There's a point where you just don't need anymore roots as well.)
• I never bare root conifers, I leave majority of the native soil on the root ball
• Put the box/container directly on the ground until it's growing strongly
• Make sure the tree is tied in and does not wiggle. This is under rated-giggling in the container will cause the roots to stall or not grow
• Fertilize the juniper (I'll usually start fertilizing a week after potting up for the first time)
• If the tree has lots of roots i'd place it in full sun(in the bay area) and I would not mist
• If temp jumps up rapidly, place under shade cloth
• I never mist any trees, but It could be beneficial for weak trees or trees with limited roots
• I find that misting trees tends to keep them alive, but makes them take longer to throw runners/new growth
• Balance of water and oxygen
• Saturate the root ball with water on the first watering-you can dunk the tree in water, you don't need to leave it there hours
• No one really knows if Super Thrive has any benefit, but it also likely can't hurt(I don't use it)
• Mycorrhizal relationship are important, but I don't think you can add mycelium back in to help these relationships
• Find whatever you can from Randy Knight-he's legit as they come for N American collecting.

 

[actionflies]

I recommend watching Tom Vuong video on YouTube with a lot of insights on collecting junipers. The 1 piece of info I got from watching Tom and Mauro videos is not to over water collected trees.