Best root graft scions for Shimpaku?

So heres a pretty open ended question. I have an Itoigawa Shinpaku I'm going to split by root grafting one section(with Itoigawa foliage grafted just a bit below the root graft for vein maintenance), and wanted some input as to Chinensis cultivars with the fastest growing and strongest roots. I know bonsai pros in Japan keep numerous varieties of juniper around for various purposes not related to good foliage, such as quick root growth, quick thickening, Ect...just trying to find the best equivalents stateside.
Ryan
http://japanesebonsaipots.net/

Hi Ryan,
I don't know the answer but hope someone does; I'd like to know too.
Todd

unfortunately i can't give US specifics but usually the best roots are the local native varieties - and most often they have foliage we dont like as bonsai.

powerfull fast growing garden varieties that have long extension growth usually signify strong root growth too, but these are just general observations rather than a helpfull definite answer, sorry

regards Marcus

Just my opinion: I know of no other Juniper that has more vigorous roots than the Shimpaku. It is like in the beginning God decided to make the perfect tree for bonsai growers and that tree was and is the Shimpaku Juniper. You seldom if ever see any other species grafted into or onto a Shimpaku, the contrary is true, you see Shimpaku grafted onto the roots and stocks of a multitude of Junipers. Again; just my opinion, it sounds like you are trying to re-invent the wheel. The Shimpaku grows very well on its own roots, and if I needed to add roots it would be Shimpaku to Shimpaku. It is not an issue of the Shimpaku being a fragile tree, fussy and unmanageable, it is a wonderful tree and takes a boat load of abuse and comes back. It's like a liver transplant: The closer to the source the better the results.

Hi,

I think shimpaku is not an exact species of juniper though, (though it seems to have become named as a variety in the usa for selling as bonsai, so there may be a regional name variation ) -I believe in Japan it is actually a broad spectrum name for the chinese juniper Sp. and includes several varieties, some of which have terrible foliage for bonsai. Several of the wild collected shimpaku bonsai have long, thin droopy hanging foliage, some have sparse foliage spread along extended branches etc and if the trunk is good they end up with another shimpaku variety grafted to them. You can not totally rely on a name either - the foliage on similar trees in the same area will vary massively - the low valley trees evolve a different foliage to the trees higher up, so each tree needs to be evaluated on appearance - but as vance says the roots are notoriously good

These are a few of the named varieties of shinpaku junipers, although there are plenty more

Sargentii is an old named variety that has a nice deep green, reasonably tight foliage but goes have a tendancy to flower a lot - this is a bad trait for a juniper bonsai as it badly effects the refinement of the pads as every terminal ending in a flower will not grow ever again. If you find 70-100 year old import trees that have nice foliage they are likely to be sergentii

kishu is another variety - forms tighter growth and less flowering, good green colour too - this is probably the commonest variety used for young modern med / large field grown commercial bonsai

itoigawa is the well known variety of recent years, but originally a rare and highly prized tree from a very small region of Japan, a true yamadori itoigawa is a very rare tree, but thanks to propogation and grafting now they are common as bonsai material - very fine growth, much smaller size to the foliage than the others but not an easy variety as any poor care, over heavy styling or hard repotting sends the tree into a needle foliage stage that can last years - when settled conditions return the tree reverts to tight scale foliage again but you often have long bare branches where the juvenile needles grew then fell off.

there are loads of other varieties that can fall under the shimpaku umbrella too but the best roots to graft will always be from trees that do best in your exact location and climate. Over time the miss naming will cause great confusion and disscusion ! i learnt shinpaku (shimpaku), goyomatsu, kuromatsu etc are just broad terms that have named varieties within them, none are an actual variety in their own right.

whatever name tho they are great trees