JWP Graft Union Dislocation

In one of Ryan Neil’s demo videos, there is a brief discussion of Japanese White Pine graft problems. Ryan states that Zuishio and Ko Ko Noe grafted onto JBP under stock inevitably fail after several years. Neil mentions that Shikoku and Miyajima JWP take to grafting well and rarely if ever break.

I had a little trouble hearing the audio and following the discussion. I’m wondering if just regular general species scions also eventually fail on JBP under stock.

The reason I ask is that I’ve recently started trying to graft JWP scions onto JBP rootstock as shown on Brent Walston’s grafting video. I'm not doing cultivars - just regular garden variety JWP grown from seed. If even my successful grafts will eventually fail, there’s not much point in continuing.

The discussion starts at about the 11 min mark in this video:
https://www.youtube.com/watch?v=UY2u-sBAUvc

Casey

I have yet to see a P. parviflora in a landscape nursery that isn't on JBP roots.

You might check out Bjorvala's Bonsai Art of Japan video series on YouTube - an early episode discusses old JWP bonsai that is grafted to JBP roots.

Happy grafting.

I had a brevifolia JWP that separated at the graft, about 80% of the graft failed to unite to the black pine stock. It didn't become obvious until a few years after purchasing it. I used the brevifolia as stock for more grafting onto black pine seedlings before it eventually broke off. Apparently it happens, it might be a grafting technique problem, failure of the scion to fully unite with stock. I've heard of the problem before from different Japanese sources over the years.

Paul

Thanks for the input, guys. Sadly, I won’t get to see this problem as all three of my grafts recently bit the dust. I took them in late March and thought that they were out of the woods. A heat spell hit and they went down hill quickly. I don’t know if I performed my grafts poorly or the heat cooked them.

Casey

Sorry to hear your grafts failed.

If you have seedlings, why graft? After all, white pine live on their own roots in the wild without problem. I can understand that cultivars may be weak, and grafting is the easiest way to propagate. There is nothing really to say that the species needs to be grafted.

Paul

the problem seems to be with 'dwarf' white pine varieties - i've even seen a mature semi specimen tree about 6" thick at the base snap off while been removed from the pot at repotting time. Then we could look closely at the inside off the trunk and it was easy to see a strong sap path only an inch wide maintaining the entire tree and the rest of the circumference and all the heart wood was barely knit together - very strange but maybe down to compatability or even differing growth speeds.

When you ask will normall white on black fail in a similar way i'd say no - the japanese started grafting these in 1928 and stepped up the process after the 2nd world war to make 1000's of export bonsai material trees. I have never heard of, or seen, one of the standard trees separate and I've put some of these trunks under very high pressure with metal bars, guy wires and torniquets over the years. i admit that it has been trees well over 25 years that we tend to bend or compress like this so a newer graft union may be weaker.

as to why graft............yes white pines live in nature on their own roots....but that means absolutely nothing in bonsai culture as rootstocks need to be strong, grow in a compact fine manner and critically they need to respond to root pruning. (Every species lives in nature ok, but many dont produce roots compatable with pot life). If the roots do not tick all these boxes you make life hard from day one, and this is backed up totally by how much weaker and temperamental white pines on their own roots are. Elevation plays a major part too - white pines are true mountain trees and need proper exposure & cold weather - black pines are lowland trees and like milder stable weather - we tend to keep our bonsai collections stable and protected and this is further reason why the black pine element does so well.