These 'Kanzan' trees don't look top grafted, but I can't tell if they've been grafted at ground level. They're a row of street trees, on one block and then around the corner, all about the same size, so surely either all grafted or all not. But some appear to fan out at the base as if the trunk has sent down the roots, as the one in the first row, and others seem to have an uneven join to the roots at ground level, like the one in the second row. Is it possible to tell if they're grafted? and around the corner While I'm at it, what about this 'Shirotae'? Same question.
I'll just keep asking until someone decides to explain this. Here's another group of 'Kanzan', at Sutcliffe Park near Granville Island. The surrounding greenery has been cut back to reveal the base of the trees, so a good time to ask whether these are ungrafted trees. They appear to be so to me. The second and third photos are the same tree. These are from one tree. I think these four were all from one tree.
Several shown are clearly grafted. Non-grafted trees don't have sudden changes in bark features or stem diameter corresponding to a horizontal line going around the stem. Otherwise, 'Kanzan' has been produced commercially from cuttings so specimens resulting from this might be encountered here.
To add to what Ron said, photo 7 in the first post looks like a classic example of a graft line, about halfway up the picture.
OK, thanks Ron and maf. On several of them, the bark looked the same on the trunk and the branches (particularly on the silver-coloured ones) and seemed to have places where it continued unbroken from the trunk up to the branches. So that would just be well-done grafting, which we don't see so much on our cherries.
Named cherries can also be reproduced from cuttings, but grafting is usually the preferred commercial method (much like the situation with Japanese maples). Another possibility is if any of the trees in question were grafted low, the graft point could have become buried in the ground if the soil level was raised or the tree was planted too deep.
These are different trees that demonstrate maf's point about the graft being underground. I saw this row of 'Kanzan' on Wall St between Eton and Powell, and seeing all the 'Kanzan' growth off the trunk and coming up from the ground even 10cm away from the trunk, I figured I could probably say these trees were on their own roots. But here, 20cm from the trunk was another shoot, and this had definitely avium leaves on it. So, grafted. P. avium leaf on the left, 'Kanzan' on the right.
I've got my answer for the trees in the original posting. I saw lots of new shoots coming out of the ground and they were all P. avium leaves. So grafted.
Re: Top vs bottom grafting On this two-block stretch of 'Kanzan' on 3rd at Fir, the trees on the south side are grafted at the ground, and the trunks are in excellent shape. Across the street, some of the trees appear to be grafted high, and the trunks show all kinds of signs of disease, just like so many around town. The lower set of leaves in the third photo are P. avium. All these trees appear to be similar in age, though I suppose there could be a few years' difference in some and they could be from a different grower. I mentioned previously how good the grafting seemed on many of these, as there was such a good fit between the rootstock and the scion. That doesn't seem to be the case here on this 'Snow Goose' planted two years ago in Stanley Park. Is this fine, or should this have been rejected?
Grafting 'Snow Goose' on mazzard cherry (Prunus avium) rootstock is probably a mistake, regardless of whether it is a high or low graft. In this case, you can see the differential growth rate of the rootstock to the scion. 'Snow Goose', like 'Umineko' (the two cultivars appear to be identical), is a shrubby plant, much less vigorous than P. avium. The swelling that occurs at the graft union eventually produces deep cracks, which the adult female cherry bark tortrix (a boring insect) finds ideal for oviposition. And any damage around the base (errant line-trimmers and mowers are the usual suspects) will stimulate suckers that will overtake the scion.
Douglas Justice told us that in Japan, the ornamental cherries are grafted, often below the planting line, and the rootstocks used are Japanese trees like 'Somei-yoshino' and something else - was it Prunus incisa? I noticed some shoots from near this 'Kanzan' at Nitobe Memorial Garden at UBC today. The third photo are leaves on the tree; fourth photo are the shoots from the ground near the tree. Do these look like incisa leaves? They're definitely not avium.
According to Kuitert (Japanese Flowering Cherries, Timber Press, 1999), seed-grown Oshima cherry, Prunus speciosa, is the most common rootstock in Japan. 'Mazakura', a Sato-zakura (Japanese village cherry), which is cutting-grown, is also used for "garden" cherries and P. x yedoensis (Yoshino cherry) cultivars. The smaller cherries, such as cultivars derived from P. x subhirtella (spring cherry), P. pendula (thread cherry) and P. incisa (Fuji cherry) are typically grafted on P. x subhirtella seedlings. "Finally" (he says), forms related to P. spontanea (Japanese hill cherry) are grafted on seedlings of that species. He goes on to say that grafting is a "temporary" measure. Grafts are made low on the rootstock and then once successfully growing, the rootstock is buried so that the scion (top part) makes its own roots. Clearly, traditional Japanese methods are superior to the Western "one-size-fits-all" propagation of every kind of ornamental cherry on P. avium (mazzard) rootstockâto say nothing of the imprudence of the standard Western nursery practice of top-grafting.
Thank you, Douglas. I'm sorry I totally misstated what you said. If the scion makes its own roots, then if we see shoots from the ground that do match the tree, even that does not demonstrate that the tree is not grafted. All we can notice is evidence of grafting, but we can't really demonstrate that a tree is totally on its own roots unless we have its planting history.
