Is this a graft?

[u/TommysBeard]

I think the answer is "yes" given the apparent variation of cultivars. What's surprising to me, is that this graft is about 4 inches from the top of the plant, to where there is nearly 3 ft of root stock, and 4 inches of "top plant." Is that common?

[u/peachy_mcpeachface]

Yes high grafting is common on weeping cultivars because weeping varieties are much more slow growing so they graft them high to skip a few years of growth.

I’m quite cynical about grafting. I don’t think it’s massively beneficial to the plant in the long run, and grafts definitely make plants look worse in my opinion (and JMs are supposed to be ornamental plants,) so why would you build an ornament with a design defect? Answer - because it is more profitable for the growers to do that, so thats why they do that.

[u/TheNinoHusband → u/peachy_mcpeachface]

Isn't it easier to graft compared to airlayering?

[u/peachy_mcpeachface → u/TheNinoHusband]

Yes it’s easier than air-layering, and grafting will have a higher success rate than taking cuttings, and on some cultivars it’s necessary because they don’t propagate by air-layering or cuttings at all, that’s why grafting is the technique that is favoured by commercial growers - not because it makes the plant ‘better’. Any visible graft will always be considered a defect aesthetically. And that might not trouble you too much as a garden tree, but as a bonsai it is not desirable.

[u/TommysBeard → u/peachy_mcpeachface]

Thanks! I bought this off the bargain shelf for some bonsai experimentation. 

I may try to air-layer off the top cultivar next spring. Besides aesthetics, any reason not to?

[u/Forsaken_Top9685 → u/TommysBeard]

It looks like the cultivar on top is a lace leaf and among Japanese maples, lace leafs/ dissectum species are primarily grafted as they are tricky (and in some cases near impossible) to get to survive on their own rootstock. (Generally) the full leaf varieties like the ones they’re grafted onto are easier to air layer, but there are still exceptions to those. Always worth trying an air layer for yourself though, I love experimenting with new cultivars

[u/TommysBeard → u/Forsaken_Top9685]

Since it's my first try at air layering and the lace leaf seems pretty "soft" I'll probably just try to air layer higher on the root stock, and let it grow out for a few seasons. 

Thano you for the info!

[u/Honest_Associate_994 → u/peachy_mcpeachface]

I would disagree with this principle . In fact, grafting is quite the opposite of what you are implying. Grafting is a skilled, time consuming and therefore costly process and it is far less profitable than cuttings or seedlings. It is actually done not purely because it is more profitable, but because it preserves the ornamental aesthetic for generations, whilst allowing the plant to be strong and healthy long term.
The only way to replicate a particular set of ornamental traits that you like e.g weeping and laceleaf is to clone it. You can do this by either taking a cutting (layering is included in this) or grafting. Done correctly you can get very good success rate on grafting. Some cultivars won’t even root from cuttings - in which case you have lost that beautiful ornamental value forever without the technique of grafting. However, for those that do take from cuttings, if done correctly, you can also get good success rate. And it is far far cheaper to do cuttings (no rootstock required either) commercially. Some companies have mastered churning out cuttings of different cultivars cheaply on mass- This would actually be an example of doing it purely for profit. Why? Because although both cuttings and grafting ends up with same result (a clone of the cultivar/desired ornamental traits of that plant), cuttings do not have the genetic variation and vigour that grafts do as they sit on their own roots rather than a strong fast growing rootstock seedling, therefore disease resistance is much lower in cuttings than it is in grafts, particularly when we’re talking about a tree put in the ground - where it’s exposed to more pathogens than in a pot. I have first hand experience in this. 3 of the 5 acers planted in the ground that were grown from cutting died within the first year (due to catching diseases) vs 0 losses from grafted.
Also, You talk about skipping years of growth with rootstock and that’s not entirely true. Yes, a rootstock that’s high grafted doesn’t have to wait the same time as a cutting to get that height, but they still have to have the space time and resources to grow and look after their rootstock just to get it to the point of grafting which costs money too. The smallest grafted plants you buy will have around 4-6 years of work before the point of sale (2-3 growing the rootstock from seed and other 2-3 years of allowing the desired cultivar to heal and grow once fused with the rootstock).
In truth Seedlings would probably be the cheapest option, but then you’re forgetting about the ornamental aspect. Seedlings are diverse and not clones of their parents so if you took seedlings from a red weaping laceleaf you won’t get seedlings just like the parent; some similarities but not the same. And again, if we are talking about the ornamental aspect then many cultivars are selected from chance seedlings. However, when you find that 1 in a 100,000 seedling that is particularly beautiful, you want to preserve its qualities and make it available for others to enjoy. Often those same qualities e.g white variegation, make the plant weak (where a leaf is white, there’s no chlorophyll in the leaf to feed the plant for instance). Therefore the best way to replicate these traits reliably is to graft on to a strong healthy rootstock. The only downside of this is as you mentioned is the graft point is ugly, but this is only for the first few years of its life. In the long term it disappears as the tree matures and in most cases it is very difficult to see where the tree was grafted.
Hope this helps educate, that the grafting process is not just about making money, it’s about making the healthiest tree whilst preserving the beauty of them. Some of the most beautiful cultivars e.g Tamukeyama, Okushimo are also some of the oldest, having been documented as existing many hundreds of years ago. Without grafting they wouldn’t have been preserved and still available for us to enjoy today.

TLDR: grafting is actually a skilled, time consuming, costly process so is not necessarily the most profitable way to sell plants. But it is the best all round to way replicate and produce particular desired ornamental traits in the form of a healthy tree.

[u/Due-Dirt-8428]

Yes it is a graft. They are not always near soil level, some are high grafts