TN_Jim
Omono
No doubt..will keep you posted.
Beech (Sylvatica) & Hornbeam (Betulus) Thread Grafting
- Thread starter Aiki_Joker
- Start date
Aiki_Joker
Shohin
Wow! The first season of growth is surprising on these grafts guys! All looks successful so far. Will get pics and updates once the trees are fully dormant (next month or so). Man, there are big differences between these two spp. I understand why people are loathed to graft beech now. Its not just that the probability of success is lower but there is significant difference in the reactionary wood with this particular beech and this particular graft. It wouldn't be invalid to assume that all Sylvatica will have some of this trait. A serious amount of thickening (potential for this to be uneven taper if on a potted tree, or advantageous if done correctly). This season it looks like approx. 2mm extra wood has been laid down on one side of the trunk below the graft. Its real muscle wood lookin' now! This is an awesome example of how the tree has rerouted transport channels around the graft injury. The hornbeam hasn't changed significantly as far as I know. Deeper analysis to come once I get pics!
Aiki_Joker
Shohin
European beech after one growing season, the graft has grown in well but with significant reactionary wood surrounding the scion branch at the new branch collar (figures 1 & 2).
Figure 1: EU beech scion entry wound after one growing season.
Figure 2: EU beech scion exit wound after one growing season.
Extensive thickening of the main trunk has occurred at the graft site (figure 3). The string used to secure the graft was removed early in the season when it was found slightly constricting the bark. By this time the attachment was deemed reasonably robust and no further securing devices were installed. Encircling marks on the bark can be seen approximately two inches below the graft point (figure 3).
Figure 3: Side view of the EU beech thread graft showing widening of the trunk parallel with the graft wound and encircling marks from bracing string removed mid summer.
European hornbeam after one growing season. Upon visual inspection, this hornbeam generated less reactionary wood across the girth of the graft stock and less cambium at the entry/exit wounds than the above Beech (Figure 4). Graft incorporation is deemed progressive.
Figure 4: European Hornbeam thread graft after one growing season.
Figure 5: European hornbeam thread graft entry. Both exit and entry graft unions show less reactionary cambium tissue and look more aesthetically pleasing than the beech.
Comparison of the hornbeam thread entry before and after. Some reactionary thickening has no doubt occurred. Stock bark shows surface signs of cell division primarily above the graft wound (Figure 6).
Figure 6: European hornbeam thread graft before (left) and after (right) one growing season.
Comparison of the European Beech. Before and after orientations are slightly different (Figure 7) and do not illustrate thickening sufficiently. These angles illustrate the vigor and cambium growth well. For reference, the thickest point in the beech graft stock after the season is pictured above (Figure 3).
Figure 7: EU Beech thread graft before (left) and after (right) one growing season.
Current Conclusions:
Visual inspection suggests that this procedure on this EU beech likely produced significantly more reactionary wood and cambium than the EU hornbeam. Both trees were of similar age, girth and location. The beech could be considered to be in full sun, while the hornbeam in full sun/partial shade. Both grafts show good stock to scion incorporation. However, scion branches will not be severed now. Remaining completely untouched, they will be evaluated next growing season. The aesthetics of this hornbeam graft can be considered better than the beech after one season. This may be a reason that the general consensus amongst our community is, threading beech is not a good plan. Furthermore, it is worth noting that based on the visual inspection, this beech has likely put significantly more resources into its healing process by generating more tissue volume than the hornbeam. If both trees were under additional stresses such as bonsai training activities, the increased resource draw exhibited by the beech could translate to a higher risk of graft failure in comparison to the hornbeam. Buds on both scions (and both sides of the stocks) all survived. The graft orifice on the beech was slightly larger than the hornbeam due to the bud size. This and the minor constriction from the securing string early in the season, could have contributed to the aesthetically jarring girth and cambium reaction of the beech during this first growing season.
Figure 1: EU beech scion entry wound after one growing season.
Figure 2: EU beech scion exit wound after one growing season.
Extensive thickening of the main trunk has occurred at the graft site (figure 3). The string used to secure the graft was removed early in the season when it was found slightly constricting the bark. By this time the attachment was deemed reasonably robust and no further securing devices were installed. Encircling marks on the bark can be seen approximately two inches below the graft point (figure 3).
Figure 3: Side view of the EU beech thread graft showing widening of the trunk parallel with the graft wound and encircling marks from bracing string removed mid summer.
European hornbeam after one growing season. Upon visual inspection, this hornbeam generated less reactionary wood across the girth of the graft stock and less cambium at the entry/exit wounds than the above Beech (Figure 4). Graft incorporation is deemed progressive.
Figure 4: European Hornbeam thread graft after one growing season.
Figure 5: European hornbeam thread graft entry. Both exit and entry graft unions show less reactionary cambium tissue and look more aesthetically pleasing than the beech.
Comparison of the hornbeam thread entry before and after. Some reactionary thickening has no doubt occurred. Stock bark shows surface signs of cell division primarily above the graft wound (Figure 6).
Figure 6: European hornbeam thread graft before (left) and after (right) one growing season.
Comparison of the European Beech. Before and after orientations are slightly different (Figure 7) and do not illustrate thickening sufficiently. These angles illustrate the vigor and cambium growth well. For reference, the thickest point in the beech graft stock after the season is pictured above (Figure 3).
Figure 7: EU Beech thread graft before (left) and after (right) one growing season.
Current Conclusions:
Visual inspection suggests that this procedure on this EU beech likely produced significantly more reactionary wood and cambium than the EU hornbeam. Both trees were of similar age, girth and location. The beech could be considered to be in full sun, while the hornbeam in full sun/partial shade. Both grafts show good stock to scion incorporation. However, scion branches will not be severed now. Remaining completely untouched, they will be evaluated next growing season. The aesthetics of this hornbeam graft can be considered better than the beech after one season. This may be a reason that the general consensus amongst our community is, threading beech is not a good plan. Furthermore, it is worth noting that based on the visual inspection, this beech has likely put significantly more resources into its healing process by generating more tissue volume than the hornbeam. If both trees were under additional stresses such as bonsai training activities, the increased resource draw exhibited by the beech could translate to a higher risk of graft failure in comparison to the hornbeam. Buds on both scions (and both sides of the stocks) all survived. The graft orifice on the beech was slightly larger than the hornbeam due to the bud size. This and the minor constriction from the securing string early in the season, could have contributed to the aesthetically jarring girth and cambium reaction of the beech during this first growing season.
TN_Jim
Omono
Interesting and thorough image, observation and detail. Goodness for sure!
Do you have any idea of any potential means of technique or approach to the beech to optimize this observation going forward -what if anything could possibly be applied to facilitate a more desirable healing and response in first season? ...or is this just the species..?
Too, I especially respect your ideas of partitioning of resources with regard to stress.
Thanks
Do you have any idea of any potential means of technique or approach to the beech to optimize this observation going forward -what if anything could possibly be applied to facilitate a more desirable healing and response in first season? ...or is this just the species..?
Too, I especially respect your ideas of partitioning of resources with regard to stress.
Thanks
0soyoung
Imperial Masterpiece
If you remove buds on the root side of the thread near the threaded stem (say, to 6 inches away) you will know that the phloem has been throttled on the exit (thread branch tip) side by the difference in the thicknesses of the thread on the entrance versus exit side. The entrance side will be poorly fed and won't thicken as much. Usually, but not necessarily a large difference will indicate that the graft has taken.
Growth of xylem/wood on the exit side is necessary for a complete graft - I am unsure how to know other than simply cutting off the thread at the entrance. The time honored procedure is to scrape the bark an cambium off a side of the thread near the entrance. In my experience this will either do nothing or it will cause the thread xylem to be jammed up (via normal damage response), so I just make an educated guess and cut when the thread thicknesses on the two sides are dramatically different. However, if one has attempted air layers on the species, one should be able to 'inform' their guess by the amount of thickening girdled/tourniqueted stems the species tends to exhibit.
River's Edge
Imperial Masterpiece
Wonderful thread detailing your approach. Have you used the same approach with a different sealant. I have had bad experience with fluid type sealant on grafts. One spring, i decided to try the new green fluid sealant that worked wonders for healing scars on maples. So i used it for several thread grafts and approach grafts with very mixed results. Lower success rate than normal. When i switched back to more traditional methods, cut paste, latex caulk, plumbers putty and grafting wax the results went back to normal success. My theory was that the fluid type seal actually crept between and interfered with the joining.This was based on a visible green sealant layer between the scion and host when the failed grafts were exposed. Just an observation from experience. I found this on what appeared to be a successful approach graft when separating after two growing seasons even though there was significant thickening on the exit side.
If there is a question, i would check for that possibility. I agree with those who note that thickening is not a sure fire indicator that a graft has taken.
Aiki_Joker
Shohin
Ha ha ha, thanks TN_Jim! Tried to be a thorough as possible so people could see what happened and make a decision whether to try this. Also, I learned quite a bit writing this. Doing it this way helps crystalise thought for me
The only thing I can think of is nibbling the cambium off once it has healed or waiting until the branch thickens and seeing if the bulge becomes insignificant. To mitigate the aesthetic damage first season, people do wrap raffia around areas that they do not want to bulge excessively. The guy Dan Barton in England recommended it when trunk chopping elms in a V configuration to develop broom style trees. His results were really good, with little to no bulges where new shoots broke. The issue I would envisage here would be trying to get the pressure even around the scion branch. Dan wrapped circularly perpendicular to the trunk. This provides even mechanical pressure on the area likely to bulge. With a thread, its not so easy to get the required pressure as wrapping would have to be at multiple angles, but not impossible I think.
Aiki_Joker
Shohin
Great plan 0soyoung, I will look into doing this for sure!
Aiki_Joker
Shohin
Thanks River's Edge! I have never used cut paste or wax, but I can see that this sealant definitely incorporates itself on past chops I have done. I does harden and dissolve away to a thin layer or flake off depending on ambient temp. In the middle east it flakes more often than not. It does not set as hard as epoxy resin though. I would imagine the cambium may crush and crack it, growing around and through it if incorporated. Similar to what happens with incorporated bark as branches fuse together.
One reason I have never tried cut paste is that I'm always aware of infections and airing wounds out. This sealant contains intermediates and carriers that are antifungal and antibacterial and takes a few days to set or a week depending on weather. After this the seal is water repellent but breathes over time by micro cracking. The drying time gives it time to seep into the cracks and crevices. The solvents eventually flash off but the concentration is toxic on the wound for days (at least). This exposes pathogens such as bacteria or fungi for more than enough time to seriously knockdown their populations. I guess I should not worry too much on this as trees have CODIT but can't harm to help them out. I had a beautiful larch I found in a skip die this summer showing signs of phytopthera ramorum (red oozing canka). Canadian poplar in the ground here fought hard too, not sure what it was but looked bacterial
0soyoung
Imperial Masterpiece
Any die back of the cambium on the exit side affects the same as having drilled a bigger hole and set the thread toward the bottom on the hole --> makes the graft take much longer. IOW it is worthwhile to cover the exit joint with the tread with some kind of putty or what not to prevent desiccation - it only needs to be in place for 10 to 15 days for a sealing epiderm to be generated by any exposed cambium.
If you are seriously concerned about a pathogen being introduced, an alternative to what you are doing would be to spray and wipe the entrance and exit areas of the trunk prior to drilling with my fave peroxide solution (2 tablespoons 3% in a quart of water) and spray the thread before inserting it. Wiping with isopropyl alcohol would likely suffice, but peroxide is a broad spectrum antiseptic, meaning it is anti-bacterial as well as an indiscriminate fungicide.
If you are seriously concerned about a pathogen being introduced, an alternative to what you are doing would be to spray and wipe the entrance and exit areas of the trunk prior to drilling with my fave peroxide solution (2 tablespoons 3% in a quart of water) and spray the thread before inserting it. Wiping with isopropyl alcohol would likely suffice, but peroxide is a broad spectrum antiseptic, meaning it is anti-bacterial as well as an indiscriminate fungicide.
Aiki_Joker
Shohin
Great advice 0soyoung! I use peroxide over IPA too. More concentrated though for treating bougainvillea chops when they have been outside in summer. I didn't know it was effective at such low concentrations! ?Nice?
Paulpash
Masterpiece
I've learnt that it's important to seal both sides of a thread graft with a putty type sealer. The success rate was much higher than none or a liquid sealer. If dessication occurs round the hole it will fail so ideally we'd like to see callus forming all round the exit point. Secondly, if anything seeps between the scion and exit hole (water, liquid sealant) it will similarly fail too. It's hard to say from the pictures if it has taken and I agree with your assessment to leave it alone next season for more definite proof of a more noticeable difference in girth between entry & exit points.
Just a final point too. The graft is being performed on a very vigorously growing, ground grown tree. To get sufficient thickening for a successful graft on a tree in a training pot would take far more time.
Very interesting thread, thanks for documenting it. Please update next season
Just a final point too. The graft is being performed on a very vigorously growing, ground grown tree. To get sufficient thickening for a successful graft on a tree in a training pot would take far more time.
Very interesting thread, thanks for documenting it. Please update next season
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Paulpash
Masterpiece
@Walter Pall Can I ask if you have ever thread grafted branches on a Beech or know of someone who has successfully done so? I ask because of this thread :
https://www.bonsainut.com/threads/b...ulus-thread-grafting.32694/page-2#post-608030
and because of your years of experience & travels. Your thoughts on this would be really interesting.
https://www.bonsainut.com/threads/b...ulus-thread-grafting.32694/page-2#post-608030
and because of your years of experience & travels. Your thoughts on this would be really interesting.
Walter Pall
Masterpiece
I have not done a threadgraft on a beech, because it was never necessary for me. I think it shold be quite easy. All one would have to know is whather a speicies can be airlayered easily. If that's the case then a threadgraft is a very good bet. This does not mean that a threadgraft should not be tried on speices which don't airlayer easily. it only has less chance in my opinion. Airlayers on beeches work very well.
Aiki_Joker
Shohin
I've learnt that it's important to seal both sides of a thread graft with a putty type sealer. The success rate was much higher than none or a liquid sealer. If dessication occurs round the hole it will fail so ideally we'd like to see callus forming all round the exit point. Secondly, if anything seeps between the scion and exit hole (water, liquid sealant) it will similarly fail too. It's hard to say from the pictures if it has taken and I agree with your assessment to leave it alone next season for more definite proof of a more noticeable difference in girth between entry & exit points.
Just a final point too. The graft is being performed on a very vigorously growing, ground grown tree. To get sufficient thickening for a successful graft on a tree in a training pot would take far more time.
Very interesting thread, thanks for documenting it. Please update next season
Will definitely continue to update this Paulpash. Appreciated.
TN_Jim
Omono
I've learnt that it's important to seal both sides of a thread graft with a putty type sealer. The success rate was much higher than none or a liquid sealer. If dessication occurs round the hole it will fail so ideally we'd like to see callus forming all round the exit point. Secondly, if anything seeps between the scion and exit hole (water, liquid sealant) it will similarly fail too. It's hard to say from the pictures if it has taken and I agree with your assessment to leave it alone next season for more definite proof of a more noticeable difference in girth between entry & exit points.
Just a final point too. The graft is being performed on a very vigorously growing, ground grown tree. To get sufficient thickening for a successful graft on a tree in a training pot would take far more time.
Very interesting thread, thanks for documenting it. Please update next season
What kind of putty would you apply to the tree (beech) in this case?
Also, when applying putty, are you careful to not let ANY of the material go into the bored hole where contact (in the gap, where cambiums are not touching/first-binding) is also not at first?...only seal it off?...is this what I’m understanding?
Paulpash
Masterpiece
I use bonsai putty that you get in a tub or the duct seal that many on here use. Both of these do a good job of excluding water from the holes & promote callusing. I try as best as I can to not get any of putty between the hole and the branch I've poked through. You can also use the wedge technique that basically pushes the donor branch snug against the bottom of the hole. Push the branch through the hole you've drilled, cut a small wedge such as a barbecue skewer and insert it at the top of the hole. Cut it flush with a branch cutter then seal. You can optionally wound the underside of the scion (pushed through branch) where it intersects with the hole by gently pulling on it and scraping the underside to reveal the cambium. When you release the scraped part it should sit above the hole. Then wedge & seal. This ensures good contact with one side of the hole & excludes water from entering as there slight downward pressure from the wedge. This technique is not needed for thin barked trees like maples but useful when your hole is bigger than you'd prefer due to bud size (Beech probably has the biggest dormant buds of any deciduous?) or swell if you have timed it a little late.
0soyoung
Imperial Masterpiece
I too 'wedge' the thread with a bamboo skewer. However, I don't wound the thread and I think wedging the thread up, tightly against the top of the hole is better than down.
I don't intentionally wound the thread because it is highly likely to choke off the thread's xylem causing the exit side thread to desiccate and die.
Gary Wood convinced me to wedge up several years ago. My reasoning is that the cambium of the trunk grows more strongly on the top and may even die back on the underside of the hole. This is because carbohydrates flow down the tree in the phloem (inner bark) much like a fluid film. When it encounters an object, such as a hole, there tends to be an accumulation on upstream side and a pointed 'shadow' on the down-stream. BTW, the famous technique (possibly due to Ebihara) of partially sawing through a large branch, keeping the underside connected for several years before completely severing the branch is addressing this fact to promote faster healing.
I don't intentionally wound the thread because it is highly likely to choke off the thread's xylem causing the exit side thread to desiccate and die.
Gary Wood convinced me to wedge up several years ago. My reasoning is that the cambium of the trunk grows more strongly on the top and may even die back on the underside of the hole. This is because carbohydrates flow down the tree in the phloem (inner bark) much like a fluid film. When it encounters an object, such as a hole, there tends to be an accumulation on upstream side and a pointed 'shadow' on the down-stream. BTW, the famous technique (possibly due to Ebihara) of partially sawing through a large branch, keeping the underside connected for several years before completely severing the branch is addressing this fact to promote faster healing.
I am a bit of a latecomer here, but really enjoyed the thread and all the detail. I have the beech pictured here that I just received from Bill V. It is 23" tall and has a 1+" trunk with a great nebari as you can see. It has been suggested by several, that eventually, one or both of the forks at the top need to be removed. When that happens, I will have several nice top branches that could be grafted lower down to fill in gaps. I have never grafted before so I would practice before I would try it on the Beech. Several questions: on a thread graft why is it necessary to drill a hole clear thru the trunk? Why can't one just go 1/2 or 3/4 thru, pick a suitable scion, and cut it off so you have an inter-node with no buds to deal with for an inch or so, drill the hole just a tad bigger than that, and insert scion that still has 2-4 buds on it, wedge up with tooth picks if necessary, seal and wait. I guess I don't understand why it has to go clear through the trunk. I don't want a branch on both sides, opposite of each other, just on the bare side. Thanks for help, Peter
