Confusion with JM trunk chop timing

[leatherback]

what's the big deal?

imho there is no great big deal.

Plants are not like animals, where blood is a crucial, yet very limited resource.
The liquid lost in plants is mostly water with some sugar and nutrients in there. Healthy plants have lots of supply and will seal the wound after one or several weeks.

 

[Shibui]

I have certainly experienced healthy maples bleeding excessively, sometimes for weeks and occasionally failing to leaf out afterwards. Not sure if that is climate related as many experienced cooler climate growers don't seem to have this problem. I've tried both wound sealants and neither stop this bleeding. The 'toothpaste' dissolves in the liquid and the plasticine type just lifts off the cut surface.
Also found, as stated by @River's Edge that root pruning stops bleeding immediately.

With that in mind I have trunk chopped Japanese maples from leaf fall though to mid winter (mild winter climate) with no problem. Also from mid winter though to leaf out in conjunction with root pruning also with no problem (and by the way, no reduction in spring growth as a result of pruning both roots and trunk). Also after leaves harden off through to summer with no problem.

However, bleeding is not the only problem associated with chopping JM. Problems seem to be associated with the extent of the chop. A large chop leaving one or no branches will often cause one side of the trunk to die off. Occasionally one or more roots will die off after a large trunk chop. Neither outcome seems to be associated with time of year.
Those affects are much less common with younger trunks under 1" thick.

I also note @River's Edge questioning why such haste to pre-emptively get rid of grafts. Agree that occasional grafts grow badly and look terrible but far more merge seamlessly as the trunks thicken. The problem seems to be that these are never seen or counted so the few bad grafts give all grafts a bad name. In the few cases where the graft swells or shows a change of colour or bark texture there are a few techniques that can keep the scion on understock while minimising any bad effects and still retain the advantages of the named variety and root stock. Too many less informed newbies taking too much notice of a few loud but less experienced others claiming all grafts are bad.

 

[roberthu]

I have not worked with any maples since about 2005. From 1992 thru 2005 had a nice Acer palmatum 'Arakawa'

Anyway - in my experience in my cold climate which is similar to the climate of the OP @The Warm Canuck trunk chopping in the middle of July is the best option. Ryan Neil spews a lot of "sciencey stuff" that often does not make sense to me. His techniques seem best suited to people in very mild. Pacific Northwest climates or for those who grow in greenhouses. If you have "real winters" and blindly follow Ryan's advice, you will loose trees.

Chopping in early or middle July in zone 5b or colder allows enough time for new growth to develop and harden off before winter. Hard pruning much later than July risks freeze damage. Autumn pruning can stimulate the tree to attempt to grow or for buds to loose a little of their winter dormancy conditioning.

I also like July pruning because the new growth is more compact. If I prune in spring, the new internodes will be very long and potentially out of proportion, especially in trees I am trying to transition from "nursery stock in training" to refined bonsai. Trees in this transitional phase of training tend to be vigorous, so for them summer pruning is best.

Now remember, I am a zone 5b maple grower talking to a zone 5 maple grower. Those of you growing Japanese maples in California and Georgia and Florida, ignore my timing. Your climate and your timing for pruning should be different.

The point you made about Ryan is very spot on. He did stress that fall pruning requires a lot more winter protection even for his climate. If someone can’t provide that, late spring pruning is going to be the best option.

 

[The Warm Canuck]

This worked! He's sending it soon.

 

[starleaf]

I actually just bought Adams's book and am waiting for it in the mail. The only place I seem to be able to buy Meriggiolis book, is Bonsai.co.uk, which will be $250 cdn incl shipping and taxes, so I'm going to hold off on this one, yes, maybe for Christmas.

Thank you for the clarification, on trunk chopping, that makes it way more clear to me.

I have some grafted cultivars (crimson queen), that I want to chop down to their Palmatum root stocks, (I tried Air Layering them, got a few roots but heard they don't do well on their own roots especially in my climate, so I abandoned the layer). It made sense to me, to chop them in the spring, to take advantage of the massive amount of energy, as these are still in large grow bags, with large root masses, and not a small Bonsai pots, it seemed to me that any loss of energy, wasn't a big deal.

Where did you find Peter Adam’s book? I haven’t been able to find any sources that still have it in stock. I am in BC Canada.

 

[The Warm Canuck]

Where did you find Peter Adam’s book? I haven’t been able to find any sources that still have it in stock. I am in BC Canada.

I honestly don't remember, I think I ordered it from somewhere in the states. However, before buying that book I would just buy Andrea Meriggioli's "Bonsai Maples". You can look him up on Facebook and message him, he'll personally ship you a copy. Honestly, there's not much additional information that isn't covered in Andrea's book.

 

[starleaf]

I honestly don't remember, I think I ordered it from somewhere in the states. However, before buying that book I would just buy Andrea Meriggioli's "Bonsai Maples". You can look him up on Facebook and message him, he'll personally ship you a copy. Honestly, there's not much additional information that isn't covered in Andrea's book.

Thank you, How much did it cost to ship Andrea Meriggioli’s book to Canada?

 

[The Warm Canuck]

Thank you, How much did it cost to ship Andrea Meriggioli’s book to Canada?

I can't exactly remember, it was pricey, all in, maybe around $200. It's worth it though.