Concave Cutters

[Newish in Oregon]

I just watched a new Winter Pruning video from Blue Sky Bonsai. Seemed like he was taking off branches with concave cutters but then 'cleaning up' the wound to make it flat/level instead of concave. Is that typical practice?

 

[pandacular]

Yes, this is very typical. The tool I most commonly seen for that cleanup is called a knob or spherical cutter.

 

[Bonsai Nut]

I just watched a new Winter Pruning video from Blue Sky Bonsai. Seemed like he was taking off branches with concave cutters but then 'cleaning up' the wound to make it flat/level instead of concave. Is that typical practice?

It depends on the wound. In many cases you want it to be concave, so when bark rolls over the wound it heals flat. However there are occasions when you actually want a raised surface versus a flat one. I'd have to see the video in question.

[EDIT] I watched the video and I thought it was strictly ok. It was beginner level and though none of the information was wrong, a lot of it was incomplete. I'll be honest - I did not see the section where he used a concave cutter. His trees were all quite small and I probably would have used scissors for all of my work. [/EDIT]

 

[Newish in Oregon]

@pandacular Thanks. Tho Bonsai Nut touches on it, I'd be interested in hearing why a concave cutter is used if one follows up w/ clean up.

@Bonsai Nut Thanks for your comments. I'm wondering tho if you found the right video. Here's the link

 

[TrevorLarsen]

To me it seems like it’s just the tool he likes best, since he cleans up the concave cut. You can do what he did a thousand ways he just like it this way.

 

[bluesky]

Hello! Just seen this thread, it's been a while since I posted on bnut.

The tool I used is a Ryuga curved concave branch cutter, it doubles as a wood hollower to some extent. For a major branch chop or trunk chop, the first year I leave a pruning stub to compartmentalize the wound and avoid dieback problems. Then the year after I remove the stub, and cut into the heart wood by a few millimeters (maybe 1/6" ?) , to let the callusing grow across the wound, as @Bonsai Nut said, rather than bulging outwards.

In the shorter version of the video I also used a dremel on the crab apple to carve deeper and more accurately.

For the record, @Newish in Oregon the video you posted above was the half hour long version, but probably version most people saw was the shorter 9 minute version called 5 Pruning Secrets... Wish I knew this 20 years ago.

 

[leatherback]

Hello! Just seen this thread, it's been a while since I posted on bnut.

The tool I used is a Ryuga curved concave branch cutter, it doubles as a wood hollower to some extent. For a major branch chop or trunk chop, the first year I leave a pruning stub to compartmentalize the wound and avoid dieback problems. Then the year after I remove the stub, and cut into the heart wood by a few millimeters (maybe 1/6" ?) , to let the callusing grow across the wound, as @Bonsai Nut said, rather than bulging outwards.

In the shorter version of the video I also used a dremel on the crab apple to carve deeper and more accurately.

For the record, @Newish in Oregon the video you posted above was the half hour long version, but probably version most people saw was the shorter 9 minute version called 5 Pruning Secrets... Wish I knew this 20 years ago.

Hey Fellow-tuber, never realized you were here too!
Grts, jelle.

 

[bluesky]

Hey Fellow-tuber, never realized you were here too!
Grts, jelle.

Hi Jelle, yep I should check in more often, love the bnut forums but y'know life gets in the way..

New month's resolution: look at bnut every day