What do you use to cut the bottom of an air layer?

[Bonsai Tree]

Hello. This past season I air layered a wild crab apple and in the spring I will be repotting it and getting all of the sphagnum moss off of the roots. I'm going to cut the wood back so all of the roots are on the same plane. I was wondering what tools you use to do this. I have a concave set of pruners and also a knob cutter, but I would prefer to get a smooth flat cut on the bottom. I'm not sure if this is necessary, but I was considering purchasing a trunk splitter tool because it's flat as opposed to the concave cut of the knob cutters. Is this necessary? I also have a small saw I can use.

 

[Cajunrider]

Hello. This past season I air layered a wild crab apple and in the spring I will be repotting it and getting all of the sphagnum moss off of the roots. I'm going to cut the wood back so all of the roots are on the same plane. I was wondering what tools you use to do this. I have a concave set of pruners and also a knob cutter, but I would prefer to get a smooth flat cut on the bottom. I'm not sure if this is necessary, but I was considering purchasing a trunk splitter tool because it's flat as opposed to the concave cut of the knob cutters. Is this necessary? I also have a small saw I can use.

For a smooth flat cut on the bottom, I just use a saw.

 

[HENDO]

If you don't already have a small hand saw and are looking for a good readily available one, check out the Silky Pocketboy. I have the Extra Fine blade and it's like cutting through butter regardless of the type of wood

 

[BrianBay9]

Sometimes it's hard to saw it flat high enough without damaging roots. In that case you can use your knob cutters and "nibble" the edges to get it pretty flat.

 

[jeremy_norbury]

There's always refinement of the cut so a rough cut with any old saw is generally sufficient to begin with.

 

[SeanS]

Sometimes it's hard to saw it flat high enough without damaging roots. In that case you can use your knob cutters and "nibble" the edges to get it pretty flat.

This is true. It’s not always possible to cut the layer right where you want it when separating, and it can be difficult to saw it once it’s removed as holding the layer firmly enough to saw it is near impossible once off the parent tree. I usually resort to a knob cutter.

 

[David P]

This is true. It’s not always possible to cut the layer right where you want it when separating, and it can be difficult to saw it once it’s removed as holding the layer firmly enough to saw it is near impossible once off the parent tree. I usually resort to a knob cutter.

View attachment 525446
View attachment 525447

Looks great, I have two layers on a Deshojo that I will be removing this spring, is it safe to remove the layer this time of year? you don't think the roots are to young and not hardened off yet to screw that plate on there? I always thought that after removing a layer you should just pot it and let the roots establish themselves for at least a year?

 

[SeanS]

Looks great, I have two layers on a Deshojo that I will be removing this spring, is it safe to remove the layer this time of year? you don't think the roots are to young and not hardened off yet to screw that plate on there? I always thought that after removing a layer you should just pot it and let the roots establish themselves for at least a year?

You have to be very careful but if the roots are at the right angle (fairly horizontal) I've had no issues screwing layers to boards/disks from the get-go.

Here's another I did the same to a few seasons back, and the resultant nebari 2 seasons later.

Separated and screwed to a plastic disk



1.5 seasons later




Last spring, growing well

 

[Shibui]

I always thought that after removing a layer you should just pot it and let the roots establish themselves for at least a year?

New roots are brittle so some 'experts' will advise to wait a year to allow them to harden up. That's the conservative approach. One drawback with this is that some roots may harden up and be more difficult to shape after the extra year. You may need to do some root pruning to get the desired result.
@SeanS has already shown pics to prove it is possible to work with much younger roots provided you are reasonably careful. Roots at that stage are more flexible to get the root arrangement you need.
It's up to you whether to follow the conservative route or try something else.

The air layer roots will probably be hanging down slightly so it is really difficult to get a saw in there to do a flat cut. You may even damage some roots trying. I also use the knob cutter to nibble away the stump. You don't have to do it immediately. The stub can be reduced over a number of years if you don't feel the need to get it on a board.
I've found the board unnecessary for layers. The new roots are already growing as laterals and that rarely changes as the tree develops. The few roots that do go deep can be pruned off during repotting.

 

[SeanS]

I will add that working the new roots like I’ve shown above is not for the squeamish. Fresh air layer roots seem to get stuck together or start to fuse quite easily so when working them at separation time they pop and crack as they move around

 

[Cajunrider]

Hello. This past season I air layered a wild crab apple and in the spring I will be repotting it and getting all of the sphagnum moss off of the roots. I'm going to cut the wood back so all of the roots are on the same plane. I was wondering what tools you use to do this. I have a concave set of pruners and also a knob cutter, but I would prefer to get a smooth flat cut on the bottom. I'm not sure if this is necessary, but I was considering purchasing a trunk splitter tool because it's flat as opposed to the concave cut of the knob cutters. Is this necessary? I also have a small saw I can use.

For air layers I often will take a thin sheet of material (1/4" plywood, or thin gauge metal) with a hole the size of the trunk. Then I gently work the roots to spread them out above the hole and push the trunk down as far as I can. Then I use an oscillating saw or a trim saw to cut the trunk flush with the hole. This allows me to cut the trunk flush while having the roots well protected.

 

[David P]

For air layers I often will take a thin sheet of material (1/4" plywood, or thin gauge metal) with a hole the size of the trunk. Then I gently work the roots to spread them out above the hole and push the trunk down as far as I can. Then I use an oscillating saw or a trim saw to cut the trunk flush with the hole. This allows me to cut the trunk flush while having the roots well protected.

I like this idea, great tip!

 

[Weta]

Here's me thinking the chainsaw will do.

 

[Cajunrider]

Here's me thinking the chainsaw will do.

Chain saw is too rough on the roots. A big band saw is the ticket for me.

 

[The Warm Canuck]

Is this a graph?

 

[jradics]

a coping saw is perfect. small and easy to handle and can be quite percise. Also can be had most anywhere for just a few bucks

 

[Bonsai Nut]

Saw first, clean up with concave cutters second, seal third. I seal my air-layers even though some say you don't need to.

I also second the silky saw recommendation. I own three of them.

 

[David P]

Saw first, clean up with concave cutters second, seal third. I seal my air-layers even though some say you don't need to.

I also second the silky saw recommendation. I own three of them.

There so many Silky Saws, which one do you recommend?

Saw first, clean up with concave cutters second, seal third. I seal my air-layers even though some say you don't need to.

I also second the silky saw recommendation. I own three of them.

Which saw do you recommend?

 

[dbonsaiw]

After spending 3 years mangling and killing various trees, I am a little afraid of my own bonsai shadow and tend to proceed cautiously. I now set my layers using a plastic ring below the layer so the roots grow radially (I find they grow fairly radially anyway). I set my layers using nursery pots, not plastic bags (when I can). I use shredded sphagnum moss. When it's time to remove the layer, I simply saw off the trunk below the nursery pot. I carefully remove the tree from the pot, moss and all, and just plop it into a bigger pot with bonsai soil to fill, without disturbing the roots. Next season, it gets a repot, roots are combed out/cut back and that lower piece of trunk below the layer is sawed off and then followed up with knob cutters. I'll even leave some moss if I feel I will lose an important root from combing too hard.

 

[Bonsai Nut]

There so many Silky Saws, which one do you recommend?

Which saw do you recommend?

I have the PocketBoy (130mm) and Gomboy (210mm) for bonsai. The blades are large teeth.

I also have a Bigboy (360mm) which is a full on pruning saw that I use when I am doing mountain bike trail work in the state park.

Once you buy the saw, you can buy replacement blades if you need.