The science of air-layering

[cbroad]

Sphagnum Moss for this years propagating.

I usually use straight chopped sphagnum for air layering, but last year I tried mixing it with at least 50% perlite and was very satisfied with the results.
No issues with wonky roots other than when they hit the side of the bag and turn downwards.

In my opinion, this is the best substrate to use other than an aggregate; I know I couldn't keep that watered enough during our summers here.

For my purposes, 50/50 sphagnum/perlite works very well, and I'll probably always use this for my future air layers. I'm also using this mix for stratifying seeds, and seems to work pretty well so far...

 

[jmw_bonsai]

I usually use straight chopped sphagnum for air layering, but last year I tried mixing it with at least 50% perlite and was very satisfied with the results.
No issues with wonky roots other than when they hit the side of the bag and turn downwards.

In my opinion, this is the best substrate to use other than an aggregate; I know I couldn't keep that watered enough during our summers here.

For my purposes, 50/50 sphagnum/perlite works very well, and I'll probably always use this for my future air layers. I'm also using this mix for stratifying seeds, and seems to work pretty well so far...

I agree, if I am going to be able to use a pot or some other container on nicer material I plan on using that mix. I do lots just for fun since my prune happy wife will get them anyway, LOL. SO they are all over the yard in tough positions, so just being able to slap a ball of moss on is a little easier than setting up a container with moss/perlite mix. Plus with travel, I usually do mine then wrap and let go for the summer. No time to check and water, etc.
But for nice trees I really want for Bonsai and ones in containers easy to get to, I plan on doing pot/container set ups and will move the trees to locations with daily water so I wont need them to be so enclosed.

Getting a cleaner root system is one of the reasons I am trying the nice long fiber sphagnum moss this year and will be trying some mixed with perlite!

 

[Jorow99]

I have a question about large air layers. If you are trying to air layer a decently sized tree, 4"+ diameter and 20' tall, it doesn't seem feasible (or at least practical) to leave all the foliage on it. The slightest wind will catch foliage mass and tear all the new tiny roots or knock the tree over after separation. When is the ideal time to cut the tree down to size? If you chop it before the air layer, the tree will have a larger pool of resources to pull from to form new buds, branches, and foliage at the chop site. But now the tree will develop roots more slowly since the foliage mass has been reduced. This is the method I am trying currently at my home with multiple siberian elms.

I could also understand starting an air layer after the tree has pushed in the spring, letting the roots form, then chopping the tree but without removing the air layer. Then the tree could pull from the original and new roots to form new foliage mass, while already having a quickly developed root mass ready to be removed.

 

[leatherback]

4"+ diameter and 20' tall,

Why are you air layering this? Sounds to me like a telephone pole.

I would trim it back. Let is work on overgrowing the chop site and growing a new leader for one or two years. Then layer.

 

[BrianBay9]

I have a question about large air layers. If you are trying to air layer a decently sized tree, 4"+ diameter and 20' tall, it doesn't seem feasible (or at least practical) to leave all the foliage on it. The slightest wind will catch foliage mass and tear all the new tiny roots or knock the tree over after separation. When is the ideal time to cut the tree down to size? If you chop it before the air layer, the tree will have a larger pool of resources to pull from to form new buds, branches, and foliage at the chop site. But now the tree will develop roots more slowly since the foliage mass has been reduced. This is the method I am trying currently at my home with multiple siberian elms.

I could also understand starting an air layer after the tree has pushed in the spring, letting the roots form, then chopping the tree but without removing the air layer. Then the tree could pull from the original and new roots to form new foliage mass, while already having a quickly developed root mass ready to be removed.

You can certainly reduce the top when you separate the air layer from the mother plant. Don't take off all the foliage, but you can cut it back to something manageable. Your second option is to develop the structure of your future tree while it's still on the mother plant, before you air layer. Prune back, heal large cuts, establish primary branching - all will go faster on the parent tree. Then, right before air layering, let the growth run wild to produce additional foliage to drive the air layer root formation.

 

[Jorow99]

Why are you air layering this? Sounds to me like a telephone pole.

The part I am chopping off is the part that looks like a telephone pole. These are trees on my property that have been chopped multiple times by the previous owner so they are pretty gnarly and interesting. They have not been chopped recently though.

 

[Jorow99]

You can certainly reduce the top when you separate the air layer from the mother plant. Don't take off all the foliage, but you can cut it back to something manageable. Your second option is to develop the structure of your future tree while it's still on the mother plant, before you air layer. Prune back, heal large cuts, establish primary branching - all will go faster on the parent tree. Then, right before air layering, let the growth run wild to produce additional foliage to drive the air layer root formation.

I like this idea. I have a few I already chopped so I may try a couple ways and see which one works better.

 

[Saddler]

When I did Acer saccarum that were about that size, I airlayered just below a branch with lots of buds and when it came time to cut the layer, I cut off what I didn’t want and had the branch to support the roots and vice versa. They all worked out very well 3-4 years later.

 

[Forsoothe!]

When I did Acer saccarum that were about that size, I airlayered just below a branch with lots of buds and when it came time to cut the layer, I cut off what I didn’t want and had the branch to support the roots and vice versa. They all worked out very well 3-4 years later.

A picture would be instructive.

 

[Saddler]

A picture would be instructive.

Sorry, I can’t find any pictures of it. Just leave a branch that will have buds above the airlayer and below where you cut the top off.

Also, use lots of growing medium in your airlayer. With that much foliage above it, it will likely push a lot of root growth.

 

[Jorow99]

These are the trees I was referring to.

 

[BubblePopScott]

Hi, I've got my 1st air layer just showing signs of roots. Just about to hit winter here but mild winters. Should I wait till after spring to separate to allow for more root growth?

 

[leatherback]

Hi, I've got my 1st air layer just showing signs of roots. Just about to hit winter here but mild winters. Should I wait till after spring to separate to allow for more root growth?

How long till you expect trees to go bare?
If you have another 4-6 weeks before clear leafdrop I would separate. But I am an early lopper.

 

[BubblePopScott]

Tree is an evergreen, I would expect 4 weeks for trees to go bare. My winters are mild- no freeze just some frosts every now and then

 

[sorce]

Tree is an evergreen, I would expect 4 weeks for trees to go bare. My winters are mild- no freeze just some frosts every now and then

Leave it.

Sorce

 

[sorce]

I like this idea. I have a few I already chopped so I may try a couple ways and see which one works better.

I like this idea too but there's really no telling what each individual tree may do.

I've had success biwayily..both ways!

Are you against cutting the rest of the tree down?
It'll give you better access.
And a load of new sprouts to form for futures!

Sorce

 

[BubblePopScott]

Leave it.

Sorce

Thank you sorce, how do I know when I should take it off?

 

[BubblePopScott]

I should say I started the layer in october - early summer. Graft has been on 5-6 months now.

 

[Jorow99]

Hi, I've got my 1st air layer just showing signs of roots. Just about to hit winter here but mild winters. Should I wait till after spring to separate to allow for more root growth?

Leave it, the roots are super loaded with sugars so even if it did freeze the roots will be just as, if not more, frost resistant than regular roots.

 

[sorce]

Thank you sorce, how do I know when I should take it off?

The most important thing about an airlayer is making a window thru which you can check progress.

When the roots are full at the window!

Around your regular repotting season if possible.

Rain and Wane sure!

I am close to digging more yard stuff...and removing groundlayers come to think of it...since the leaves are almost opening, buy the waning moon isnt for another week or so....decided waiting is better.

Sorce