Air Layering Thick T-Intersection Olive Branch

[Bonsilot]

I'm looking for advice on how to best airlayer a large T shaped branch on a European Olive (see photos). Questions below. Any tips or info on how long it will likely take would be greatly appreciated too.

Here's my current plan:

Make cuts on the branch at the red lines shown in the photos. Scrape off the cambium, apply Clonex rooting gel to cut site, bag it with wet sphagnum Moss, cover that with aluminum foil, and keep it moist for a long as it takes. I'm doing this in the beginning of Summer on the Central Coast of California.

Questions:
- Should I leave more room between the cuts because this is a larger branch (see photos)?
- How long does an airlayer of this size take to root (specifically for an olive).
- Is there anything I'm doing wrong or anything that I should do with a larger airlayer like this?
- Is there anything I can do to increase my success?

 

[BrianBay9]

If you make all three cuts indicated by the red lines you'll eliminate all the foliage that might support the right most cut. Also, air layering the horizontal section is likely to result in root primarily on the lower side of the branch. If you want the more vertical branch as your trunk, I'd only air layer at the top most (center) indicated area. Your more likely to get radial roots with that one.

 

[Bonsilot]

If you make all three cuts indicated by the red lines you'll eliminate all the foliage that might support the right most cut. Also, air layering the horizontal section is likely to result in root primarily on the lower side of the branch. If you want the more vertical branch as your trunk, I'd only air layer at the top most (center) indicated area. Your more likely to get radial roots with that one.

Both branches (the left and verticle) are well-developed and have lots of foliage. They should both have enough foliage to survive independently. (It was a bit difficult to get a good picture of the verticle branch's foliage.)

Here's my problem, I want to get the taper in the verticle branch. Airlaying higher up on the verticle branch would eliminate that taper. That's why I'm thinking of cutting almost flush with the horizontal branch. I couldn't care less about the branch on the left. That one will be cut off anyway because I need to prune the tree. I only care about the verticle branch.

Do you think just chopping the left branch before I airlayer would be better than leaving it while the air layer takes? Would that eliminate rooting on the lower side of the branch? I was considering leaving the left branch to provide shade to the air layer site.

 

[BrianBay9]

Both branches (the left and verticle) are well-developed and have lots of foliage. They should both have enough foliage to survive independently. (It was a bit difficult to get a good picture of the verticle branch's foliage.)

Here's my problem, I want to get the taper in the verticle branch. Airlaying higher up on the verticle branch would eliminate that taper. That's why I'm thinking of cutting almost flush with the horizontal branch. I couldn't care less about the branch on the left. That one will be cut off anyway because I need to prune the tree. I only care about the verticle branch.

Do you think just chopping the left branch before I airlayer would be better than leaving it while the air layer takes? Would that eliminate rooting on the lower side of the branch? I was considering leaving the left branch to provide shade to the air layer site.

You have to have foliage distal to the trunk (higher or our further) to drive root formation in an air layer. If you cut the cambium in all three locations, the cut on the left will lose all connection to any photosynthetic material from leaves coming down the phloem. Roots might form on the left and on the top, but not on the right.

Yes, I would layer the vertical section as close to its connection to the horizontal branch as possible.

 

[ShadyStump]

Only one girdle should be needed for an air layer, and it must be between the trunk and the branch you intend to keep.
I do not recommend something like cutting a circle around the base of the vertical branch into the horizontal. That's the area where the fibers of the cambium from the two merge, and Lord knows what will happen.

You could place your girdle on the right-hand line, and just take the whole thing. Then prune off the outer end of the horizontal when it's time to pot. You won't get the nice radial roots, but you should get plenty of them inside the season.

 

[Bonsilot]

You have to have foliage distal to the trunk (higher or our further) to drive root formation in an air layer. If you cut the cambium in all three locations, the cut on the left will lose all connection to any photosynthetic material from leaves coming down the phloem. Roots might form on the left and on the top, but not on the right.

I understand there needs to be foliage. You can't get roots on the "bottom" of an airlayer cut.

I think this picture will help explain better. There is substantial foliage on both branch #1 and #2. I just need roots on branch #1.

I'm just wondering if it would be better to chop off branch #2 entirely before airlayering?

 

[Bonsilot]

I do not recommend something like cutting a circle around the base of the vertical branch into the horizontal. That's the area where the fibers of the cambium from the two merge, and Lord knows what will happen.

Wouldn't an intersection better the branches be an optimal location for a cut since there's more "activity" (for lack of a better word) there?

I was thinking it's similar to how people recommend airlayering slightly below branches or nodes on Japanese Maples.

I included a little clearer picture of what I'm trying to do. I just want branch #1. Couldn't care less about branch #2.


Also, thanks for the advice

 

[ShadyStump]

Wouldn't an intersection better the branches be an optimal location for a cut since there's more "activity" (for lack of a better word) there?

I was thinking it's similar to how people recommend airlayering slightly below branches or nodes on Japanese Maples.

I included a little clearer picture of what I'm trying to do. I just want branch #1. Couldn't care less about branch #2.


Also, thanks for the advice

It's that there's no telling what activity there is.
There are plenty of people with more experience than me, but that's my working theory for now. I suspect your chances of success doing it would vary by species.

 

[Shibui]

I would tackle this layer just as shown in the diagram. Branch 2 is not wanted so it can die no problem. I might even cut it off to make layering easier.
#3 comes from the tree. It will not root and will continue to grow supported by tree trunk and roots - no problem.

Can't help with how long as I have never bothered to layer olive. If I need an olive I just drive round the roads and pick a feral seedling to dig. In any case layering times are always fuzzy because timing depends on seasonal conditions, individual tree genetics, operator skill, and so many other variables. Just do the layer and keep checking until you have roots or failure.

 

[Bonsilot]

Mini-update: I think the layering went great! The picture w/ the text is after my rough cuts. I cleaned up the cut lines and removed the cambium after that.

I decided to keep both branches, in hopes of getting a bonsai and a partially grown olive out of branch #2.

If I remember, I'll let everyone know how everything turns out

 

[leatherback]

Late to the party. I cannot help but wonder why you airlayer? Olives root even as a big lump cutting without leaves.

 

[Shibui]

Late to the party. I cannot help but wonder why you airlayer? Olives root even as a big lump cutting without leaves.

I have seen lots of references and therefore tried a number of times but have not been able to root cuttings any size, except when flat bottom cutting dug up trees.
Cut through the widest part of the lignotuber, even with no roots present these still survive and grow new root system but branch cuttings?????????

 

[leatherback]

I have seen lots of references and therefore tried a number of times but have not been able to root cuttings any size, except when flat bottom cutting dug up trees.
Cut through the widest part of the lignotuber, even with no roots present these still survive and grow new root system but branch cuttings?????????

Interesting!

A friend of mine chopped a big olive in sections and all of them rooted.
I myself gave rooted a big chunk, but that was a section that came out of the lower part of a trunk.

 

[Bonsilot]

Late to the party. I cannot help but wonder why you airlayer? Olives root even as a big lump cutting without leaves.

A few reasons.

First, I have to prune this tree anyway, so I might as well try to make use of the branches. Second, the top branch has a great tapered base. And lastly, the airlayer will be quicker to develop than a cutting (which would take a several years to reach a to 4 inch thickness).

 

[Shibui]

And lastly, the airlayer will be quicker to develop than a cutting (which would take a several years to reach a to 4 inch thickness).

@leatherback point is that olives have a reputation for striking as very thick cuttings so a 4 inch cutting is definitely a possibility (except for me perhaps?) and rather than layering he would just chop that branch and root it as a cutting.

 

[leatherback]

@leatherback point is that olives have a reputation for striking as very thick cuttings so a 4 inch cutting is definitely a possibility (except for me perhaps?) and rather than layering he would just chop that branch and root it as a cutting.

Buuut.. As is clearly demonstrated in this thread.. Success rate may vary

 

[Bonsilot]

Buuut.. As is clearly demonstrated in this thread.. Success rate may vary

I actually didn't know rooting a branch that large for an olive was an option (just looked up a thread on it). I just assumed it wasn't possible. But that's good to know!

This cutting is definitely high up in the canopy. In addition, it's getting close to summer in CA. I expect higher temperatures in 2-3 weeks. And it'll probably be a hot summer. It might be better just to keep it on the tree, so it can continue getting supported.

I've already started the airlayer for a week, so I'm going to stick with it. If it doesn't work out, next year I can probably just cut a little higher and root the branch as a cutting like you're saying

 

[Bonsilot]

2 Month Update:
The airlayer is doing well and has roots.

- I've been watering the airlayer every 1.5-2.5 weeks in 75-83° weather. I've poked 4-5 holes over the length of the airlayer to water thoroughly. The airlayer has remained quite moist.

- I removed the tinfoil shielding the airlayer because about 40+ earwigs made their home under it. However, I did leave a sheet where most light hits the layering.

- I can see roots above the airlayer (see pictures), and faint white bubbling at the very top of the moss. I have added more moss to cover the exposed roots just in case.

Notes:
- The airlayered branches have lost about 1/3 of their leaves -- especially the branch in the most sun.
- There's budding a few inches below the airlayer (see picture).

 

[milehigh_7]

I have heard of folks chainsawing an entire tree and moving it to a new place and they apparently root just fine. So this should work great.

 

[nuttiest]

I have seen lots of references and therefore tried a number of times but have not been able to root cuttings any size, except when flat bottom cutting dug up trees.
Cut through the widest part of the lignotuber, even with no roots present these still survive and grow new root system but branch cuttings?????????

Yep, root a big fat olive is just another Japanese bonsai hazing ritual!
I am down to 1/2 pencil size before getting cuttings to root.