AusBonsai

Several years ago I tried to air layer a tall cork oak. I ring barked the trunk, and after 2 years the cut had healed over. Last year I repeated the exercise, this time tying a piece of wire around the top of the ring barked section. This time the airlayer worked, with good roots along one side of the cut. The air layer pot is a 30 cm orchid pot. I had sprays on the air layer pot and the parent tree's pot to keep both growing.

Here are the pictures.
The branches with leaves coming out of the air layer pot are from below the air layer cut.
I exposed the cambium on the side with no roots and applied rooting hormone. If new roots don't grow I will do a root graft next season.
I plan to hollow out the trunk on the bottom (parent) tree and keep the left hand leader.
I may use this, or seedlings for root grafts.

Nice work Steve. Fingers crossed for you the other side sprouts roots

Thx Jarryd.

Yes, i hope it roots. If not, it gives me a use for the seedlings i have as root grafts.

Glad to hear you've finally had some success! you can get some roots on the other side.

Look at the bark on the trunk too!

what do you put down as being the cause of only one side growing roots? was it the sunny side? was the unrooted side the first/last section to heal over from the first attempt? I'm assuming the air layer was done at the same location
why did you tourniquet the already ring barked trunk? it just seems to me that the cambium wasn't completely removed the first attempt and tourniqueting the top would suit no purpose as the flow from leaves to roots has been severed. Interested in your thoughts

regards
Max

no idea wrote: why did you tourniquet the already ring barked trunk? it just seems to me that the cambium wasn't completely removed the first attempt and tourniqueting the top would suit no purpose as the flow from leaves to roots has been severed. Interested in your thoughts

He mentioned that the area that he ring barked the first time completely healed over. This time when he ring barked it, he wrapped wire around the heartwood that butted up against the cambium. It acts as a barrier so the callous grows away from the trunk instead of down it. I'll see if I can find an example photo.

cheers Jarad

Jarad's reply answers the question about using a torniquet.

Re No Idea's question, I have no idea why one side grew roots. After 1 failed attempt and several yearsof trying, 50% success rate is fine.