Banksia root development question

[PWC]

I have a grown banksia that is just over 1 year old and not sure of the best way to develop the roots. This summer I plan to do the initial root work and repot. My question is regarding the large root that is winding around the trunk. Should I remove it completely or shorten it up?

IMG_2343 (Large).JPG

IMG_2342 (Large).JPG

[Grant Bowie]

Hmmmm,

Good question. Undoubtably if you leave it it will thicken and become more obvious. However it may just merge seamlessly and not cause a problem. Shortening it up wont help either way; you will still have the same quandary.

If you take it off will it make the tree unstable? If you decide to cut it off; check the stability and if it is wobbly shorten back the foliage to 2 or 3 leaves to aid stability. the next 6 weeks or so is a good time to work on Banksia.

Photograph and update so we can see where you go with this.


Grant

[PWC]

Thanks for the reply Grant,
I checked around the top layer of the mix and could see at least three other significant roots that should offer some stability. They are in the 2-3 mm thick range and spread around the tree. I think I would probably remove it completely and leave the rest of the root mass in place for another year.

[shibui]

Good news is that B. integrifolia respond quite well to root reduction so I would not be worried for the tree survival provided there are some other roots left.
If there are other adequate roots to support the trunk and removing this one enhances the tree I would be happy to go ahead.
If either of those factors are not met you could consider layering as that appears to be possible with banksia.

[MikeK]

If either of those factors are not met you could consider layering as that appears to be possible with banksia.

I concur with Neil that in my experience banksia (integrifolia at least) can be layered (admittedly, a sample size of 1 tree in my case)

Here's a ground layer I did on 29 Dec 2019 (it's in a 300mm orchid pot, so a reasonable size trunk).

Layer - cut.jpg

Layer cut site, with rooting hormone applied. I used Yates Clonex Rooting Hormone Gel - Red (hardwood)

Layer - wrap in sphagnum.jpg

Wrap cut site in layer of wet sphagnum

Layer - done.jpg

Done - mesh added and filled with Ray Nesci's Mix

Was left it a bit long as I only checked it again last weekend - 10 Oct 2020 (sorry, forgot photo's) and there was a huge mass of fine roots (most approx. 2mm diameter, few much larger) 360 degrees around the layer that completely filled the mesh and pot (not just the mesh section). Worked much better than I expected, given this was my first attempt at a layer of any sort.

The old roots below the layer had all pretty much died off, so was lots of fun trying to untangle everything. Next time I would probably layer in mid spring and check and hopefully cut back to the layer in mid summer.

[PWC]

Thanks Neil and Mike for the layer option. As it is still young I'll take the removal option first and see how it goes. If it doesn't give a good result I can layer it when it gets a more advanced trunk.

[Grainer]

Layering works.. I started 1 4 weeks ago and it has taken quite easily.

[PWC]

I have had a go at removing as much of it as I thought necessary, Might have gone a bit to hard time will tell( it always does). I did similar to a couple of smaller trees a month ago and they seemed to be going ok.

[PWC]

If it survives I plan to give these two a similar treatment, both seed grown 18 mths old.