Japanese Maples - options and advice for coming spring work

[Sir_Nixon]

Hello All,

I would love some advice/comments from everyone with my new maples that I have recently acquired from a nursery ($40 each!). Both maples were just hand dug from field growing for the last 4-5 years and was planning my next steps for this coming spring. I plan on practicing air layering with both of these at several locations along the tree once there tree is healthy and thriving, and will need to regrow new roots, since the roots on both trees are horrible and shoot straight down unfortunately.

1) Since they were recently dug from the ground, would it be smart this spring to clean the roots, ground layer or tourniquet above the existing roots and replant in the ground for a couple years to establish a new root system?

2) what would be the best technique to get new roots? tourniquet?

3) Also where would be the best place to truck chop after air layering? I have attached photos of the trees and some photos of where I would do the air layering and possible trunk chop options

Thanks for your input!!

 

[0soyoung]

Field grown roots can be very ugly, but no matter, you could leave your tree planted as is. it should be good for 2 or 3 years. Correcting field grown roots can be done by layering girdling or cutting back individual roots to ground layering off everything and starting over. The thing to keep in mind when layering is that girdling (ring barking) removes the pholoem or inner bark that transports carbohydrates. So, if you were to girdle one root, say, there will be no foliage below the girdle to feed it - those tissues below will survive on nothing but the starch grains they have stored. You might choose to ground layer on heavy root by removing a ring of bark from it in spring 2020, hear where it joins the tree, for example. Hopefully when you repotted in spring 2021 you would find enough roots to sever the old end, below where you had girdled and then you would similarly girdle another big root before repotting and be able to remove its old end in spring 2022 and etc. It is a very slow way to go, but also very safe as there are always other roots being fed - all, though, are supplying the tree with water and minerals.

This very conservative route may seem a bit silly. You may want to just cut to the chase by just girdling the trunk at or around ground level and with an acer palmatum it likely will work out that you could be sawing those field roots off in late summer 2020. But there is some chance that something goes wrong and there are not adequate roots then. By my experience, you can then only hope that there is by mid-summer 2021 or the tree will suddenly collapse because all of the roots have exhausted their stored energy and died --> you've lost everything! By contrast, had you layered just one big root, the worst case outcome would be that you just lost that one root - big deal, you could have just pruned it off an a. palmatum anyway.

The same concerns arise with air layering branches or portions of the trunk. There needs to be foliage below the (lowest) girdle to keep what is below alive. There needs to be foliage above because it is the accumulation of auxin from it that creates root tissues. I note that you have a branch below your intended air layer = good! You could make a bunch more next spring, if you want (foliage to feed what is below, foliage above to make roots).

Personally, this is what I've done before and what I would do now were this my tree, however, there is a bit more to think about. That is none of these trunk pieces will get much thicker until the apical stems you have left are nearly as thick. IOW, the trunk below you intended air layer will not get any thicker until that little twig gets to nearly the same size --> for several years. Lets just say you are good with that. the chunk you plan to layer off your tree has a lot of branches and hence will have a lot of foliage - this layer will thicken much faster than the bottom part. However, all that root work will be much easier to do with a much shorter tree.

I think I've belabored this enough for you to be able to think things through and decide what you want to do*.

Tourniquets are generally a waste of time as opposed to just girdling the stem. A tourniquet will induce flaring just above them, but on acer palmatums it is negligibly more than will usually occur above a girdle (ring bark) anyway. The cambium from the top of the girdle has a tendency to grow downward and will seemingly bridge the girdle. Some people apply a wire tourniquet on the bare wood at the top of the girdle to prevent this. Some BNuts have noted that this also seems to make the adventitious roots all go outward and not downward as they sometimes do.


*make you planned layer spring 2020, 'harvest' and pot it about Aug2020, start root correction of or ground layer the bottom spring 2021

 

[Sir_Nixon]

Field grown roots can be very ugly, but no matter, you could leave your tree planted as is. it should be good for 2 or 3 years. Correcting field grown roots can be done by layering girdling or cutting back individual roots to ground layering off everything and starting over. The thing to keep in mind when layering is that girdling (ring barking) removes the pholoem or inner bark that transports carbohydrates. So, if you were to girdle one root, say, there will be no foliage below the girdle to feed it - those tissues below will survive on nothing but the starch grains they have stored. You might choose to ground layer on heavy root by removing a ring of bark from it in spring 2020, hear where it joins the tree, for example. Hopefully when you repotted in spring 2021 you would find enough roots to sever the old end, below where you had girdled and then you would similarly girdle another big root before repotting and be able to remove its old end in spring 2022 and etc. It is a very slow way to go, but also very safe as there are always other roots being fed - all, though, are supplying the tree with water and minerals.

This very conservative route may seem a bit silly. You may want to just cut to the chase by just girdling the trunk at or around ground level and with an acer palmatum it likely will work out that you could be sawing those field roots off in late summer 2020. But there is some chance that something goes wrong and there are not adequate roots then. By my experience, you can then only hope that there is by mid-summer 2021 or the tree will suddenly collapse because all of the roots have exhausted their stored energy and died --> you've lost everything! By contrast, had you layered just one big root, the worst case outcome would be that you just lost that one root - big deal, you could have just pruned it off an a. palmatum anyway.

The same concerns arise with air layering branches or portions of the trunk. There needs to be foliage below the (lowest) girdle to keep what is below alive. There needs to be foliage above because it is the accumulation of auxin from it that creates root tissues. I note that you have a branch below your intended air layer = good! You could make a bunch more next spring, if you want (foliage to feed what is below, foliage above to make roots).

Personally, this is what I've done before and what I would do now were this my tree, however, there is a bit more to think about. That is none of these trunk pieces will get much thicker until the apical stems you have left are nearly as thick. IOW, the trunk below you intended air layer will not get any thicker until that little twig gets to nearly the same size --> for several years. Lets just say you are good with that. the chunk you plan to layer off your tree has a lot of branches and hence will have a lot of foliage - this layer will thicken much faster than the bottom part. However, all that root work will be much easier to do with a much shorter tree.

I think I've belabored this enough for you to be able to think things through and decide what you want to do*.

Tourniquets are generally a waste of time as opposed to just girdling the stem. A tourniquet will induce flaring just above them, but on acer palmatums it is negligibly more than will usually occur above a girdle (ring bark) anyway. The cambium from the top of the girdle has a tendency to grow downward and will seemingly bridge the girdle. Some people apply a wire tourniquet on the bare wood at the top of the girdle to prevent this. Some BNuts have noted that this also seems to make the adventitious roots all go outward and not downward as they sometimes do.


*make you planned layer spring 2020, 'harvest' and pot it about Aug2020, start root correction of or ground layer the bottom spring 2021

Thank you so much for taking the time to respond. when you say girdling a single root, is that the same process as air layering; removing the cambium, placing sphagnum moss round the removal site and waiting for tiny roots to grow at that particular location? Since these trees were relatively cheap, I would love to try this process to gain more experience with it.

Also with needing foliage below an air layer to keep the lower portion going, when I air layer at a place that I have marked, will that removal of everything above create more buds to pop out of the almost bare trunk? Would it be a better idea to air layer something higher up in the tree instead of just going straight for the lowest part? just in case everything fails?

 

[0soyoung]

... when you say girdling a single root, is that the same process as air layering; removing the cambium, placing sphagnum moss round the removal site and waiting for tiny roots to grow at that particular location? Since these trees were relatively cheap, I would love to try this process to gain more experience with it.

Yes, exactly.

Also with needing foliage below an air layer to keep the lower portion going, when I air layer at a place that I have marked, will that removal of everything above create more buds to pop out of the almost bare trunk? Would it be a better idea to air layer something higher up in the tree instead of just going straight for the lowest part? just in case everything fails?

Yes, it will, as long as there is a node below (buds are only at nodes, which are easily seen on acer palmatum). Thimann and Skoog taught us that 'decapitating' a branch removes the auxin source and releases the buds below. Girdling removes the supply of auxin in the polar auxin transport stream just like pruning (at the same point) does.

Things occasionally go wrong, so I've developed a personal habit of not cutting back beyond a visible bud and do the same when layering (if I care about foliage on the stub below as opposed planning to remove the remainder of the branch afterward). At this stage of your game, you should be a bit foolish, if I may say so. There is no way to know if you are being too cautious unless you push your envelope of comfort. As you said,

these trees were relatively cheap,

Practical experience isn't one of those things you can get with a Master Card.

 

[sorce]

I see where you're going with those spots, and I appreciate em.

But I'd get them later.

Starting out here.

Let them cut to twigs get a bit bigger.

Maybe take all these as cuttings for s&g.


Come in and thin it a bit and grow out more stuff for layers.
Then work this whole trunk down in appropriate segments till you reach the base.

Hopefully good leads will sprout to cut back to on the way down.

Sorce

 

[Shibui]

In the first tree cut option 1 will just make a trunk with some bends into a straight trunk as the branch you are cutting back to is almost in line with the lower part. That cut will add some taper but will not give a nicely shaped trunk IMHO. Cut 2 is not much better as it is really close to the existing bend which will virtually disappear as the trunk thickens and higher cuts will negate better taper.

Tree 2. Your proposed layer looks like it will give you another tree with a straight, taperless trunk. How desperate are you to fill your yard with such trees? Sorce's layer sites at least have potential to get a trunk with taper and some bends when you prune off the extra branches or you could layer even closer to the forks to try to get a multi trunk JM.

These trees are typical of fast grown trees - lacking taper and movement. In my experience the best option is to cut quite low and grow a new trunk from the resulting buds. Not always successful with JM as pointed out above. The way I see it there's a choice between sure average quality bonsai and possible better looking trees.

 

[Sir_Nixon]

I see where you're going with those spots, and I appreciate em.

But I'd get them later.

Starting out here.View attachment 275926

Let them cut to twigs get a bit bigger.

Maybe take all these as cuttings for s&g.
View attachment 275927

Come in and thin it a bit and grow out more stuff for layers.
Then work this whole trunk down in appropriate segments till you reach the base.

Hopefully good leads will sprout to cut back to on the way down.

Sorce

Thanks for the input. Makes total sense. I think layering my way down to the base seems like the best route to go and then when something sprouts up to go with that and work on the subpar roots by layering as @oSoyoung mentioned above.

With it being just dug from the ground, would it be possible to air layer this spring?, or would it be wise to let the tree establish itself in the new container and gain some strength before attempting any layering?

 

[sorce]

@oSoyoung

It's a zero. @0soyoung .

As long as leaves sprout it'll be ok to layer I reckon.

No hating in waiting though!

Sorce