post-mortem? (Dawn redwood air layer)

[butlern]

I picked up a Dawn Redwood (Schulman's Nordlicht cultivar) last spring. Really interesting foliage, but a painfully slow growing dwarf cultivar.

Anyway, in my excitement over the beautiful, soft foliage, and promising trunk/branch taper and branch structure, I never cleared away the soil to peek at the root flair/nebari. After getting it home, cutting off the top of the nursery container, and wiring some movement into the branches, I was saddened to see this terrible reverse taper below the original soil level:



So this spring I attempted to layer the tree, hoping to establish a new set of roots radiating from just below the first branch pictured above. I'm in zone 5b and the layer was started on April 21, 2018, just as buds were opening.

The tree fully leafed out and looked great for nearly two months... until this week. It started drooping, curling, shriveling:



I figured something was amiss, so I opened the plastic bag holding the moist sphagnum to see if the layer was a total failure. It appears to have been a failure, but I'm probing for feedback here from those who have direct, first-hand experience with layers.

The cambium calloused, but never sent out any roots (I did apply IBA when I made the incisions and before I wrapped it up last April)



Seems the original root system finally gave up the ghost... and there were no new roots from the layer to supply the foliage. Now there's no healthy foliage to feed the cambium. Really bummed about this.

Just wondering if it's worth re-wounding the cambium, wrapping it all back up, and dropping this sad tree in the shade in the hopes that it might throw roots sometime this year, and with proper winter protection, new leaves might emerge in the spring.

Thoughts?

Thanks in adbvance

Noah

 

[KiwiPlantGuy]

I picked up a Dawn Redwood (Schulman's Nordlicht cultivar) last spring. Really interesting foliage, but a painfully slow growing dwarf cultivar.

Anyway, in my excitement over the beautiful, soft foliage, and promising trunk/branch taper and branch structure, I never cleared away the soil to peek at the root flair/nebari. After getting it home, cutting off the top of the nursery container, and wiring some movement into the branches, I was saddened to see this terrible reverse taper below the original soil level:

View attachment 197071

So this spring I attempted to layer the tree, hoping to establish a new set of roots radiating from just below the first branch pictured above. I'm in zone 5b and the layer was started on April 21, 2018, just as buds were opening.

The tree fully leafed out and looked great for nearly two months... until this week. It started drooping, curling, shriveling:

View attachment 197073

I figured something was amiss, so I opened the plastic bag holding the moist sphagnum to see if the layer was a total failure. It appears to have been a failure, but I'm probing for feedback here from those who have direct, first-hand experience with layers.

The cambium calloused, but never sent out any roots (I did apply IBA when I made the incisions and before I wrapped it up last April)

View attachment 197074

Seems the original root system finally gave up the ghost... and there were no new roots from the layer to supply the foliage. Now there's no healthy foliage to feed the cambium. Really bummed about this.

Just wondering if it's worth re-wounding the cambium, wrapping it all back up, and dropping this sad tree in the shade in the hopes that it might throw roots sometime this year, and with proper winter protection, new leaves might emerge in the spring.

Thoughts?

Thanks in adbvance

Noah

Hi Noah,
Bit late now, but I would have “ground layered” this tree, by either putting tree into deeper pot to cover layer by 2-3 inches of soil, or placing a cut off pot on top of existing pot. I don’t think the air layer was the problem, as they layer easily, but probably too wet etc.

Hope the photo helps somewhat.
Charles

 

[GailC]

I don't know a thing about red woods but I wouldn't give up until the tree is crispy & dead.

You really have nothing to loose so rewound it and try to save it. I'd not only put it in the shade but also put it in a humidity tent.

I have to wonder if you did the layer to soon? When I layer deciduous trees, I wait until the new growth is hardened.

 

[butlern]

Hi Noah,
Bit late now, but I would have “ground layered” this tree, by either putting tree into deeper pot to cover layer by 2-3 inches of soil, or placing a cut off pot on top of existing pot. I don’t think the air layer was the problem, as they layer easily, but probably too wet etc.
View attachment 197106
Hope the photo helps somewhat.
Charles

Hi Charles,

I was aiming to avoid "new roots" growing into the existing medium (dense bark/compost/standard nursery soil), because they would never easily release themselves if/when I attempted to separate the layer.

Seems this worry is no longer an issue.

Perhaps it was too wet to throw roots from the cambium. I rinsed away the shredded sphagnum to take the photo, so it looks particularly saturated in the picture posted above. But still, that may have been an issue.

I wounded, re-applied IBA, and buried it all in pumice/sphagnum that is held in place by a cut off pot-top (the ground layer perhaps I should have started with).

There now is very little hope, but this last-ditch effort only cost me a quart of pumice.

Uggggh.

 

[M. Frary]

I believe the quest for perfect radial roots is the wrong way to think at times.
Trees in nature don't have perfect radial growing surface roots.
Yeah,yeah they say start from the ground up starting at the roots.
Ppffftt!
Personally it doesn't really matter to me if the tree is healthy.
I work with trees every day. Full grown ones. Not really seeing many cool rootspreads in the real world.
More trees don't have them than the ones that do. Like 99%.
I know bonsai purists won't like hearing this but it's true.

 

[bonsaichile]

I believe the quest for perfect radial roots is the wrong way to think at times.
Trees in nature don't have perfect radial growing surface roots.
Yeah,yeah they say start from the ground up starting at the roots.
Ppffftt!
Personally it doesn't really matter to me if the tree is healthy.
I work with trees every day. Full grown ones. Not really seeing many cool rootspreads in the real world.
More trees don't have them than the ones that do. Like 99%.
I know bonsai purists won't like hearing this but it's true.

It is true: In nature, trees dont have radial roots. BUT bonsai is not nature, it is art and culture. As such, bonsai trees are not "natural trees" but idealized versions of trees. and this is true whether you prefer the classic styles or the "naturalistic" style. Otherwise, nobody would care about taper, which is not at all common in nature!