Did I just violently kill my pre bonsai Dawn Redwood?

[fossiliferous]

Hello, I’d like to report my first tree murder, I think, unless a quick intervention can save it. I essentially have a beautiful young dawn redwood… with no roots. Can I encourage it to sprout more or is it done for?
Not bonsai but pre-bonsai. I have three young children including a baby born this summer so I don’t have a lot of time yet to fiddle delicately with little trees, but everybody says they wish they started their trees sooner. I figured I have nothing but time for the next 5+ years to fatten some trunks up in the ground for bonsai!
My unfortunate victim was shipped to me in March with another dawn redwood as a bare root twig and had grown to about 3 feet high over the summer. I planted my pre-bonsai trees in my mom’s raised garden bed since this spring we were still looking for a house after selling.
Moved to the new place a couple of months ago. My mom wanted me to get my plants out of her garden as soon as possible so she could work on prepping everything for winter. Today was a beautiful day so it was time!
I had seen people planting things outside in plastic crates or pond baskets so back in March I figured I would try that. I knew I would be transplanting the trees soon and it seemed like it might make the transplanting process easier and might help keep the roots slightly contained without completely walling them off like a solid pot.
Unfortunately, the plastic crate was this tree’s undoing. I tried to dig around it but it was just stuck. I finally gave the crate a good yank and it came free, but alas, my tree did not come with it! Turns out it had grown a massive taproot reaching deep into the soil, and that taproot was going NOWHERE. These raised garden beds are on top of normal dirt and obviously the root reached all the way through the bed into the tough, cherty clay below. Instead of coming up with the crate, the tree was anchored by that taproot and so was pulled through one of the holes in the crate, stripping off fine roots.
My dad was nearby wrangling my 2 year old and came over to help. He used his pocketknife to make a clean cut but I don’t think he realized the tree had essentially been “sucked” through the crate and there weren’t roots above where he cut. I don’t think there is a single root left. I haven’t pulled what’s left of the tree out of the crate though in case there is something left I could risk damaging.
This was about three hours ago. The cut part tree has been down in a damp plastic bag ever since.
Is there any hope of this thing sending out new roots, and if so, what can I do to maximize it? Should I cut off most of the crown? Any point in breaking out some rooting hormone? Should I keep it in the garage over the winter, or is it a lost cause?
Heck, since the huge thing probably isn’t viable I could cut it up and try to get multiple separate branches/segments of the thing to form roots in case any of them are successful if that seems likelier.
For whatever it is worth, the other dawn redwood which was planted next to the edge of the garden bed only grew to be a little over a foot tall and had a much more reasonable root system without a massive taproot extending into the abyss.
I have attached pictures of the current situation of the tree, what the cut end looks like, and what the remainder of the stripped big root looked like where I had to leave it.
Thanks for any help!

 

[andrewiles]

Dawn redwoods root quite easily from hardwood cuttings, and it sounds like that's what you've got right now. So I'd treat it like a hardwood cutting.

I'd remove the leaves, which should be thinking about falling off now anyways. You should see lots of remaining buds for next spring. I'm not sure what zone you're in, but generally you'll want to keep the cutting (or cuttings, if you create more than one from the parent) cold and somewhat humid. You'll want them to stay dormant until next spring. For me in zone 8 that's just leaving them outside, stuck a few inches each into a tray with potting soil. I take them into the garage when it drops below 30 or so. In the spring keep them in shade until you see a second flush -- the first flush will take place without roots.

Also, if it really was cut off above the ground you should see if you can dig up the original trunk. Might also be a viable plant.

 

[fossiliferous]

Dawn redwoods root quite easily from hardwood cuttings, and it sounds like that's what you've got right now. So I'd treat it like a hardwood cutting.

I'd remove the leaves, which should be thinking about falling off now anyways. You should see lots of remaining buds for next spring. I'm not sure what zone you're in, but generally you'll want to keep the cutting (or cuttings, if you create more than one from the parent) cold and somewhat humid. You'll want them to stay dormant until next spring. For me in zone 8 that's just leaving them outside, stuck a few inches each into a tray with potting soil. I take them into the garage when it drops below 30 or so. In the spring keep them in shade until you see a second flush -- the first flush will take place without roots.

Also, if it really was cut off above the ground you should see if you can dig up the original trunk. Might also be a viable plant.

I want to apologize for not replying at the time, I thought I did but it looks like I merely read it and didn’t even like your post. So I apologize for that. I did file away your advice though with good results. I just wanted to post a quick update and say thank you for the advice. My cutting has survived so far. The buds are growing on the ends of the twigs, and it’s looking pretty healthy actually! I put it outside but kind of protected in a cardboard box for now on the shady side of the deck. If we have another hard freeze, which I’m sure we will despite balmy weather lately, I’ll put it in the garage. I pretty much have tried not to mess with it much other than making sure it stays moist.

I told my parents I would like the rooted end to the plant if it could be salvaged. I went out there a couple of weeks ago when they were going to put new dirt in the garden and we were going to try to pull it out. It’s a pretty shattered broken end though, and when I scratched at the bark, there was no green underneath. Just dry like an old twig.
When the weather gets a bit warmer I can try to plant my salvaged one a bit more in the ground perhaps. Thank you again for your tree-saving advice!