[Dingus] eucalyptus delgupta (Rainbow Eucalyptus)

[LittleDingus]

Alright...maybe it's worth starting a thread on these guys...if for no other reason than they grow so dang fast!

In 2019, I bought some rainbow eucalyptus seed.



I think I paid like $6.95 for that packet! Look how tiny those seeds are!!! There are literally like 1 million seeds in there! Well, maybe 100K? 10K? Friggin lots!

I couldn't find pictures of when they were first sown...but I have this picture of them from 8/3/2019.



I really didn't expect these guys to go anywhere...they have so negative traits against them as "bonsai". I don't have many pictures of them prior to this year because of that That's partly why I'm starting this thread...

By 10/4/2020...just over a year later, my "champion" rainbow looked like this:



Sorry, I don't have better pictures from that time

I had 2 bags of rainbows by that point. This one and a community bag of 3. I got a couple air layers off one in the community bag that are talked about in a thread elsewhere...

But, you can see the ugly bar branch on this one and that it tried to create a new leader out of that T several times over.

One of the problems with these guys is they wilt easily and catastrophically! I have two major problems trying to winter them:

1) They wilt...and they wilt hard and fast. If older leaves wilt...they are very likely dead Younger leaves seem more tolerant and can come back from some wilting...but older leaves tend to get crispy and die!

2) They seam to be pretty susceptible to white powder fungus. Mine lived through it last winter...but they struggled!

Some observations after the first 18ish months:

* They wilt...and catastrophically.
* They grow really fast!
* Despite many claims I've seen to the contrary: they can display colors when very young! The trick is to get vigorous enough growth to get the bark to split. The coloration is an oxidation reaction. Get the bark to peel...colors will form.
* The form ugly bar branches easily. Every one I kept up to the 18th month mark had bar branches. Not all were Ts. Some were Js. Branches have a tendency to dip before growing upward again.

I'm commenting these observations because I've recently started a new back that I'm hoping to avoid some of these issues with

 

[LittleDingus]

Now for 2021...

I had 4 trees at the beginning of the year. One "champion" planted alone and a community bag of "backups" sitting the bench

I planted one of the backups into a tiny pot to see how it would take it. The other 2 got composted...I needed to whittle down my collection prior to a planned move in the spring

The one moved into a pot started to wilt right away. I put the entire pot into a deep drip tray and filled it with water so the roots were submerged. That seemed to help fairly well. After a week I removed from the standing water and kept wet and eventually the tree started budding out and growing again. Then I went on vacation and it didn't get watered frequently enough and died Unfortunately, I didn't document that process very well...another reason for starting this thread: I've started batch #2 so want to remember what happened in batch #1 and adjust...better late than never!

By 6/6/2021, the bark on my champion has split and peeled away. I didn't take a picture right away...this was a few days later:



When it first split, the bark was a very bright green. After a few days in the sun, it faded to this reddish green. After two more weeks, it faded to this



And it's been growing so vigorously this summer that just in the past week or so, the bark has split and started peeling again!



You can see the bright green where the bark has already peeled and the piece that has popped but hasn't fallen off yet.

Over last winter, I was getting some purples and blues. I suspect how fast and under what conditions the fresh bark oxidizes plays some role in how it transitions through the spectrum from fresh bright green to old rustic brown.

Since the coloring is due to the new bark oxidizing, that also means it'll be difficult to get a "rainbow" on a small tree simply because the trunk is small enough big sections pop at once I also wonder what that means for a bonsai where the growth is slower...maybe slow enough the bark doesn't pop/peel much at all??

The tree is developing a nice radial nebari all on its own though



No buttressing or flare yet...but the roots seem well placed. Nothing crossing that I could find.

And 3/4" of an inch trunk after ~2.5 years is not bad!



It's in the same league as my redwoods anyway

Here's the full tree as it sits today.



Except for that stupid T branch, it's not entirely unpleasant to look at. The new leaves tend to come out purple which gives the tree an overall nice character. I've pinched new growth a couple of times this season to try and keep the tree a little more compact: it has to fit back in the house in a month or so.

Depending on what I decide with batch #2, I might air layer the sides of that T off next summer. I air layered one of the bench warmers last year and it layered really well! In fact, I got roots from BOTH sides of the layer!



I've never had that happen before...even on species known to ground layer themselves readily. What I have noticed is that there are many places on their trunks that have what look like nubs for aerial roots??



Last winter I wrapped one of the ones near the soil to keep it damp and see what it would do. Nothing. But it was also winter and too cool for much growth at the time. They don't look like foliage buds. They really do look like aerial root buds like often occur on ficus.

My understanding from research...which given how much other research doesn't match my observations with these guys ...is that they can root from cuttings very easily up until about 5 years old...then they become difficult to root from cuttings. What wasn't clear is if that was 5 year old wood (my assumption) or a 5 year old tree. Something I have to wait 3 more years to test out

Observations from season #2:

* Bar branches suck
* These things grow fast!
* I can water them twice a day and they still dry out the soil! But they seem a little more resistant to wilting once better established.

 

[LittleDingus]

The purpose of this thread is to document observations and mistakes for applied knowledge on a new set of seedlings I started a couple of weeks ago.



There are three different euc species in that pot.

Delgupta


Camaldulensis


Citriodora


I've also got some seed on order from overseas for some species I could not source in the US that I'm hoping to try.

My plan this time around is to be more diligent on adding movement (But not with wire! I've seen too many reports of scarring because of how fast these things grow!), removing bar branches, etc...The first time around I was thinking "grow a trunk and chop" as one might a maple. I didn't much care about "long and straight" because that's natural for rainbows anyway. I'll continue that route for the one large rainbow I have left, but my hope for these others is twisty/knotty/chewed-up-and-stuck-to-the-bottom-of-the-bus-seat-gummy...that's why they're known as gum trees, right?!?

 

[LittleDingus]

Finally, an update!

I dumped the seedling due to space/time constraints in a recent move. I'm thinking to restart that experiment next spring...although my indoor winter space is very much diminished in the new house

I moved just one of my older delguptas...a 3 year old. The rest got left behind

I was too lazy to take pictures at the time, but around mid August...which was way too late...I started a layer on the tree I kept. I thought if it worked, fine...two shorter trees are easier to get under lights than one taller tree If it failed...one shorter tree is easier to get under lights than one taller tree...but I'd be a little sad about it.

I was able to cut the layer by mid September...again, a little early maybe, but there were a decent amount of roots and I was hoping the tree would secure itself a little before coming in for the winter. It worked!!!

Here's the main tree today (well, yesterday when I took the picture)



My plan is to eventually cut that topmost bud on the right and try and sculpt the trunk to that top left branch. I'm hoping to get some branching back. It looks like that is going to happen...but winter might be rough

It's a little immature yet, but this guy has grown a decent nebari all on it's own:



It's in need of a repot which can hopefully happen next summer and hopefully I can get it into a wider and flatter bag to help those surface roots thicken more.

I'm noticing that being directly under the blurple lights seems to be helping to keep the internodes shorter:



I suspect the blue is inhibiting extension...it is certainly killing off chlorophyl and the leaves are remaining almost entirely purple! Something to keep watch on over the winter while it's under lights to compare to natural sunlight growth once it can move back outside in the spring.

For comparison, here's the layer that came off the top:



It's further away from the lights it's under...plus it's under a full spectrum LED so very much less blue.

The branch structure is a little more interesting on this one:



I don't care for the angle, but that's where the wind put it! It's fairly secure in the bag now, but I'm still just letting it be as much as I can to break as few roots as I can going into winter.

I'm quite happy with the colors that I get off such a young tree. I do think these need to be much larger to get a better display though. Mine tends to pop large sections of bark all at once...often completely around the branch too. The bark does go through the nice bright green "fresh bark" on to the darker greens and on into the purples and reds as the bark ages...but since it does it in large sections, the cool "rainbow" striping effect iconic in so many pictures is mostly lost.

Given my indoor space limitations, I'm not sure I'll ever be able to get mine to grow large enough to develop striping. I think mine will always remain blotchy. It's still a very interesting process to watch evolve And the green/purple leaves are interesting unto their own!

 

[Kievnstavick]

How is your tree holding up?

I found one of this in a botanical Garden while I was in Hawaii and I was enamored with it.

Below are two pictures that I took of it. You can see from the undercanopy shot that the branches seem to be bar branches.