Impossible Question to Answer

[Gabler]

Pomegranate takes well from cuttings and are perhaps one of the more resilient for field growing, much like Trident Maple. They will fatten up quickly in the ground provided they get enough water and nutrients. If you decide to plant some, I'll hit you up in 10 years for a tree.

I'm in zone 7.

 

[Gabler]

I've wanted to play with the American snowbell for a while, but it seems less cold hardy than the Asian species and I've never found anyone selling it. Halesia caroliniana looks really cool and would be fun

I've seen a couple of people growing various Aronia, especially Aronia melanocarpa 'Brilliantissima'. Not sure how well it propogates, but it has wonderful fall color, nice winter berries and low disease pressure

Gary Clark was really enthusiastic about chalk maples (Acer leucoderme), and his collected ones at the winter silhouette show had a lot of potential. Super tiny internodes and Gary said their vigor is similar to tridents

There's got to be a deciduous oak species that'll work for bonsai, though I don't have any ideas on which ones to try

I haven't heard of chalk maples. I'll look into them.

As for deciduous oaks, Quercus phellos seems to be a good option. I also have some Quercus lobata x macrocarpa that I'm testing out. The leaves look like valley oak, and it's cold hardy.

 

[bonsaiwood]

I'm in zone 7.

Pomegranate Production

Pomegranates have been grown as a common backyard crop for decades in the South. In recent years, there has been an increased interest in the commercial production of the fruit in Georgia and surrounding regions. This production increase is largely in response to increased demand for the fruit...

extension.uga.edu

There are varieties hardy enough to grow in Zone 7, possibly Zone 6 with sufficient cold protection. Russian Pom comes to mind.

 

[Gabler]

Pomegranate Production

Pomegranates have been grown as a common backyard crop for decades in the South. In recent years, there has been an increased interest in the commercial production of the fruit in Georgia and surrounding regions. This production increase is largely in response to increased demand for the fruit...

extension.uga.edu

There are varieties hardy enough to grow in Zone 7, possibly Zone 6 with sufficient cold protection. Russian Pom comes to mind.

Hardy to 7°F, and it prefers temperatures above 85°F for more than 120 days per year.

 

[Timbo]

Dawn redwoods are interesting, but I'm not sure I understand why I would grow one when I have the option to grow bald cypress.

I prefer them to a Bald cypress. At least for me they are hardier than a Cypress, grow much faster, and air-layer much better. I'm a Fanboy of Dawn Redwoods.
Only a few other seedlings/trees I've had grow faster than Dawn Redwoods. Only issue is damping off on new seedlings, after a few weeks they are fine.

 

[Timbo]

This list could be very long LOL.
Some of these have been stated and I 2nd them.
Dawn Redwoods for sure.
Pinus sylvestris, Pinus banksiana, both have pretty small needles.
Ulmus parvilolia 'Elsmo', bark looks pretty cool.
Morus alba var. tatarica
Sorbus alnifolia, Sorbus intermedia
Cercidiphyllum japonicum,
ALL Zelkova's (If you can find seeds)
ALL Larix, sooo many cool alt larches to the Japanese.
I've been wanting to try Pseudolarix amabilis.
Ostrya virginiana, the bark is so unique and cool looking. Hard to get collected to bud out the next year though. Try cutting it at live branches/buds.
Some of the hardier Acer's like:
Acer mono,
Acer tataricum subsp. ginnala 'Flame'
Acer truncatum

I wish people used Cercidiphyllum japonicum more, they are pretty cool, the fall color is very nice. Very delicate seedlings though, but they ramp up fast.

I think all these could be used for Bonsai, some would be harder than others for sure.

All of these except Ostrya virginiana are fast growing which I like!

 

[hsaintandre]

I'd suggest Luma Apiculata. There are people growing it as a bonsai here and apparently it has been naturalized in your zone.

I don't know if it's a great species but I personally love them, and would definitely buy one if I have the opportunity.
It reminds me of my childhood, we'd often go to Patagonia for holidays and visit Los Arrayanes National Park. It's said that you have to hug them, I don't remember the reason, but I do remember the trunk being particularly cold although ambient temperature was 35°C.

 

[ponderingsage]

I am growing out shimpaku and JBP specifically as mother stock for grafting onto collected native material with poor foliage or for size/scale reasons.
This may be in demand with the increased focus on collected material(although hopefully not too much demand).

My other thought is growing things stylistically different than what is typically done like a trident maple that isn’t a wizard hat trunk, but more naturalistic with branching subtrunks… that’s my other growing projects right now

 

[Gabler]

My other thought is growing things stylistically different than what is typically done like a trident maple that isn’t a wizard hat trunk, but more naturalistic with branching subtrunks… that’s my other growing projects right now

I agree that stylistic variation is important. I don't want all trees to look the same.

I have nothing but rude things to say about grafted trees, so I'll stop typing now.