Cold Hardy Bonsai in Zone 3-4

[Viridian Bonsai]

Hello everyone,

So I have started really getting into bonsai this year. I do have some trees I began training/growing out to thicken 2 years ago: 2 shimpaku and 1 Blue Point chinensis. I will list the species I have and am starting from seed to ask their suitability as bonsai in this cold climate(zone 3-4). I realize that starting from seed and cuttings is an extremely slow and tedious way to start bonsai, but I am very young at 19 and am extremely passionate of growing these trees into something over my lifetime. As the Chinese Proverb says: The best time to plant a tree was 20 years ago. The second best time is now.

Starting from seed:
Dawn Redwood
Scots Pine
Limber Pine
Pitch Pine (Is this pine double flush?)
Korean Maple
Amur Maple
A. Rubrum

Started from cuttings:
Ginkgo
Korean Maple
Sonare (J. Procumbens)

Trees I've had for 2 years:
J. chinensis 'Blue Point'
Shimpaku
Shimpaku 'fudu' (this one has tight foliage like my other shimpaku but is far more blue in colour)

Collected Material from Spring 2021:
2 Douglas Maples
1 Lodgepole Pine

These trees seem to be hardy to my climate with modest winter protection such as mulching and shielding from wind by the side of the house. Since I am at university my collected trees and Prebonsai are at my mother's house where she is taking care of them over the winter.

I also have some other trees I am interested in but unsure if they would be hardy to my climate such as JRP, JWP, Hinoki, and Magnolia stellata.

Thanks everyone,
Viridian.

 

[PA_Penjing]

Hoooo doggy, you live in an excellent climate for some bonsai super stars. All larch species commonly used in bonsai will flourish up there. Nearly the entire genus of spruce (picea), engelmann is especially beautiful. Jack pine is a good one. I don't know anything about fir (abies) but they might be worth a fiddle if you can collect some for free. Not to mention the native deciduous like ulmus americana and northern hackberry. Rocky mountain juniper would do well to. Any of the northern native pines are great. I saw you listed limber but ponderosa and lodgepole are great too

 

[Viridian Bonsai]

Hoooo doggy, you live in an excellent climate for some bonsai super stars. All larch species commonly used in bonsai will flourish up there. Nearly the entire genus of spruce (picea), engelmann is especially beautiful. Jack pine is a good one. I don't know anything about fir (abies) but they might be worth a fiddle if you can collect some for free. Not to mention the native deciduous like ulmus americana and northern hackberry. Rocky mountain juniper would do well to. Any of the northern native pines are great. I saw you listed limber but ponderosa and lodgepole are great too

Haha, thanks! Up here it seems like mainly conifers will be my go to then! I forgot to mention I had also started some Tamarack and blue spruce from seed! Do American elm leaves reduce? There are a lot planted around here I can take cuttings from. What do you think of Siberian elm? There are lots as street trees as well!

I'm glad there are some neat species I can tap into that will survive in my climate since I was bummed out that many of the traditional Japanese bonsai species won't survive here.

 

[PA_Penjing]

American elm will reduce to around 1" so will hackberry. Both those trees are much hardier than siberian elm. I haven't used siberian elm because it's said to be a cruddy version of chinese elm which grow well for me. But certainly wouldn't hurt to try

 

[Viridian Bonsai]

Neat! I’ll take some cuttings next summer then

 

[HorseloverFat]

American elm is great!

They die in containers here, without Slight/moderate winter protection... I’m in Zone 5.. just so you are aware...

 

[HorseloverFat]

For areas “Zone 5” and colder... finding out your species’ “Root Damaging Temperatures” is FAR more useful than hardiness zones.

 

[HorseloverFat]

I was bummed out that many of the traditional Japanese bonsai species won't survive here.

If you like conifers... they do way better in the cold.. (Obviously tender conifers exist)..

I’ve observed many localized adaptations to cold wind in Picea and Tsuga species...

Larix are SUPER beefy and will take it well.

Check willow species.. most are resilient, WILL reduce and ramify well.. and are super adaptable to cold-life in containers.

Even Acer Rubrums die in containers without winter protection in MY climate.

Check what local landscapers use as hedging in your area...

 

[Viridian Bonsai]

For areas “Zone 5” and colder... finding out your species’ “Root Damaging Temperatures” is FAR more useful than hardiness zones.

Yes for sure. The plan is to eventually have a better system for winter after I'm through engineering. Some sort of heated greenhouse where I can even possibly grow some Japanese maples and JBPs. I'm starting some more cold hardy plants from seed and cuttings a few years before that so I can have some good starts by the time I'm through school.

 

[Viridian Bonsai]

If you like conifers... they do way better in the cold.. (Obviously tender conifers exist)..

I’ve observed many localized adaptations to cold wind in Picea and Tsuga species...

Larix are SUPER beefy and will take it well.

Check willow species.. most are resilient, WILL reduce and ramify well.. and are super adaptable to cold-life in containers.

Even Acer Rubrums die in containers without winter protection in MY climate.

Check what local landscapers use as hedging in your area...

The seeds are I got for Amur maple, Rubrem, and Korean maple are from locale plants in the city. The Ginkgo and Sonare cuttings are also from street trees so I assume they will be hardy enough with protection.

 

[HorseloverFat]

American elm will reduce to around 1" so will hackberry. Both those trees are much hardier than siberian elm. I haven't used siberian elm because it's said to be a cruddy version of chinese elm which grow well for me. But certainly wouldn't hurt to try

Yes! Good call on hackberry..

I have a SugarBerry, which IS a HackBerry (I believe).. and it survived FALL collection, aaaand exposed winter, in a terra cotta, frozen solid in Ice.

Exploded with growth in the spring... but fast became an aphid magnet... it’s super healthy!.. they just like the density of the wood, and the higher concentration of sugars.

 

[HorseloverFat]

The seeds are I got for Amur maple, Rubrem, and Korean maple are from locale plants in the city. The Ginkgo and Sonare cuttings are also from street trees so I assume they will be hardy enough with protection.

Absolutely! If your “ME” or colder.. just assume you have to protect EVERYTHING.. somewhat.

@berzerkules is in 2

 

[HorseloverFat]

Yes for sure. The plan is to eventually have a better system for winter after I'm through engineering. Some sort of heated greenhouse where I can even possibly grow some Japanese maples and JBPs. I'm starting some more cold hardy plants from seed and cuttings a few years before that so I can have some good starts by the time I'm through school.

Although this is a great plan in foresight, I would focus on, FIRST.. being able to successfully over-winter local plants and “locally zoned” plants... find your “baseline”... or you’ll never really understand the parameters of your climate.

For cold-folk, this is of UTMOST importance.

 

[Viridian Bonsai]

Although this is a great plan in foresight, I would focus on, FIRST.. being able to successfully over-winter local plants and “locally zoned” plants... find your “baseline”... or you’ll never really understand the parameters of your climate.

For cold-folk, this is of UTMOST importance.

Yes definitely! It’s nice we get a heavy blanket of snow here too. It helps insulate and protect those plants through the harsh winter. I’m just happy to realize that there are some neat trees I can grow that will survive winter!

Absolutely! If your “ME” or colder.. just assume you have to protect EVERYTHING.. somewhat.

@berzerkules is in 2

Oh my. Poor guy, I thought I had limited selection of trees!

 

[HorseloverFat]

Yes definitely! It’s nice we get a heavy blanket of snow here too. It helps insulate and protect those plants through the harsh winter. I’m just happy to realize that there are some neat trees I can grow that will survive winter!

Oh my. Poor guy, I thought I had limited selection of trees!

Hehe!

Any sheds, unheated garage space?... lumber and space for coldframes... These (standard, low-solar “recycling” coldframes) will become super effective below 32.. with a declining curve starting at like -10. At these temperatures and in these conditions... airflow can become an issue... all just things to think about.

I have a cement PIT .. for old-fashioned oil-changing, or animal.. um.. “draining”.. That works GREAT.. in theory... just have to make it accessible, as last year, it froze OVER in January.. and I couldn’t get in until March! I refer to this fiasco as “ The Frost Prison of Ultimate Thirst.”...

This year, I’m Temp- “Lean-to” framing a huge corner, I have big sheets of plexiglass AND lumber 12-18’ long.. I will use THIS space to shelter west-access to My “pit” for MORE protection.. and I have a stand-alone moderate-solar-recycling coldframe unit that will exist INSIDE the “lean-to”.. for the MOST protection...

Just gotta find something that works for your situation.

 

[PA_Penjing]

For areas “Zone 5” and colder... finding out your species’ “Root Damaging Temperatures” is FAR more useful than hardiness zones.

Good point back atcha. My limited research shows 14 degrees F or -10 C about the point where tree roots tap out. Being in containers the roots become the limiting factor. Even in my zone 6 winters, a zone 2 spruce will need a little love when temps dip into the teens.

 

[Leo in N E Illinois]

@ViridianTanuki
19 yrs is a great age to begin bonsai. I started when I was about 14, and I am now 66 yrs. For various reasons, I've started over a number of times. Tree longest in my care currently is only about 15 years in my care. My record was keeping a pomegranate healthy and growing for some 42 years, then I forgot it when we had a cold snap. They don't like hard freezes to 10 F (about -23 C.). Anyway, my backyard has long been my proving ground for winter hardiness.

Your biggest issue will be to learn how to winter trees that are hardy in your temperature zone. I have some disagreement with the published "root hardiness" table in Mike Hagadorn's books. His published temps do not agree with my experience. (that is likely the source @HorseloverFat was referring to in his comments). But I have not done controlled experiments, so I am not going to call out specifics.

With material that is successful as landscape trees and shrubs or that are native to your area, key for winter hardiness is to use the element trees in the wild use. CONTACT WITH THE EARTH. The ground is heated by heat from the center of the earth seeping outwards. Local municipal build code departments will have standards for how deep water supply lines must be buried. This is a foot or so below the average frost depth for your area. In my municipality water lines are required to be roughly 5 feet below grade, about 1.6 meters. Below that depth the soil is usually above freezing even in an unusually cold winter. Cold frames where the earth is excavated to some depth, take advantage of the heat from the ground to provide enough heat to prevent roots from being killed.

I'm in zone 5b, for trees native to zones colder, like zone 4, for these species, like my spruces, Jack pines, crabapples, and others, I simply set the pots on the ground for the winter. I throw a little mulch over them, no deeper than the tops of the pots and forget them for the winter.

With more tender zone 4 to zone 6a trees, I will dig the pots in against the side of the house, and mulch deep enough to cover the pots, maybe the trunks a little too, but key will be wind breaks and winter shade. Sun scald on those clear sunny days where the air is well below freezing, but the sun is bright and warm, sun scald can be a problem with maples and other "forest" trees. Wintering them in a shaded spot helps with this.

Constructing a cold frame, but using plywood or other opaque material will help keep trees cold for the entire winter. You want to avoid freeze-thaw cycling which is a major problem with a glazed cold frame. Most temperate winter hardy trees have no problem with being in the dark for the winter. An opaque cold frame (technically a root cellar) will help with allowing the trees to freeze once, and then stay frozen until spring. Sited on the north side of a building, in the shade you should be able to avoid issues with trees coming out of dormancy before it is safe to put them outside.

SO any species native to your area or north of you, and higher in elevation than you is a good choice for bonsai.

 

[HorseloverFat]

@ViridianTanuki
19 yrs is a great age to begin bonsai. I started when I was about 14, and I am now 66 yrs. For various reasons, I've started over a number of times. Tree longest in my care currently is only about 15 years in my care. My record was keeping a pomegranate healthy and growing for some 42 years, then I forgot it when we had a cold snap. They don't like hard freezes to 10 F (about -23 C.). Anyway, my backyard has long been my proving ground for winter hardiness.

Your biggest issue will be to learn how to winter trees that are hardy in your temperature zone. I have some disagreement with the published "root hardiness" table in Mike Hagadorn's books. His published temps do not agree with my experience. (that is likely the source @HorseloverFat was referring to in his comments). But I have not done controlled experiments, so I am not going to call out specifics.

With material that is successful as landscape trees and shrubs or that are native to your area, key for winter hardiness is to use the element trees in the wild use. CONTACT WITH THE EARTH. The ground is heated by heat from the center of the earth seeping outwards. Local municipal build code departments will have standards for how deep water supply lines must be buried. This is a foot or so below the average frost depth for your area. In my municipality water lines are required to be roughly 5 feet below grade, about 1.6 meters. Below that depth the soil is usually above freezing even in an unusually cold winter. Cold frames where the earth is excavated to some depth, take advantage of the heat from the ground to provide enough heat to prevent roots from being killed.

I'm in zone 5b, for trees native to zones colder, like zone 4, for these species, like my spruces, Jack pines, crabapples, and others, I simply set the pots on the ground for the winter. I throw a little mulch over them, no deeper than the tops of the pots and forget them for the winter.

With more tender zone 4 to zone 6a trees, I will dig the pots in against the side of the house, and mulch deep enough to cover the pots, maybe the trunks a little too, but key will be wind breaks and winter shade. Sun scald on those clear sunny days where the air is well below freezing, but the sun is bright and warm, sun scald can be a problem with maples and other "forest" trees. Wintering them in a shaded spot helps with this.

Constructing a cold frame, but using plywood or other opaque material will help keep trees cold for the entire winter. You want to avoid freeze-thaw cycling which is a major problem with a glazed cold frame. Most temperate winter hardy trees have no problem with being in the dark for the winter. An opaque cold frame (technically a root cellar) will help with allowing the trees to freeze once, and then stay frozen until spring. Sited on the north side of a building, in the shade you should be able to avoid issues with trees coming out of dormancy before it is safe to put them outside.

SO any species native to your area or north of you, and higher in elevation than you is a good choice for bonsai.

Agreed! The published data in THAT book are referred to as “Root Kill Temps”..

But larger databases and archives of similar studies exist.. under “Root Tissue Damaging temperatures” and sometimes have damage in terms of gradation.. which is pretty neat.

While “Bonsai Heresy” opened my eyes to this “angle” pf consideration, my studies took me further.

Because I remember one of those entries listed WITHIN the book.. that I had direct CONTRARY experience with.. I cannot recall the species, however.

Op... listen to Leo.. he’s “the man”!

 

[berzerkules]

Absolutely! If your “ME” or colder.. just assume you have to protect EVERYTHING.. somewhat.

@berzerkules is in 2

I had big plans to make some shelters for all my trees then I remembered I've had a potted larch my son started for a school project when he was in kindergarten. He's now 16 and the larch is fine, I never did any winter protection on that tree, the only damage it ever took during the winter was a moose chomped the top off one year.

Since it's my first winter with a bunch of sticks in pots I decide to just wing it and figure out how far I could push them trees. I grouped them together, packed soil around and in between every pot, threw a bunch of leaves over it all, left them out in the open and let them get snowed on. I don't have fabulous material and everything is local, if they die I'll know I need to provide better protection next winter. I'll learn what works through trial and error. Once I figure out what works on local trees I'll start pushing my limits on non native species and provide better protection.

 

[Forsoothe!]

OP can do kusamano with winter wheat!