Japanese White Pine zone 4 winter

[Ryan99]

Hello,
I just found this page after days of searching for info, glad I did!
I was recently gifted a beautiful Japanese White Pine and have some questions on winter care.
I’m in southern Wisconsin and the temps are fluctuating quit a bit at the moment, 50f during the day to 20 at night. I’ve only had this for a week and for the time being I’ve been putting it outside for the sun during the day and putting into my garage at night which right now is a constant 55f or close. I have other bonsais, some for many years that do just great in the garage over winter when it’s more like a constant 45. However I’ve read this tree needs a cold/dark dormancy. I’m planning on building a box, insulating it and filling with mulch to the lowest branch and regulating temp with bulbs. Big question, does this white pine have a chance this way? I’ve also recently read about the fridge method, sounds crazy to me but makes sense.

I greatly appreciate any insight offered to keep this beauty alive and healthy.

 

[Ryan99]

X

 

[sorce]

Welcome to Crazy!

Sorce

 

[HorseloverFat]

Wow! That’s a gnarly lil’ pine..

Zone 4?? South Wisco?...

Like LaCrosse Area?

JWPs in THESE temps.. in containers,.. are pretty tender, from what I hear.

The guys at BABS put their Japanese pines in the warmest parts of their coldframes/sheds/shelters..

I’m in 5a, 23 miles east of Green Bay on the Door/Kewaunee county line... I have to protect EVERYTHING... except larches and LARGER picea Abies... so they get protected too.. might as well.

 

[HorseloverFat]

Operation: Overwinter (As coldfolk)

Learning much in my past two winters spent containerized tree/shrub gardening in, not only Zone 5a, but in the wildly chaotic transition months of Wisconsin seasonal change; I’ve decided to document THIS year’s HOPEFULLY “most successful yet” overwintering techniques and apparatuses I shall...

www.bonsainut.com

This is my approach, this time around.

 

[JudyB]

This appears to be JWP grafted onto JBP rootstock. You'll want to do winter protection for JBP, which are less cold hardy than JWP. I place mine into cold storage that stays between 30 and 40.

 

[Leo in N E Illinois]

@Ryan99 - JWP is not that different from any other conifer. Refrigerators and elaborate contraptions with light bulbs and other such gear are totally unnecessary, and quite likely to result in damage to the tree or worse. If kept below 40 F, they do not need light, but not needing light does not mean they MUST be kept in the dark. On the contrary, it is quite okay to have light. i leave mine in the back yard where they get full sun for a few hours every day, all winter. When the snow is deep, they are "in the dark" when it is a dry winter, they get full sun every day. JWP, and most temperate trees are not that complicated to get through a winter.

JWP on its own roots is fully winter hardy through zone 4. It is a high elevation pine in Japan. Wintering a JWP on its own roots is easy in most of North America, as most of North America is zone 4 or warmer. Simply set the pot on the ground, mulch the pot to the rim, and forget it for the winter. I do this in zone 5b. It works. I have a couple JWP on their own roots.

One tip, JWP on its own roots can develop root rot if your winters are exceptionally wet. JWP should be in a coarse media that breathes easily, and allows water to run. Make sure where you site it for the winter the drainage holes do not get blocked by mulch or debris blowing around. As long as the pot drains, the roots will be fine.

However, most JWP are grafted, which if the understock is less winter hardy, the hardiness is limited to that of the root stock. Judy B is spot on, most likely the JWP is on JBP root stock. I have JWP on lodgepole pine roots, and JWP on Pinus sylvestris roots. Both were acquired from landscape nurseries rather than bonsai nurseries. These two root stocks are winter hardy enough I just set them on the ground and mulch the pots a little. Both sylvestris and contorta are hardy through zone 5.

But Judy B is right, your tree most likely is on JBP, because your tree was propagated for bonsai. JBP are a zone 6 tree. Your garage, where you winter your other trees should be just fine for the JWP. JBP do fine with a 35 to 45 F winter storage. If I were you I would simply put it in your garage for the winter with your other bonsai.

 

[Ryan99]

Wow! That’s a gnarly lil’ pine..

Zone 4?? South Wisco?...

Like LaCrosse Area?

JWPs in THESE temps.. in containers,.. are pretty tender, from what I hear.

The guys at BABS put their Japanese pines in the warmest parts of their coldframes/sheds/shelters..

I’m in 5a, 23 miles east of Green Bay on the Door/Kewaunee county line... I have to protect EVERYTHING... except larches and LARGER picea Abies... so they get protected too.. might as well.

Hello,
Thank you for the info. Currently i am checking temps in my garage to see exactly how low it gets, it's hard as my garage has 2 common walls and all unites are built above them. I've also constructed a wooden box that i plan to insulate a bit and keep track of internal temps.

 

[Ryan99]

@Ryan99 - JWP is not that different from any other conifer. Refrigerators and elaborate contraptions with light bulbs and other such gear are totally unnecessary, and quite likely to result in damage to the tree or worse. If kept below 40 F, they do not need light, but not needing light does not mean they MUST be kept in the dark. On the contrary, it is quite okay to have light. i leave mine in the back yard where they get full sun for a few hours every day, all winter. When the snow is deep, they are "in the dark" when it is a dry winter, they get full sun every day. JWP, and most temperate trees are not that complicated to get through a winter.

JWP on its own roots is fully winter hardy through zone 4. It is a high elevation pine in Japan. Wintering a JWP on its own roots is easy in most of North America, as most of North America is zone 4 or warmer. Simply set the pot on the ground, mulch the pot to the rim, and forget it for the winter. I do this in zone 5b. It works. I have a couple JWP on their own roots.

One tip, JWP on its own roots can develop root rot if your winters are exceptionally wet. JWP should be in a coarse media that breathes easily, and allows water to run. Make sure where you site it for the winter the drainage holes do not get blocked by mulch or debris blowing around. As long as the pot drains, the roots will be fine.

However, most JWP are grafted, which if the understock is less winter hardy, the hardiness is limited to that of the root stock. Judy B is spot on, most likely the JWP is on JBP root stock. I have JWP on lodgepole pine roots, and JWP on Pinus sylvestris roots. Both were acquired from landscape nurseries rather than bonsai nurseries. These two root stocks are winter hardy enough I just set them on the ground and mulch the pots a little. Both sylvestris and contorta are hardy through zone 5.

But Judy B is right, your tree most likely is on JBP, because your tree was propagated for bonsai. JBP are a zone 6 tree. Your garage, where you winter your other trees should be just fine for the JWP. JBP do fine with a 35 to 45 F winter storage. If I were you I would simply put it in your garage for the winter with your other bonsai.

This is absolutely amazing intel, thank you! My garage space just stays so warm with 2 common walls and units above. For example last night temps here in Madison were low 30's and the garage temp didn't go below 60. I have constructed a fully inclosed box with removable top and currently have it sitting on my deck. I plan on filling it mulch and watching temps during the cold winter months. The tree has room to be raised inside the box if needed, i plan on keeping the humidity tray underneath the pot and just putting mulch around the pot up to first level of branches. The different roots are very interesting to me, didn't know that was a thing with these trees. This tree definitely keeping me on my toes compared to others i have had great luck with.

 

[Ryan99]

This appears to be JWP grafted onto JBP rootstock. You'll want to do winter protection for JBP, which are less cold hardy than JWP. I place mine into cold storage that stays between 30 and 40.

Thank you very much! Where is your cold storage stored? Would you say 40f is the warmest a garage could be to keep this tree healthy and happy?

 

[Ryan99]

Welcome to Crazy!

Sorce

might be an understatement, . Thanks!

 

[Potawatomi13]

Please add location to personal profile.

 

[Ryan99]

Hello,
I just found this page after days of searching for info, glad I did!
I was recently gifted a beautiful Japanese White Pine and have some questions on winter care.
I’m in southern Wisconsin and the temps are fluctuating quit a bit at the moment, 50f during the day to 20 at night. I’ve only had this for a week and for the time being I’ve been putting it outside for the sun during the day and putting into my garage at night which right now is a constant 55f or close. I have other bonsais, some for many years that do just great in the garage over winter when it’s more like a constant 45. However I’ve read this tree needs a cold/dark dormancy. I’m planning on building a box, insulating it and filling with mulch to the lowest branch and regulating temp with bulbs. Big question, does this white pine have a chance this way? I’ve also recently read about the fridge method, sounds crazy to me but makes sense.

I greatly appreciate any insight offered to keep this beauty alive and healthy.

Looks like I was wrong on my zone, I am actually in 5a.

 

[HorseloverFat]

Looks like I was wrong on my zone, I am actually in 5a.

For “broad swings” assume you LOSE an entire NUMBERED zone in containers.

For me, ALSO in 5a, I find looking up the actual “root-damaging temperatures” for certain species... assuming that the roots, in containers are coming into contact with ALMOST the same temps as the air AROUND the poT, can be more helpful than USDA zones... this IS wisconsin, after all.

 

[JudyB]

Thank you very much! Where is your cold storage stored? Would you say 40f is the warmest a garage could be to keep this tree healthy and happy?

After going dormant the temps will not want to get above 40 for any length of time. During warm sunny winter days, you may get above that temp if you open the doors. I have a dedicated building purpose built to keep the trees between 32 and 40 all winter.

 

[Ryan99]

After going dormant the temps will not want to get above 40 for any length of time. During warm sunny winter days, you may get above that temp if you open the doors. I have a dedicated building purpose built to keep the trees between 32 and 40 all winter.

I am definitely leaning towards the separate structure option. I have built a wooden box 2x2x2 and have filled the bottom with about 4 inches of mulch. I am now in the process of acquiring a heat lamp that does not produce light and monitoring the temps with a blue tooth thermometer inside the box.

 

[Ryan99]

After going dormant the temps will not want to get above 40 for any length of time. During warm sunny winter days, you may get above that temp if you open the doors. I have a dedicated building purpose built to keep the trees between 32 and 40 all winter.

Looks like I will be doing the dedicated location option as well! Just need to get the temperature regulation finalized and hope I’m all set for it’s first WI winter.

 

[Ryan99]

Hello All,
Just wanted to update everyone on the status of my JWP! Thanks again to everyone who chimed in, because of you. i'm happy to report the tree is doing great, or at least i
I've attached a couple photos of the shelter i built it for the winter months here in southern WI. Temps are still fluctuating a bit, have had many nights in the low 20's only for it to be 55F during the day. One question i do have, the box is filled with mulch up to the lowest branch, i've been checking the soil humidity about once a week currently, so far it seems about every 2 weeks it needs a bit of water. Do the same watering requirements apply during dormancy, as far as if soil is dry water it? Thanks again everyone!

 

[JudyB]

Do the same watering requirements apply during dormancy, as far as if soil is dry water it?

Yes, do not let it completely dry out. If you get snow, then it'll likely water itself as the snow melts. And if it's frozen it will not need water. Don't water it if the soil is frozen.

 

[Ryan99]

Yes, do not let it completely dry out. If you get snow, then it'll likely water itself as the snow melts. And if it's frozen it will not need water. Don't water it if the soil is frozen.

Thank you very much @JudyB !