I have long considered putting in a cooling unit in my cold storage facility to keep things cold and dormant during freak spring weather that tends to warm up my facility. I keep cold weather natives such as larch, cedars and junipers mostly. In researching I have found that it is vastly cheaper to set up and cheaper to run, to have a cooling unit that can only chill down to 37 degrees or so. My question is whether 37 degrees would be sufficient to hold plants in dormancy?
Temperature required to hold dormancy--is 37 degrees enough?
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0soyoung
Imperial Masterpiece
Yes, according to all the scholarly papers I've read.
The problem, I believe, is if the cold dormancy requirement has been met and the temp goes above 40+F for hours/days, the engine has started and chilling again will only slow down the rate of emerging from dormancy - it will not go dormant again until it has completed the whole seasonal progression.
On the other hand, if the dormancy hours have not been met, little excursions above 40+F buds won't break / candles won't push --> this is how the dormancy requirement has come to be known, AFIK.
The problem, I believe, is if the cold dormancy requirement has been met and the temp goes above 40+F for hours/days, the engine has started and chilling again will only slow down the rate of emerging from dormancy - it will not go dormant again until it has completed the whole seasonal progression.
On the other hand, if the dormancy hours have not been met, little excursions above 40+F buds won't break / candles won't push --> this is how the dormancy requirement has come to be known, AFIK.
wireme
Masterpiece
Coolbot and ac unit? Is that what you're looking at?
Just curious, I may need to build a small walk-in cooler this summer, 37 is perfect for me.
Don't know about dormancy requirements.
Just curious, I may need to build a small walk-in cooler this summer, 37 is perfect for me.
Don't know about dormancy requirements.
Yup-http://storeitcold.com/
Anthony
Imperial Masterpiece
We set the fridge to vegetable crisper cold and hold for 2 months.
A ginkgo is our coldest patient.
Check for watering every two weeks.
1980 to today practice.
Good Day
Anthony
A ginkgo is our coldest patient.
Check for watering every two weeks.
1980 to today practice.
Good Day
Anthony
Cypress187
Masterpiece
2,78 degrees Celsius.
bonhe
Masterpiece
Besides the temperature, the number of sunlight hours to which the tree receives daily also affects to the dormancy.
Bonhe
Bonhe
DougB
Chumono
Contact Arthur Joura at the NC Arboretum. He stores many of the Arboretum's bonsai collection in a cold unit during the winter. Has done so for several winters so has a wealth of experience.
I forgot about this--I will try to get with him on this--Thanks!
JudyB
Queen of the Nuts
I like this idea, but wonder if the application is built for summer use, to keep things cool in summer. I don't know how a regular air conditioner would work in wintertime with temps getting way lower than 37? Don't know enough about it. I would love to know more.
Littlejoe919
Shohin
A split system heat pump (while more expensive) could accomplish this. The thermostat could be set in such a way that if could keep it within several degrees regardless of outside conditions. A heat pump can heat or cool depending on what's needed at the time.
TXyamadori
Seedling
You should be fine. I'm in South Texas and our lows are usually around that temperature most of the winter. My trees just started to bud out this week. I have mostly maple, elm, beech and crabapple.
miker
Chumono
Yes, it is.
I tried to message him via IBC but to no avail--do you know how to contact him?
GrimLore
Bonsai Nut alumnus... we miss you
Thanks Grimmy!--I just got your message too. I will compose my questions and then connect with him. I have been researching whether a Coolbot will work cooling my facility--I am going to have to contact the company because the square footage of the area is out of the spectrum of applicable examples given on their WS. I might have to get a used refrigeration unit in order for it to work.
GrimLore
Bonsai Nut alumnus... we miss you
Could be you just need to run duct work off the AC unit for better distribution. Either way dropping in duct lower then the ceiling will help any application a lot.
Grimmy
Leo in N E Illinois
The Professor
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Cheap alternative - a blueberry grower I know chills fruit from the field to 34 F using a big window airconditioner. He simple wired a new thermostat into a standard window air conditioner. He is able to get a 20 x 15 x 10 ft room down to 34 F in July in Michigan. Uses a air condition with a rating for 3 rooms. All off the shelf part. I'll try to find info on the Thermostat he installed.
I just texted with Arthur. He says the freezer is maintained just above freezing but below 40.
rockm
Spuds Moyogi
FWIW, this can be dependent on species. Rule of thumb is to maintain a root zone temperature of BELOW 40 F to maintain dormancy in most species. I would think that 40 is a bit too high for some stuff. I've got amur maples for instance that are pushing buds with temps consistently in the low 30s here. Sustained at 40, they would leaf out in a week or so.
The bonsai nursery where I overwinter my live oak maintains their cold greenhouse at 35 F after letting it fall into the high 20s in December for a week or so.
The bonsai nursery where I overwinter my live oak maintains their cold greenhouse at 35 F after letting it fall into the high 20s in December for a week or so.
