This year I purchased some trees that for me were on the expensive side.
I run a heater in a shed for some trees, use a cold frame for natives.
But I am running out of room in these locations.
What are your thoughts on overwintering in the house in a unheated room with the windows open and even a window fan if needed to keep things between 30-40 degrees Fahrenheit?
I assume it is not different then a unheated garage but I want to make sure I am not missing something.
Also do you guys recommend complete darkness or normal daylight if it is not direct sun?
I understand the danger of the freeze thaw situation that occurs in direct sunlight due to radiant heat
( gutters dripping on a 20 degree day because the sun is out)
but I am wondering if normal daylight is better then complete darkness.
Any thoughts or suggestions would be greatly appreciated
I would go with as normal daylight as possible, if you can keep it about 30-40 I dont see why this wouldn’t work. Keep an eye on the humidity or lack there of typically
my standard indoor cold area is similar to what you are describing. it is an insulated room with the ability to bring outside air in to keep the temperature around 40 F. winters here are generally under 40 F so this works. doesn’t work everywhere. with lots of trees, humidity is not an issue. with a few trees it can be. you need to watch them for humidity and possibly add a humidifier to the area. invest in a temp/humidity monitor and watch that it stays above 30%. I use LED lighting in the ceiling but this tends to heat the room up a bit. if you have natural light you could go without adding light. if you augment light, be careful how close you get the lights to the trees. depending on your situation and your trees, they may need watering every week or two. need to figure that out. too wet or too dry is not great. also the space may deserve some consideration. possibly trays under them. my area has an epoxy floor with a drain so watering is not an issue but it will be inside your house.
I live in northern Vermont. Outdoor winter temps are typically in low 20’s/teens with a week or two below zero. From mid-Nov to early April I store 10 of my trees in a regulated greenhouse with temps between 30 and 40 degrees Fahrenheit.
The balance of my collection (about 40 trees and seedlings) I store in my unheated garage, (temps fluctuate between 25-35 degrees) under the following setup: all are on racks; no supplemental heat source provided. Midsize and larger shohin trees have their pots wrapped in bubble wrap to keep roots slightly warmer; cold herdy trees are not wrapped; smaller shohin, mame and seedlings are put in white tubs with mulch packed around them up to the lip of the pot to keep the roots warmer. I check on them weekly and water periodically maybe once every other week… and increase frequency as Spring arrives and trees wake up. See photos.
Garage has two windows and low light. Trees are located on the non-window side of the garage. Have used this concept for at least 10 years. Lost a total of 2 seedlings and one tree during that time.
The key is to prevent the roots from freezing. Happy to answer any questions.
FYI . When asking questions if this nature . You should include your usda cold hardiness zone for mist accurate info . I live usda zone 4 near Ottawa Ontario Canada . Zone 4 is about as cold as it gets in continental USA . ( about the same as northern Michigan. I overwinter zone 5 and native zone 4 trees . In a unattached non heated garage with no light . First allow the trees to freeze on a bench then store . Some of the smaller root ball trees I bury . Up to the top of the pot . In mulch . In a larger box . But I do not have super final mame . Or sohin. ( note Ryan has talked that cold hardiness is about root ball size ) I allow my trees to freeze once then only bring them out when they will unfreeze and stay that way . Key to frozen trees . Is no drying wind . Which is deadly . ( hence the garage ) no wind full dormant . No need of moisture . Some light might. E beneficial . But difficult without un freezing trees . Conifers loose some foliage colour . And buds on decid are delayed . But once in the spring light they catch up very quickly
. One week . Many many . Nursery trees and bare root seedlings are overwintered frozen in no light commercially . It’s a go to . I am colder than you are . And that’s a factor . Just giving what I know . Unfrozen root ball . You need to walk a line . If light and heat to not wake up trees . Note most will tell you you need some light . And as a rule of thumb . A tree in a pot is one zone more sensitive than a tree in the ground. Like I said zone 4 and this works for zone 5 conifers . I’m going to try something . On the attic staircase . To a un heated attic . Where sone heat will bleed from the house for JM . This winter hope this helps . There are no fast rules . It’s what you can make work in your area
I live in the mid west zone 5 open plains where we may have 1 -3 weeks below zero. I constructed a bench with a removabe base thats filled with rubber mulch my colorado blue spruce, mugo pines an eastern white pine, stay out all winter healed in once we start getting temps of 25 at night consistently. My maples and elms also stay out there healed in until temps get to that same temp. Up until i heal the trees in I just set them on the ground at night if its going to get to freezing.
Once the night time temps get to be below 25 i will move the maples, elms and dawn redwood into a non-insulated room that i have a rack set up with lights on a timer that is set to turn on and off with the outside sunrise and sunset timing changed to match roughly every 2 weeks. Windows are opened and closed to try and keep the temp between 30 an 40 degrees as best as i can. Also i run some small fans to circulate air and keep it from being stagnant.
When spring begins to arrive the process is the reverse for re-acclimation to the outside. Also the fans help to simulate the wind so that when they do go back out its not like they are getting hit with air after having none. I use light because it is best to try and simulate the outdoors as much as possible. I knowbof very few places on earth where winter = no light. This has proven to be the best method i have tried with the highest success. I have been doing bonsai for as long as Ryan we are the same age and grew up in the same state and both spent time with Harold Sasaki in Colorado. I just missed the going to Japan part of my journey because even though I have family there my choices took me on a longer and windier road to be here learning from somone i probably met in passing long ago. Ryan is right bonsai is a lot of work, and if you want it to work to the best of your ability you have to put it in. The inside picture is before i hooked up the lights last year.
The variables I would consider are the species you’re growing and the size of the pot.
You can’t really make a generalized statement.
Some trees really need cold dormancy and others are very sensitive to roots freezing but it doesn’t sound like that’s going to happen.
Depending on what the temperature is in your area, people have done lots of creative things like digging a hole in the ground to even temperature and covering plants with mulch or dried leaves.
Unless it gets really the trees covered maybe all you need.
It’s nice to be able to put them away and forget, but sometimes we also need to check the weather forecast.
I’m in San Francisco and we don’t even get frost here repaired
By the same token I can’t get certain fruit trees to flower and we don’t get much fall color to speak of.
In regards to light, I think some light may be helpful, but I think I would vote for protecting trees from wind as being more important
