Do you folks worry about the real feel temps when deciding to bring trees inside in the fall, or early winter?
I assume it is mainly dependent upon wind chill and my trees are behind a cinder block barrier until temps get cold enough to move things inside permanently.
Just wondering how you folks views this, or how you handle things to minimize unnecessary movement of trees as it is a lot of work.
Thanks in Northern Vermont Zone 5 A
I worry about the actual temperature, how long the temperatures will be low, and exposure to a cloudless sky. I am protecting some marginally frost hardy trees for lows of 26 to 28F (-3.3 to -2.2C) for a couple of hours overnight by covering them with floating row cover to avoid radiation loss to the sky. I have had frost on sleeping bags at 40F (4.4C) on clear nights in the desert.
The real/feel temp is a measure of how the combination of temperature and wind will cool a standard human which is producing heat. it is not really useful for things that do not produce their own heat.
Wind will have an impact on the rate of cooling of your pots to the actual temperature. Pots are fairly slow to chill due to their thermal mass in still air. Wind will speed up the process of cooling down to the actual temperature (from the outside to the inside). If this temperature is below the root kill temperature you will have issues. Putting the pots on the ground and protecting from the wind is very useful to protect from short term exposure, particularly if also protected from the sky. For example, a tree with a 25F (-3.9C) root zone temperature will probably be fine with such protection when the temperature dips to 20F (-6.7C) or even lower during quick cold snap if will warm up above freezing the next day.
A quick note is that root zone kill temperature are typically much higher than the top kill temperatures that are more readily available for our trees. Sometimes the difference is as much as 50F (28C).
Thanks for the input.
I have been ignoring the real feel information but since I saw Fridays forecast I thought I would get another opinion.
Right know they are temporarily heeled-in, in a gravel bed with a cinder block wall to protect them from the prevailing winds.
I have used my instant read meat thermometer to monitor the gravel as well as the temps inside the pots and so far all is well.
I am hoping to keep them out of the shed until late November because while I can heat the shed if needed, I can’t cool it off as well as I would like so it is more of a cold weather protection that once they are tucked in, they don’t come out until spring.
Thanks again for your time!!
this is a topic we are considering at the moment in WI/MN. I look strictly at temperature and dont worry if it is down to freezing at night and jumping up into the 40s and 50s during the day. wintering is kind of a slow dance with us. sensitive trees in first and then gradually put them all away ending with those that can handle cold like ponderosa pines. right now I studied the weather forecast every day and commiserate with others in the area as to what they have in now. considering bringing in some more trees this weekend. We up here in the northland are getting thrown by the change in our weather. cold storage isn’t cold enough yet to put trees away. agree wind is bad. started storing my trees that can be frozen inside a building to avoid the wind. didn’t even freeze last year it was so warm. had to use water to water them instead of just piling snow on them.
I too live in northern Vermont zone 5A…about 1/2 a block from Lake Champlain. Have grown bonsai here for the last 30 years. As you know unless new to Vermont, because we have valleys, mountains and lakes, temperatures can vary wildly within the zone overnight as winter approaches. That makes it difficult to accurately PREDICT nightime temperatures by simply checking the forecast.
Marty’s point about “wind chill” is spot on and supported in this article by Morten Albeck.
That said, because of the unreliability of forecasts I tend to err on the cautious side at this time of year. I have about 35 trees (mixture of conifers and deciduous, majority of which are shohin and mame), keep 10 in a greenhouse over winter, which I pay for…the other 25 are kept in my unheated garage on racks through winter…shuttled between outside during the day and the garage at night from late October to late November until they finally stay in the garage until Spring.
Because of their size, at this time of year the majority of my trees are on racks with wheels so they are easily moved inside or out. I also keep 3 stationary racks inside and outside the garage which makes the transition of the few larger trees easier.
The transition I describe takes about 5 minutes each morning and evening. I sleep better at night knowing the trees are protected. Would rather be cautious than wrong. Of course, everyone’s circumstance is unique, and you know yours best, just wanted to share what I have found works for me since we are neighbors.
Lastly, if you are new to Vermont, just wanted to suggest you look into joining the local bonsai club I’m a member of the Green Mountain Bonsai Society (GMBS). We hold meetings monthly except in the dead of winter…and usually bring in well known bonsai experts who do workshops and lectures. Reach out if you’d like more info.
Hello Neighbor,
Thank you for the information.
It is very helpful.
I am a newer member of the GMBS, life long Vermonter but new to bonsai.
I like the idea of the racks with wheels, a real time saver.
Yeah, forecasting weather in Vermont is near impossible, and the forecasts are often very inaccurate, but they do seem to be improving or perhaps my age has taught me to stick my head out the window and see for myself.
As you know this time of the year is tricky, 29 at night and sunny and 70 during the day… Hard to know exactly what to expect and what the low will really end up being.
It seems we are close to the same time frame on buttoning things up for the winter at the end of November, early December. With any luck I will be installing input and exhaust fans in the shed this weekend to help deal with the daily temp changes due to solar radiation. I have thermometers on both the North and South side of the house and have seen up to a 60 degree temp variation due to the solar radiation, that whole dripping icicles on a 20 degree day thing…
Thanks again for the input!
