No one freak out by the brutal cold that will be here in a few days

[Groucher]

I keep my Bonsai (Maples, `Japanese Larch, Satsuma Azaleas, Crabb Apple, Hawthorn) in a Cold Greenhouse from Early November until approx March/April adjusting for different weather. (We have had some very hot months in September and October) Temperatures often reach -5 and as long as you protect the roots by checking daily and only keeping them Damp! not soaking wet they should be ok. Adjustments have to be made depending on your local weather conditions. I haven't lost any trees in the past 15 years. I live in the South East of England.

 

[RJG2]

was that I failed to water prior to the cold.

This is what I'm most worried about for mine this year. We've had very little snow and long stretches of coldish sunny weather.

For me, "coldish" = 20-30F

 

[IzzyG]

It’s the first winter for me with a self designed greenhouse and it’s definitely kept me more cautious than before. Instead of a traditional heater, I went with 2 head mini split system to heat and cool when needed. I didn’t have too much of a worry of keeping it warm enough but more so not letting it swing too rapidly when it’s 10F outside but potentially 70F inside the greenhouse(so I can’t open the doors up). So far it’s been pleasantly simple when coupled with the exhaust fans. We did get a couple of freak 60F days but inside it still kept in the low 50s when it got that hot. Otherwise its been able to average just below 40F most of the time even when it got to low single digits here the last few days. One factor that I did not account for however, is how variable the temperature is depending on the height of the probe. A shoulder high thermostat can easily be 15F higher than a probe on the ground so fans had to run at a higher speed than I initially thought.

 

[Japonicus]

Kentucky weather is a Rollercoaster… I can't remember the last time snow has stayed in the ground more than a couple days honestly.

Precisely why us in such climates, have to ignore the posts that snow is your friend and helps
to insulate the roots and foliage and twigs and buds against damage.
For the bigger picture of the entire Winter, our trees are not insulated against the elements with snow.
Typically, our Arctic blasts are without the help of snow. Typically our drying Winter winds are not protected by snow.
It’s easy for newcomers to be mislead by the safety that snow provides in similar climates as ours.

 

[namnhi]

I keep my Bonsai (Maples, `Japanese Larch, Satsuma Azaleas, Crabb Apple, Hawthorn) in a Cold Greenhouse from Early November until approx March/April adjusting for different weather. (We have had some very hot months in September and October) Temperatures often reach -5 and as long as you protect the roots by checking daily and only keeping them Damp! not soaking wet they should be ok. Adjustments have to be made depending on your local weather conditions. I haven't lost any trees in the past 15 years. I live in the South East of England.

I believe you meant -5 Celsius and not -5 F. They are very different in this case. I should get down to around -5C in my area which is quite cold for us so most trees will be inside the garage and shed for a few days.

 

[JudyB]

It’s the first winter for me with a self designed greenhouse and it’s definitely kept me more cautious than before. Instead of a traditional heater, I went with 2 head mini split system to heat and cool when needed. I didn’t have too much of a worry of keeping it warm enough but more so not letting it swing too rapidly when it’s 10F outside but potentially 70F inside the greenhouse(so I can’t open the doors up). So far it’s been pleasantly simple when coupled with the exhaust fans. We did get a couple of freak 60F days but inside it still kept in the low 50s when it got that hot. Otherwise its been able to average just below 40F most of the time even when it got to low single digits here the last few days. One factor that I did not account for however, is how variable the temperature is depending on the height of the probe. A shoulder high thermostat can easily be 15F higher than a probe on the ground so fans had to run at a higher speed than I initially thought.

View attachment 580295

care to share this 2 head mini split system? I currently use an infrared unit pointed down from the ceiling with a rotary fan that comes on when it does to spread the warm air. It does a good job, but doesn't cool. I use a thermostatically controlled electric vent and fan combo to pull cold outside air across when it gets above 45. But on very sunny days with higher outside temps I've been tempted to go with a coolbot, but it seems like a lot to do for a few days if that's all it continues to be. So I'm interested in what you're using. Do you do humidification? I've found that it's enormously important if you're heating to keep the humidity up.

 

[Maiden69]

care to share this 2 head mini split system?

Look into MrCool, I installed a small 12000 btu unit on the studio we built on our old home. The advantage on MrCool now (I think they are the only ones that do) is that they are truly a DIY, as you will not need an AC guy to come VAC/fill the system as the units and the lines come prefilled with freon. Very effective at both cooling and heating. One thing I would add is a humidifier or a small mister system, they do tend to dry the air a little too much for a greenhouse.

 

[JudyB]

Look into MrCool, I installed a small 12000 btu unit on the studio we built on our old home. The advantage on MrCool now (I think they are the only ones that do) is that they are truly a DIY, as you will not need an AC guy to come VAC/fill the system as the units and the lines come prefilled with freon. Very effective at both cooling and heating. One thing I would add is a humidifier or a small mister system, they do tend to dry the air a little too much for a greenhouse.

Thanks! I have a really good humidifier in my current system, I would not recommend any type of air heating in a (cold) greenhouse without getting humidification as well.

 

[Zac]

Starting Monday highs in my neck of the woods is supposed to be 10-15° lows 0-5° and windy. All my outside trees have been munched in in a pit with with a wood frame around top 8inches higher then ground layer so trees roots are about 2 feet down since late November. Last week we received 8 inches of light fluffy snow so I shoveled snow into pit almost completely covering trees. It's maintained temps between 28-35° so far with lows into the teens. I'm thinking I'm going to cover with plywood for next week's really low temps. All my trees are smaller pre bonsai

 

[IzzyG]

care to share this 2 head mini split system? I currently use an infrared unit pointed down from the ceiling with a rotary fan that comes on when it does to spread the warm air. It does a good job, but doesn't cool. I use a thermostatically controlled electric vent and fan combo to pull cold outside air across when it gets above 45. But on very sunny days with higher outside temps I've been tempted to go with a coolbot, but it seems like a lot to do for a few days if that's all it continues to be. So I'm interested in what you're using. Do you do humidification? I've found that it's enormously important if you're heating to keep the humidity up.

I got 2 heads of Mitsubishi MSZ-EF18NAB 18,000 BTU unit paired with the Mitsubishi MXZSM36NAMHZ2 36,000 BTU. Similar to your system, it's also attached to a thermostatically controlled exhaust fan and louvers that open/close based on temperature needs.

Heat pump mini splits do not remove much moisture from heating so it's not common to have to integrate a humidifier if it's mainly heating. For cooling however, it does dry it out and I run a Global Industrial Ultrasonic Humidifier system for those times.

 

[Dav4]

I did some shoveling before work today. Love the lake effect snow we get right before most cold fronts typically push through. There was only about 2 inches on my patio, but a little goes a long way

 

[Orion_metalhead]

Ill be getting all my trees on the ground and mulched over this weekend. Ive had a few left out that its just going to be toooo cold.

 

[rockm]

I just had a crazy idea. We know that completely burying a tree in snow will protect it both from wind and from cold. Has anyone tried using a snow machine to protect trees? Apparently, you can get cheap ones that would probably have no problem covering a cluster of bonsai trees.

Amazon.com : outdoor snow machine

Yes burying completely provides a lot of protection. I was hoping the snow would stick around on the ground/trees through the deep freeze. Rain on Saturday though

 

[Gabler]

Starting Monday highs in my neck of the woods is supposed to be 10-15° lows 0-5° and windy. All my outside trees have been munched in in a pit with with a wood frame around top 8inches higher then ground layer so trees roots are about 2 feet down since late November. Last week we received 8 inches of light fluffy snow so I shoveled snow into pit almost completely covering trees. It's maintained temps between 28-35° so far with lows into the teens. I'm thinking I'm going to cover with plywood for next week's really low temps. All my trees are smaller pre bonsai

Sounds about right. Mercersburg is usually about five to ten degrees cooler than here.

 

[coachspinks]

We have another cold snap coming next week. We may see high teens one or two nights but we have already had those. The difference this week is that we will have over 80+ straight hours of below freezing temps. That is unusual for this part of Georgia.

 

[penumbra]

I just had a crazy idea. We know that completely burying a tree in snow will protect it both from wind and from cold. Has anyone tried using a snow machine to protect trees? Apparently, you can get cheap ones that would probably have no problem covering a cluster of bonsai trees.

Amazon.com : outdoor snow machine

I was thinking of this last week. I might look into it for next winter.

A real snow maker is going to cost around $400, not including the air compressor.

That is a whole lot less than I would have thought.

 

[ShadyStump]

No real storage areas for me to move any of my trees to, and we're not expected to get enough snow to pack them in safely before hitting the subzero mark. I'm thinking of moving a couple of the smaller ones on to the back porch and nestling them in between the wall of the house and the chest freezer: windbreaks on all sides, and the radiant heat from the house and freezer mechanism might be warmer than where the pots are all tucked together right now.
Thoughts?

My concern about doing this is that they'll either get too warm and risk waking them up, or I'll be sacrificing the known level of protection for something that might not work at all. All are extremely hardy species, but also very small/young.

 

[Paradox]

Never mind. It looks like these all use "snow fluid" to create "realistic snow." They aren't just a scaled-down version of the machines they use at ski resorts to make real snow.

yea and the fluid itself isnt cheap $99 for 4 gallons, I would need a 2-3 thousand dollars worth to fill my cold frame and we dont know what exactly is in that liquid that could be bad for the trees

 

[Shogun610]

Yeah but

I got 2 heads of Mitsubishi MSZ-EF18NAB 18,000 BTU unit paired with the Mitsubishi MXZSM36NAMHZ2 36,000 BTU. Similar to your system, it's also attached to a thermostatically controlled exhaust fan and louvers that open/close based on temperature needs.

Heat pump mini splits do not remove much moisture from heating so it's not common to have to integrate a humidifier if it's mainly heating. For cooling however, it does dry it out and I run a Global Industrial Ultrasonic Humidifier system for those times.

but you have natives too aren’t you concerned your temperature isn’t quite low enough for winter in the greenhouse. Do you let your unwired stuff get a freeze before putting in

 

[snowman04]

I worry about lots of stuff, why leave Bonsai out of the worry circle. I have everything on the north side of the house, mulched/snowed in, & out of the wind. I have a BC that I fancy & worry about its roots, despite it being zone four hardy. I've been considering prying it out of the mulch & crowbarring it off the tundra, and bringing it into the garage. After thinking about it I'm just going to leave outside.

View attachment 580277

I have my two BCs outside on the ground and so far, so good...