Cold Frame in Northern MN

[fourteener]

After a winter of extremes I decided I can't leave my trees to the whims of Minnesota winter. I took the back third of my garage and converted it to storage. r-50 in the ceiling, R-30 in the walls, r-20 on the floor in the heated side.The heated side is 4x8.5 and the unheated side is 11x8.5.

I have found that using pink foam board, gorilla tape and the expanding foam insulation is a pretty solid way to make a smaller box if that's what you need. After three years my old heated cold frame was intact and doing well. The above components also came apart pretty well so I could reuse it in making this bigger version.

I am trying to accomplish two things here including shelter from the wet, wind, cold, and sun of winter. Also I'm trying to keep this thing as cold as possible for as long as possible into the spring. I really need to keep things frozen until May 1.

I wired it for an automatic fan that I might install later(as money permits!!)

Crust if you have anymore ideas after watching...I'm all ears!

My real unknown at this point is how cold will it get in this unheated side and if I need to buy a thermostat to keep it above 20 or so.

[video=youtube;ttbHHCGMgCU]https://www.youtube.com/watch?v=ttbHHCGMgCU&feature=youtu.be[/video]

 

[crust]

You gotter done! It looks great. Winter will be the trial. I suspect the smaller size will make it a bit touchier than my larger one but with your Norbilly ingenuity I am confident it will work fabulously--plus this coming winter you can pull trees out for communal Norbilly butcher sessions!

 

[fourteener]

You gotter done! It looks great. Winter will be the trial. I suspect the smaller size will make it a bit touchier than my larger one but with your Norbilly ingenuity I am confident it will work fabulously--plus this coming winter you can pull trees out for communal Norbilly butcher sessions!

Getting all my tamarack wiring done in the winter will be a bonus!! Depending on how cramped things are, I imagine I might have to keep the air moving. Is it possible for the room and trees to get too cold in this setup? Maybe the bigger question is the ideal temperature to be shooting for? Is 20 degrees too cold? Do I need to have a thermostat and milkhouse heater on hand in case it gets too cold? At this point that's my biggest concern.

 

[crust]

Getting all my tamarack wiring done in the winter will be a bonus!! Depending on how cramped things are, I imagine I might have to keep the air moving. Is it possible for the room and trees to get too cold in this setup? Maybe the bigger question is the ideal temperature to be shooting for? Is 20 degrees too cold? Do I need to have a thermostat and milkhouse heater on hand in case it gets too cold? At this point that's my biggest concern.

I have always tried to get everything nice and frozen then keep them that way. I also keep them out on the benches until they freeze and stay that way. After storage I gradually allow it to get into mid to low 20's. Most of the storage season it hoovers from there to 32. If it is a mild winter and I have to ventilate a lot I have to watch moisture levels because the soil can desiccate even when frozen--if this happens I dust them with snow, which seems to work. Anyway, I have always avoided temps below 20 sometimes I have let it dip into the low teens. I have never perceived any over protection problems--just evil spring freeze-out prairie weather when I get um out too early.

 

[wireme]

As far as leaving trees out on benches till they freeze keep in mind the roots need some time to harden off before they freeze. In the ground they have more time to prepare as it takes longer cold periods to freeze the ground. I lost almost my entire collection of cold hardy native trees to an early and extreme cold event about 5 yes ago. I found out later another bonsai grower in Calgary had the same losses that year and so did local landscape nurseries. It was probably something like a 1 in 50 year event but something to watch for for us cold climate growers .




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[JudyB]

Nice to see that you're putting the effort into making a cold storage space for your trees. Not enough people plan and do, most hope and then whine when the losses start....

 

[tmpgh]

I have a small poly house that I tried to use last winter, but it ended up keeping things too warm, and when the deep freeze came in late winter, I lost trees. Would putting this insulation material on the inside prevent that at all or should I look for a totally new solution?

 

[Jason_mazzy]

I am assuming the poly house gets hit with sun and that warms up the house. If that's the case and you live in a cold enough area you would have to vent it during the day then close the cents at night. Probably an insulated dark box would work best.

 

[tmpgh]

I guess I was wondering if I could convert the poly house to a dark house by installing insulation etc. Might be best to start a new thread on this.

 

[Dav4]

I guess I was wondering if I could convert the poly house to a dark house by installing insulation etc. Might be best to start a new thread on this.

Depending on the size of your green house, white Poly plastic sheets wrapped on the outside would work. They're opaque so minimal heat gain during the day. Most professional with hoop houses use this instead of the clear stuff to reduce heat gain and keep the plants cold and dormant.

 

[fourteener]

I have a small poly house that I tried to use last winter, but it ended up keeping things too warm, and when the deep freeze came in late winter, I lost trees. Would putting this insulation material on the inside prevent that at all or should I look for a totally new solution?

I had two versions...1. Outside: On the north side of my garage(free from sun and temp swings)I built a square with cinder blocks and used this on the inside. Plywood on top, bags of leaves on top of that.

2. Inside my garage: I made a box with 4x8 foot sheets of foam. Taped it together with gorilla tape and sealed the seams with expanding foam. I used some 1x4's on the inside to give it a little structure and a place to hang a light. Being inside my garage there was no exoskeleton around the foam as the garage was my protection. Outdoors would require plywood, blocks...something to bear the weight of the snow, wind, or children!!

This doesn't let any light in, keeps the wind and snow off of your plants. I always spray everything with a fungicide before I put things away, I also take all of the dead leaves off of deciduous material.

 

[fourteener]

I have a small poly house that I tried to use last winter, but it ended up keeping things too warm, and when the deep freeze came in late winter, I lost trees. Would putting this insulation material on the inside prevent that at all or should I look for a totally new solution?

I also think your poly house is maybe better used in the spring when you need to protect newly potted things from temps getting too low. I'm not sure what your weather is like or what kind of snow you get. For me a poly house could never insulate enough and wouldn't be rugged enough for more than 100 inches of snow.

I think you need a light free insulated structure to really do it well and avoid temperature swings. In the end our trees in a cold climate need protection from sun, cold, and wind. This last winter was too cold for too long and the trees that got burned were not totally buried in a drift of snow like the others.

Back to your original question about poly...I think the question is how will you protect your trees from the big three...sun, wind, cold?

 

[tmpgh]

Well, the structure protects from wind just fine. I was hoping that by attaching insulation to the inside of the house, against the plastic walls and roof, it would thereby be protected from wind and cold. Then, in the spring, I could pull the insulation down and use it to keep things protected from late frosts.

 

[fourteener]

Open for Business

I'm all done and ready for winter. This is the heated portion. I keep it at 36. I did decide to buy some LED's and plan on having light in there this winter. The LED's are all about not emitting (much) heat but seeing if things will be any healthier with light even while cold? I'm guessing it might take longer for them to shut down into dormancy.

Again the thermostat is a simple greenhouse thermostat. You have to use a greenhouse thermostat as all home thermostats will not go below 40. So far I'm happy with how it's holding a temperature in there. Even with some cool nights upon us, the temp hasn't changed at all.


Any advice on where to get a thermometer that records the temps or one that lets me know that information inside my house?

 

[Cadillactaste]

Sweet setup! As for thermometers...I was contemplating this on. It has an alarm that goes off when things aren't right.
http://www.littlegreenhouse.com/accessory/meters.shtml

 

[fourteener]

Here's the unheated side. I did go ahead and buy another thermostat for this room. Being new to this I want to know how cold it's going to get in here. If it gets too cold I want a thermostat on hand. It can be a backup in case the other fails. The two trash cans are how I mix my fertilizer in the summer. I will freeze water in them to act as a cold sink to keep this room frozen as long possible into the spring (think ice in your cooler!).

It feels like there is no way I am going to get my trees in this room, but it always felt that way with my outdoor storage as well. I did rebuild a smaller version of my cinder block/pink insulation box outside. I have room for overflow. I also plan on leaving several hardy things outside as I have before. Nice things get an invite to be inside!!

Now I just need a couple of fans and I'm good to go.

 

[coh]

You can get cheap, remote reading thermometers at Lowes. However, with any of them - depending on the distance and how many obstacles (walls, for example) lie between the sensor and the receiver - you might run into transmission problems. Perhaps the more expensive ones would do better in that regard, but you could start off with one of the cheaper ones and see if it does the trick. I have one in the shelter inside my barn and get spotty transmission even though the distance is only about 50 feet...but there are 2.5 walls in the way (house wall, barn wall, shelter wall).

One question, why are you going to keep the one room at 36? What kinds of trees will you be storing in there? I've been able to keep pretty much everything in my regular cold storage (27-28) except for coast redwood, camellia, and a few other sub tropical types.

Chris

 

[fourteener]

You can get cheap, remote reading thermometers at Lowes. However, with any of them - depending on the distance and how many obstacles (walls, for example) lie between the sensor and the receiver - you might run into transmission problems. Perhaps the more expensive ones would do better in that regard, but you could start off with one of the cheaper ones and see if it does the trick. I have one in the shelter inside my barn and get spotty transmission even though the distance is only about 50 feet...but there are 2.5 walls in the way (house wall, barn wall, shelter wall).

One question, why are you going to keep the one room at 36? What kinds of trees will you be storing in there? I've been able to keep pretty much everything in my regular cold storage (27-28) except for coast redwood, camellia, and a few other sub tropical types.

Chris

Good question. Last year I had two storage options, one at 36 degrees and one out in MN winter, possibly 30 below... or worse. When I made that differential I had to keep Jap Maples, boxwoods, Chinese elm, Shimpaku , JBP, JWP, Chojubai in the warmer environment. I still want to keep those species at the 36 although some of them would now do okay in the 20+ degree room. But I really do want my cold room to be frozen cold. Those trees were mostly okay out in the natural weather. I just don't want them to get colder than 20 anymore.

I still think there is a difference, but the line is much closer now than it was when some were inside and the rest were outside here in Northern MN.

 

[JudyB]

Any advice on where to get a thermometer that records the temps or one that lets me know that information inside my house?

Looks like you did a great job, and you'll be safe and snug this winter. Better than sweating it for sure. I use this setup for remote monitoring, and it has a feature, that keeps the max and min temp recorded so you can see what is going on. Then you can clear it each day for new min and max. I use three remotes, one in the actual outside world, one in the cold greenhouse, and one with a soil probe to see where the soil temps are keeping.

Mine does fine thru walls and the garage, had it for 2 years now, I like this one better than my old ones. Remember to use lithium batts. in cold areas.

http://www.amazon.com/Ambient-Weath...2273777&sr=8-2&keywords=ambient+weather+ws-10

http://www.amazon.com/Ambient-Weath..._sim_hg_3?ie=UTF8&refRID=18NZWTYMPB39VXYWCJ31

 

[fourteener]

Looks like you did a great job, and you'll be safe and snug this winter. Better than sweating it for sure. I use this setup for remote monitoring, and it has a feature, that keeps the max and min temp recorded so you can see what is going on. Then you can clear it each day for new min and max. I use three remotes, one in the actual outside world, one in the cold greenhouse, and one with a soil probe to see where the soil temps are keeping.

Mine does fine thru walls and the garage, had it for 2 years now, I like this one better than my old ones. Remember to use lithium batts. in cold areas.

http://www.amazon.com/Ambient-Weath...2273777&sr=8-2&keywords=ambient+weather+ws-10

http://www.amazon.com/Ambient-Weath..._sim_hg_3?ie=UTF8&refRID=18NZWTYMPB39VXYWCJ31

What are the soil temps that you get in the coldest part of winter? Is it warmer/cooler than air temp?