Heat Retension at Sub-zero

[digitS']

I noticed that the inflated double wall and fan became very common about 25 years ago. It seems like a wonderful idea.

What you have going for you now, ON, is what Eliot Coleman advocates. Also seems like a wonderful idea .

Keeping plants alive even if they cannot necessarily grow during the winter-time has value . Any additional material for the sunlight to pass thru does, however, decrease light. Far enuf north, we also have important issues with angle of sunlight, cloud cover, and short winter days . . .

Personally, I like what you've got now even if it doesn't amount to too much more than storage system thru the most serious weeks of winter. I hope you will keep us informed of the results of the additional steps you will take.

When this snow melts I will take a picture of the bok choy that is still alive outdoors. Yes, there are a number of plants that are still alive but one would have to be pretty desperate to eat them ! Actually, when the weather warms - many of those plants will die rather than come back to life :/ . . . those that don't die will immediately and feebly, bloom.

Anyway, bok choy is fairly tough and, of course, there are others.

S'

 

[chris09]

ON,
I didn't think you came out of the hen house over there at BYC..

Chris

 

[Organics North]

Ya ya..
So true Chris....ouch that hurts...


S'
I hear what you are saying!
You sure are right about the dark, I am at 46 Lat and on the edge of the Lake Superior snow belt. It is often that we do not see the dismal weak sun for more than a few hours a week from November through January. Then the cold comes.. We hit about -30 in February.

So no matter how warm it is with supplemental heating still there is not enough light for active growing without artificial light. I would be happy with a greenhouse that could be active from Late Feb through early Nov.

I am very interested in this subject of heat retention... I have the pretty much the same situation as you. (The inside of my greenhouse has about the same climate as the MOON this time of year!)

My Kale has been harvestable all winter... I am happy for that! I have requests for year round kale from my customers.. So 2011 is the year of Kale for me..(100's if not a 1000 of them)..

On a side note, 3/4 season crop planning is mind boggling in a greenhouse.. I am having trouble figuring out where to put the fall/overwinter crops while the summer crops are finishing up..:/

ON

 

[digitS']

You have summer crops in there, ON?

I thought I was the only one weird enuf to do that. Okay, it is efficient not weird .

Still, my summer crop doesn't really count for much: there is basil and last year, I left a few tomato plants in the greenhouse. They got kind of HUGE! Only a couple of years ago, the greenhouse was empty from about June 1st on.

Your winter weather must be considerably colder and growing season shorter, than here. So, I suspect that you have warm-season crops in your greenhouse thru the summer.

Steve

 

[Organics North]

Yes our summers are generally and cool and sometimes short. I roll back the cover during the warmest two months of summer, but if we have a stretch of nights in the 40' I will put the cover back on.

The first and foremost function of the greenhouse is to allow me to grow and ripen tomatoes other than bla short cool season varieties..

So during summer I have tomatoes, cucumbers, squash, sweet potatoes, peppers, egg plant, watermelon using up space.

ON

 

[chris09]

Steve,
I have a book (somewhere) that is based on solar green houses and they were talking about putting 55 gallon drums that were painted black and filled with large rocks and sand on the north side of the greenhouse so that the sun would heat them up during the day and the heat from the drums would radiate of them at night. I have yet tried this but if I ever have a greenhouse with the north wall higher than 6 inches I think I might.

Oh Steve,
I checked my greenhouse and this is what I got so far today.

At 8:53 18 outside air temperature and 40 greenhouse air temperature. (with the sky clear and the sun shining strong)
At 10:07 20 outside air temperature and 75 greenhouse air temperature. (with the sky clear and the sun shining strong)

Chris

 

[wifezilla]

Hi ON! Glad to see you finally joined us over here row

 

[Organics North]

Hi ON! Glad to see you finally joined us over here row

Ya I am a little slow..

ON

 

[digitS']

. . . When this snow melts I will take a picture of the bok choy that is still alive outdoors. Yes, there are a number of plants that are still alive but one would have to be pretty desperate to eat them ! Actually, when the weather warms - many of those plants will die rather than come back to life :/ . . . those that don't die will immediately and feebly, bloom. . .

I am not quite sure why I'm showing you this now. Perhaps, it's just to show that bok choy can take -10F twice, about 6 more nights with temperatures below 0F, 2 10" snowstorms with more piled on between, and still survive:

Now, does it matter that they have survived to this moment? No, probably not -- only the plant in the lower right corner has any chance of living out its life now that the snow has melted off of it. The others will just succumb to decay as the soil warms.

I guess the point I can make is that a plastic tunnel inside a greenhouse would probably have been sufficient for these plants to have survived in robust, good health! I mean, they almost made it with no protection at all. . .

Steve

 

[lesa]

Well Steve, the other day when the snow melted for a second- I saw something still alive too- a dandelion!!
I am thinking of making some kind of roll-up curtains for my green house. Maybe out of those silver survival blankets.... we'll see.