Outdoor Growing in Alberta with a Cold Frame

[KB1]

Hi,
I'm growing two strains of cannabis (Northern Lights and CBD Elixer, both are regular seeds and photoperiod) outdoors in a cold frame in southern Alberta, and am looking for advice/tips for outdoor growing. This is my first time growing outdoors and using a cold frame.

Its a large cold frame (4' high, 8' long and 3' deep) with glass on both ends, top and south facing side). I'm hoping it will work well, but it is showing warm daytime temperatures already. For example, its 25C outside right now and 32C in the cold frame. Its not unusual to have daytime temps upwards of 35C during parts of July and August and last week we had a few nights where the nighttime temps dropped to 7 to 9C. I'm wondering if I have to worry much about the plants having heat or cold stress (e.g., if I keep the plants watered well, what temps can the plants tolerate without having to take action?).

Part of the reasoning for constructing the cold frame was to extend the growing season. I'm hoping to keep the plants outside until we harvest them (hopefully in late October). I'm planning on using a compost pile and pumping water under the compost and into a couple of barrels to heat the inside of the cold frame. We can have frost as early as late August but often not until mid-Sept and we can have a few snow events in September and October but the snow generally doesn't stick around for good until November or December. Despite some cold temps, we also generally have few weeks of day time temps upwards of 20+C in October and most nights the nighttime temps in October stay above freezing.

I am planning on using a max-min thermometer to monitor temps and I'll keep the plants in pots so if I have to I can move them during extended cold spells, but moving the plants inside is hopefully a last resort.

If anyone has experience growing cannabis in a cold frame in a similar climate and can share some growing advice, it would be appreciated. Thanks in advance.

 

[chemistry]

Stick some pics up of your cold frame and plants.

 

[KB1]

Thanks,

Photos are below. Plants were started on June 6 and are about one month old at time of photo. They were started late but are growing well. The cold frame was just recently built. Plants were started in the house and have been outside for about 5-6 days. They were just transplanted yesterday from 4" pots into bigger pots.

Yesterday the daytime ambient temp got to 29C and it got as high as 44C in the cold frame with leaving the doors at the back open. Last night the ambient temperature dropped to 12C. Today ambient temp is already 25C and its 42C on the cold frame. The plants seem to be handling the hot temps well so far despite being transplanted yesterday. After they were transplanted, they were left outside of the cold frame until the temperatures dropped to 27C in the coldframe.

First photo - two plants in foreground are CBD Elixir
Second photo - all three plants are Northern Lights
Third photo - close-up of Northern Lights
Fourth photo - close up of CBD Elixir
Fifth and sixth photos - south side of cold frame.

 

[Oldchucky]

53 at night isn’t too bad. Why don’t you just grow outside of the cold frame until you really need it. Looks like it’s going to get pretty cramped in there.

 

[KB1]

Thanks.
Growing outside the cold frame is an option but we get a fair amount of wind here that seems to effect the plants. We aren't home 24/7 during the day so the cold frame is also insurance against hail and we seem to see some hail most years. Our peacocks also seem to have a preference for some plants in my wife's garden and until I know whether they will go after these plants, I prefer to play it safe.
I think I'll be okay for space, my seeds were regular seeds. If close to half of the plants are male, once I remove them space is less likely to be an issue.

 

[Oldchucky]

Right on! Keep us posted. This is interesting. Oilers or flames? Lol.

 

[KB1]

It damn sure ain't the Oilers, but its also been kinda tough being a Flames fan for the last while.

 

[Oldchucky]

Count yourself lucky! Sharks fan, 30+ years with nothing to show for it except exasperation and frustration! take it easy man!

 

[Oldchucky]

I remember when Lanny, the stash, got his cup! A great moment! And I don’t think Jerome ever got one, but I might be wrong. But he sure as hell deserved one! Later!

 

[Trash_2002]

Thanks,

Photos are below. Plants were started on June 6 and are about one month old at time of photo. They were started late but are growing well. The cold frame was just recently built. Plants were started in the house and have been outside for about 5-6 days. They were just transplanted yesterday from 4" pots into bigger pots.

Yesterday the daytime ambient temp got to 29C and it got as high as 44C in the cold frame with leaving the doors at the back open. Last night the ambient temperature dropped to 12C. Today ambient temp is already 25C and its 42C on the cold frame. The plants seem to be handling the hot temps well so far despite being transplanted yesterday. After they were transplanted, they were left outside of the cold frame until the temperatures dropped to 27C in the coldframe.

First photo - two plants in foreground are CBD Elixir
Second photo - all three plants are Northern Lights
Third photo - close-up of Northern Lights
Fourth photo - close up of CBD Elixir
Fifth and sixth photos - south side of cold frame.

If you have some budget to spend buy a small green house with special agriculture film, buy one with a good height ~2.5m so you can do a intake/extraction system near the roof for the hot days and control better those hot temps, when winter arrives you could stop the ventilation system.

I mean you have the land, I would spend and do a proper small green house, that could.be used for vegetables too and etc, your wife may like the idea tho ;-)

 

[chemistry]

Build your self a tall fruit cage, that would dissipate the rain and hail, and keep the peacocks at bay.