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Last year we built a custom design solar greenhouse in our backyard in Central Alberta. The short grow season here can be challenging, with late frosts and large temperature swings throughout the summer. I remember a few years ago getting over 16" of snow in September.
The greenhouse is insulated on 3 sides, with the south side angled roof pitched to the suns altitude giving full light transference from February to November.
This grow is to experiment with late season growing in the greenhouse. We also have a temperature & humidity data logger, which we have been using to capture data throughout the summer, and will continue into the winter. Estimating around 12-14 weeks puts the harvest well into November, and we can certainly get loads of snow and temperatures down to -20C, so certainly climate control will be the biggest challenge. We try to gain as much heat passively through the glass, which has proven to be very effective. The main shoulder season/winter challenge is retaining heat overnight and on cloudy days. We have a bunch of thermal mass which I have built with painted cinderblocks filled with concrete and water barrels. Much of this is out of the greenhouse at the moment but will be added back in once the weather starts to cool off.
I would not be surprised if we need to add some supplemental heat on a thermostat to prevent freezing overnight, but want to minimize this as much as possible. I did install a 20A GFCI in the greenhouse this year and have a natural gas tee close by, but have not yet figured out the final heat solution for this greenhouse.
For this grow I am again using a homemade organic soil mix. We blend our soil in large batches and use it for all our container gardening, including all our peppers, tomatoes, cannabis, melons etc...
Basically we combine Compost, Coco Coir, Perlite (~30%), vermiculite, worm castings, blood meal, bone meal, epsom salts, dolomite lime.
This batch was mixed a few months ago, and I have since amended it further with some additional compost, bone meal, blood meal and some fish fertilizer which I have added over the past few weeks to help boost beneficial microbe colonies. We are using a 5 gallon fabric pot, currently it is sitting in the middle of the greenhouse, however it will move to up on the upper shelves to maximize sunlight hours and warmth overnight once the temps cool down.
Germination for me has worked great this year (100%) by soaking seeds in water for 12 hours and then planting directly into substrate. She popped up after about 72 hours, and has been growing steadily. She started in the garage grow box, along with 2 photoperiods (see other diary), on day 4 I have moved her out to the greenhouse.
Rainy days and cloudy skies have likely eased her transition to the greenhouse, she seems to be doing fine. I will likely move her over a bit so that she gets full sun days after the first sunny day. Next few days look pretty good.
I am thinking of maybe doing some HST to this lady. I know that most would say not to do such things to an autoflower, but I have seen that some had great success. Will have to wait and see how everything goes in the next couple weeks, but looking at Week 3 for maybe some FIMming.
Hi—- best to use two kinds! Alternating every other day if you have an infestation or twice a week for prevention. I use citric acid based — Dr Zymes and essential oil based —- Athena IPM—- both are fantastic! Don’t cheap on IPM. It’s expensive!✌️🏻💚🌿💨
She moved over in the greenhouse at the start of week 2 to get more late afternoon sunlight hours, I had her tucked in the side for a couple of days to acclimatize after moving her from the grow lights. Also I ordered some Dr Zymes this week. I had to go through a third party international shipping company as it is not available in canada. If you have seen my other diaries you will see this ones sister getting destroyed by spider mites, so i am looking forward to getting her inoculated a couple times before flower starts.
I was hoping she would have her third node poking out by now. she is certainly pretty leggy, likely due to the limited direct sunlight hours/transition. I will probably FIM her in 2-3 days, my indoor grow will be ready for its fist top then, and I figure why not make a day of it?!
(I love working from home)
This week the auto got FIMmed.
As mentioned last week, this girl is going to be a bit of an experiment pushing some of "rules" for autoflowers.
She seems to be responding well to the FIM, plenty of new growth. Next week we will see how many new shoots we got.
She has started flowering. A nice stretch and some hairy little flowers starting to appear.
The FiM only ended up with 2 shoots. A bit of a bummer that didnt get 4, but no big deal.
I have continued innoculating with Dr Zymes - she looks beautiful and healthy without any sign of pest damage.
Top dressed with some bone meal this week, and moved to flowering fish fertilizer.
She is popping off good! Really seeing some great bud development. Looks like i have got the other pheno compared to the first one of these girls I grew. This one has beautiful dark coloured flowers, I am really looking forward to seeing how they mature.
Plant looks super healthy! Had a good week of sunshine, a few cold nights coming. I have started to winterize the greenhouse a bit, including removing a lot of non-productive growth (Tomatoes, squash etc) and by adding in more water storage containers and bricks to increase thermal mass and stabilize temperatures. I did install a 20A GFCI there this year, so I will run some supplemental heat when needed.
She is looking beautiful! I have increased the water storage/thermal mass in the greenhouse to help buffer against the night time temperatures where it is now sometimes going below freezing.
Bud growth is a little small - as expected with lower temperatures and diminishing sunlight. That being said, the buds that are growing look fantastic. I had seen the darker phenotype in pictures and stoked that I have one of them.
Plant is super healthy.
She has survived! Unlike the cucumbers and most tomatoes. this is because when we went for our last camping trip (with snow!) we may have left the greenhouse door open for 3 days with nights below -5C.
It really hasnt seemed to phase her at all, maybe a bit more purple, and she does look beautiful. I have popped a heater in there with the thermostat as low as it goes - just to stop temperatures going below freezing.
She is starting to stank! A very sweet smell.
The days are getting shorter, and the sun is certainly losing intensity. But this next week looks good. I am really looking forward to seeing how this ends, she is super healthy, but will she get enough light in November? Time will tell.
She is beautiful!
Seeing her purple blooms and healthy green foliage sprinkled with frosting seems a solid protest to the autumn browns, greys and reds outside. A strong sweet smell wafts from our greenhouse across the yard.
The days are certainly getting shorter. She gets about 9 hours of direct sunlight but certainly the intensity is decreasing daily. I am thinking 3-4 weeks to go, but time will tell.
Decreasing nightly temperatures are in season, dipping below freezing each night. I have been steadily increasing the water storage volume in the greenhouse and have a dozen more surplus buckets headed my way soon which will certainly help to buffer indoor temperatures overnight.
For feeding, just the ocean mix and surge plus set to 6.0-6.25 pH.
Well, the snow has started to fall and the days are getting pretty short. But, she is doing well. This week the buds gained a bunch of density, with beautiful sticky frosting all over them. Still a bunch of white hairs shooting out - a couple weeks left.
Wonderful colours coming through the fan leaves now and a couple starting to yellow off a little as well as she ripens. Sweet stank and stickiness all over the flowers, which are nice and dense now. Still a few white pistils here and trichomes are still mostly clear, I am thinking it will be likely closer to 2 more weeks (14 weeks total). She is looking super healthy, no signs of rot or anything else to be too concerned about.
Peppers and tomatoes are also still going strong in the greenhouse, enjoying an unseasonably mild autumn in Alberta. Weather looks fine this upcoming week, semi-overcast but hopefully enough sun to help finish her off nicely. Temperatures should be warmer than -10C overnight, so likely around 3 to 6 C inside the greenhouse. Before the colder snap at the end of the week I will try to fill a couple gaps and maybe decommission one of the automatic vents.
She is nearly nearly nearly ready! Photos on tops of main colas look ready, but the lower buds still have a lot of clear trichromes, so I will likely give another day or so. Buds are dense, sticky, candy sweet smelling and the colours are fantastic. Beautiful purples across the leaves and with the typical yellowing of the larger fan leaves she looks like an autumn goddess. Timing is perfect and she should be dried and well cured by Christmas. She had her final dose of the humics and ocean mix at the start of the week, and has been enjoying mollassas and water since at ph 6.25, her final drink will likely be tonight.
On a sunny day it gets in mid 20s in the greenhouse, but on overcast days is still in the low teens.
A previously mentioned, this has been a great experiment as this has been our first full year using it and overall are stoked but have some improvements we are still working though. So being that this is likely the last week I will comment on the grow I will quickly ramble some thoughts.
The design of the greenhouse was to be March through November use, with the general concepts of angling glazing to capture more sun in shoulder season and well insulated to reduce energy loss overnight. All in all it has been a huge success, and optimizations have and will continue. We have been as low as -10C overnight but it is staying above freezing inside - we still have a few dozen jalapenos, sweet peppers and tomatoes. Needless to say, we are pretty stoked that the greenhouse is working as per design, and is increasing our very short Canadian growing season by likely about 4 months per year. A huge win!
There is a small electric heater in there, but it is just set to stop it dipping below freezing and rarely comes on, needless to say, even on a sunny day in November the temperature controlled extraction fan has not come on once, which is perfect. The sun is certainly losing intensity, but I also put in a 20A plug there this week (GFCI breaker and a nice weatherproof container of course), so now the window seals better overnight without the extension cord going through it.
This is the second gorilla cookies auto this year, and although the first had great growth in the summer sun it was stricken by spider mites, which thrived in the crowded and poorly ventilated space. Things are actually growing really well in this shoulder season. The more moderate temperatures and way more space inside now that we have removed much of the summer growth seems to be really helping with pest control, and the humidity has been really easy to control. We have been using Dr Zymes as well, and having a fan on a timer has certainly helped - we will be investing in a couple of bigger wall mounted circulation fans next year. We are also looking at continuing with the IPM sprays as well as continued/improved introduction of predator species.
Done.
I harvested this plant at the start of Week 14. There was bad weather coming through the weekend so not much reason to leave it in the cold without sun. She was a very stinky girl while drying. The initial dry took 6 days. She is now in mason jars and will cure.
Initial tasting was really good. It is one of those highs that you kinda dont feel much, but then all of a sudden realise you are wasted. I expect it will become a bit more sedative as it cures also.
Okay, so results. 125g wet, and 25g dry. This is obviously a bit low in general, BUT considering she was grown with minimal light intensity during November in Alberta, with snowfalls throughout flowering I think she did pretty well. The greenhouse worked great, and I am looking forward to testing a super early season grow, which I expect will do better considering improving light during flowering.
Buds are beautiful, sticky, smelly but a little airy - I assume due to the lower fall light. Very healthy plant, and significant colours, this is likely due to a combination of genetics and the cold overnight temperatures.
So, conclusion. Yes, with a wicked awesome greenhouse I can grow through the cold fall months BUT at lower yields due to lower sunlight. I could supplement with lighting in the greenhouse, but really i would just use the indoor set up at that stage.
Pagus
