Building a mini-greenhouse for hardening off seedlings, force flowering

[Emeraldo]

Jorge Cervantes' book "Marijuana Outdoors" mentions using a small greenhouse, and I wanted to build one for hardening seedlings off, protecting plants in early veg from cold, and for force flowering early to identify gender. Here's how I made mine.

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• Emeraldo
• Feb 21, 2023

Using wood glue and wood screws to assemble frame

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• Emeraldo
• Feb 21, 2023

Adding cross bars for strength

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• Emeraldo
• Feb 21, 2023

Hardware in critical corners

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• Emeraldo
• Feb 21, 2023

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• Emeraldo
• Feb 21, 2023

Top beams in place

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• Emeraldo
• Feb 21, 2023

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• Emeraldo
• Feb 21, 2023

Side top beams at angle for rain runoff

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• Emeraldo
• Feb 21, 2023

Center cross beam in floor reinforced with heavy duty corners

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• Emeraldo
• Feb 21, 2023

Shim was needed when I cut angled side beam too short!

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• Emeraldo
• Feb 21, 2023

Top end

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• Emeraldo
• Feb 21, 2023

Finished frame with floor in place

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• Emeraldo
• Feb 21, 2023

Wheels for easy rolling

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• Emeraldo
• Feb 21, 2023

Synthetic sheet to create greenhouse walls

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• Emeraldo
• Feb 21, 2023

Thermometer

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• Emeraldo
• Feb 21, 2023

Cross ventilation & roof

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• Emeraldo
• Feb 21, 2023

Complete

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• Emeraldo
• Feb 21, 2023

View inside

 

[013]

Hey Emeraldo!

killer project and I hate you… cuz now I need to add it to my to do list

In all seriousness looks like a great design- simple yet very sturdy, appreciate play by play details too. I like that skin material, woven fiber for strength but clear for light penetration.

question for you… how wide is the roll of covering?? I really like that.

remember peeps no matter what your shrink sez… grow room / greenhouse envy is for real

 

[Emeraldo]

Hey there 013, thanks for chiming in.

Oyeah Freudian greenhouse envy! Let a thousand flowers bloom! Haha

Since I started growing standard/regular seeds again, I've had some stressful experiences with finding males flowering in the girls dormitory and this simply will not do. I grow late-flowering sativas, and it would be a huge advantage to get them to show sex early.

So besides giving extra warmth for seedlings and young plants, I will force flower when the time comes. In early or mid June, I will move the box into a shady spot and throw a light-proof tarp or two over the top, creating darkness before sundown, say at 5 pm and removing it before sunrise. After about two weeks, I'll know which plants are female or male and let them go back into veg.

To your question: The roll of covering is a product for winterizing, for wrapping up plants and trees to help withstand cold. It comes in a 2 meter wide format, so I had to cut it down to size before attaching.

But that brings me to the dimensions of this project, which I forgot to mention. I kept the size of this box very simple. The frame is 1 meter long, 50 cm deep. The height is 1 meter on the tall side, 80 cm on the shorter front side.

It was a good winter time off-season project. Looking forward to using it this Spring, not too far off now.

Cheers,

Emeraldo