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Hey GNET, Quick question

@growopowners How many of our growers are thinking about building outdoor greenhouse in the near future?

Feel free to email me [email protected]



100%, I am.


Hey Jake.

I haven’t heard anything from the investor yet nor from Mark all week. I have told the investor I have until mid day tomorrow to get a check to you. I will speak with you in the morning.

Mike Rochon


Definitely part of our rollout plan.


I’m a grower, not an owner. But that is something we’ve been thoroughly looking into and is in the future plans.


Hey Cody, PM with more info!

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I have been doing aquaponics for years and have help friends do set up’s and always taking a new class some where. When our state goes legal this year ( I hope) this is and then expand if I can get financing for it. Mine is just small for a family of three. I have a friend we got him started and he supports and family of five and some of his kids have kids. They all live off of his grow. Recirculating water so there’s no water waste. No need for chemical’s, all organic. Best tasting food you’ll find. So cannabis should be good too and things grow faster using this type of setup.


Many State ordinances will not permit a standard greenhouse or shade house because they can be broken into with just a razor blade. So check first.
If you do proceed, check out greenhouses glazed with polycarbonate. It comes in single, double and triple thicknesses with air gaps between the sheets. This can extend your growing season immediately, cut down on shading and heating costs and allow for internal shading on rollers. Combine that with automatic venting and the structure itself will substantially pay for itself.
Poinsettias, actually a tropical plant, are grown this way for the holiday market and they have the same day length issues that Cannabis has when it comes to timing their flowering.



It’s great to be apart of this thriving and inspiring network. I need to advice on how to go forth with some calculations. We received a mandate to produce 1000kg’s of dry trimmed cannabis per annum. Are there any calculators that can assist in giving us a rough idea as to how big our commercial scale greenhouse would need to be to facilitate that? Secondly how does ones know about big the following areas in a greenhouse need to be?

  • Mother
  • Cloning
  • Vegetation
  • Flowering

Thanks in advance.


I can produce 12,000 clones in 3,000 sqft of greenhouse floor space. I don’t do this, I only need 4000 to plant about 3300 in 40,000sqft.

Flowering is going to depend on a number of things, but I am packing 1 plant per 12sqft. You will need an aisle of about 5ft in the middle for ease of movement, and some border for air flow, say 2 ft. That gives you about 2000sqft of usable space for finished plants. Somewhere around 166 plants per 3000sqft of greenhouse, if you’re going for sardines. :wink:

As for mothers and clones, I maintain mine with an initial cloning space of 400sqft and move clones to the greenhouse as needed. I can fill half a greenhouse with 400sqft of mothers and cloning. So 800sqft to fill a greenhouse with 12,000 clones should suffice. You obviously won’t need that many unless you plan to sell clones for an income boost in spring.

I think you should yield about 200lbs of bud per greenhouse with 166 packed in there. 11 of those should get you close to your 1000kg.

You could do fewer, larger plants, but my philosophy is that canopy is canopy. 4lbs off 1 plant is the same as 1lb each off of 4 plants. It doesn’t really matter how you get there. Personally, now that we are to sqft rather than plant number, more smaller plants are much easier to maintain and handle than fewer gigantic plants.


Another consideration for space is the strain. Pure sativa will be twice the height of hybrids and indicas. Sativa also tends to spread like a Xmas tree so they need wider spacing to allow light to penetrate to the lower branches.


Conventional wisdom would say so, however in my experiene of treating all plants in the same manner, like sardines, they adapt just fine and fill the space provided.

I believe the deciding factor is whether or not one is governed by plant count or square feet.


I am a square foot guy when it comes to greenhouse production math. What is my cost per square foot week is my comparison bench mark.

I use the data from the nation greenhouse growers survey. Greenhouse production today in the USA averages .23 cents per square foot week. Up from 1990 of 21 cents per square foot week.

You can tie your production metics right back to the grow with a good chart of accounts.

The guys tying salesfource and Quickbooks are going to generate the production metrics that will be the gold standard in cannabis production.

As growers we need to get back to basic on production math.

@Growernick likes the fill it tell it bursts and he has success. I am of the mind I can produce the same dry weight with fewer plants. I may be even able to have a higher dry weight per square foot week with a lower population density. There is a whole queueing methodology on production density. It also makes IPM easier.


I’m going to find out if that is true next year.

I’m going from 13 to 12 rows (my row spacing needed some binding to be legal), and from 3fr spacing to 4ft. This will be 2500 plants rather than 3300. My goal is to at the very least yield the same, but my ultimate go is 2.0lbs per plant average. I am also planning to walk my rows with a hedge trimmer around mid-July and see how topping affects yield and harvest handling. My plants were too tall this year and cumbersome to harvest.

The only problem with giving plants more space is that the rules here in Oregon cause dead space to count against your canopy. I think I did a pretty good job of maximizing canaopy by choking out every square inch of dead space. My best cultivars yielded were 1.6lbs/plant with just 12sqft of real estate (60g/sqft).


I remember a table corn verity want of the first supper sugar varieties, that was to tall for me at 5 foot 3 to harvest. I had to hire a basketball player from the local high school to help. He was 6 foot 6 and he struggled.

Dan, I would work at gram per square foot of production area. That the level of granularity I would hope to work for. This will make it easier to compare your field to greenhouse.

Tracking per plant is useful but not enough detail. I know for example that 606 packs in our operation gave us better cost product values than a 608. 36 plants vs 48 plants in a 2 square foot area at the rooting stage. We had better plants and less shrinkage for the next stage.

A hedge trimmer timed just right time will give you short fat plants. Don’t ask how I know. The solo gas hedge trimmer works well on cannabis. Easy to clean easy to keep sharp. The feds love the solo trimmer they can go all day without cleaning. :wink:

Please keep us in the loop.


I actually ascribe to the same school of thought as @ethan in that less is more with population density with your plants. IPM is much easier to control. Unfortunately I am bound by very strict state and city codes that prevent being able to exceed certain square footage restrictions, hence the plant orgies that are my rooms.

I currently grow rather large plants in 10 gal containers. I just ordered up a few larger containers to limit the total number of plants in a given area to just a few but hopefully increase the dry yield. What are your thoughts on this?


I do track grams per square foot of canopy as a whole production assessment, as well as the per plant average by cultivar. I also like to track the whole wet plant to dry usable material conversion average by cultivar and as a whole. I don’t keep track of individuals aside from what metrc makes me do (just plant wet weight at harvest and then batch weight of waste, water loss, and usable material). I also don’t worry about the outliers, which could be half a pound to 3 pounds per plant. As I am sure you are aware, every square foot of soil is different from the next. Looking at individual plant would be about as futile as trying to ammend ever square foot of my soil to perfection. This is true for me and my commercial methods, potted plants and controlled environments are a different story, in my opinion.


Yes and yes and yes and yes.

That’s the joy of both. I would never do one without the other. To factory like to just be in a greenhouse. And growing in the field needs a whole different set of skills and problems. My fields are beautiful beds of flowers. :slight_smile:



What are you using to figure out those metrics? Are you figuring that all out using spreadsheets or some fancy cost accounting at all?


Metrc requires that I weigh every single plant and seperate them by harvest batch per day. My employee and I can harvest, weigh, and hang 1 row of one cultivar (about 250 plants) per day. Then I dry it, and remove stems and most of the water leaf, which I also have to weigh and record. Then we package, weigh, and record. To close a batch you record water loss which is just wet weight minus waste minus package weight. We then pull of the that data into Excel and make pivot tables for various uses to evaluate the year versus other years.