Yield Per Square Foot

cberg · February 21, 2018, 9:55pm

Hi Everyone

I’ve seen a few posts about yield, and I know most people are probably tired of talking about it…but I haven’t seen a good poll on yield per sq ft.

If you measure using yield/sqft can you please tell me what you get from your best and worst strains? on average?

Average Yield in g/ sq ft

0-28 g/ sq ft
28.1 - 50 g/sq ft
50.1 - 60 g/ sq ft
60.1 - 70 g/ sq ft
70+ g/sq ft

0 voters

If you use another metric to measure yield, can you please explain what you use and why?

I find the industry is lacking in standard metrics for cultivators, and I just want to get a feel for what the professional growers on here use.

Thanks!

Jordan · February 22, 2018, 6:13pm

I see GPW quite a bit (Grams Per Watt) for indoor but that seems like a bunk metric to me. Emphasizing that grams/final weight are directly proportional to wattage when the reality is there are a tremendous amount of factors that can affect that growth and outcome. For example, I pulled about 3/4 pound dry weight out of a 330W Tasty LED COB light in an area maybe 2 ft by 4 ft. Big chunky buds (these are autoflowers, home grown (little heavy on the Grow More nutes, whoooops .))

Just my two cents

NextLightSupport · February 22, 2018, 6:38pm

I don’t think grams/watt is a completely bunk metric. Energy usage is a huge long-term cost factor, and over time the most overhead-conscious producers will be able to price most of their competitors out of the market. The importance of gpw depends on where you are and how much you’re paying for power.
Grams per square foot has similar limitations. In NYC or SF it would probably be a reasonable focus, while in Flint no so much. Payroll can be the biggest expense of all. I wonder if anyone is tracking grams per man-hour…

Jordan · February 22, 2018, 6:39pm

I love this. I’m stealing this.

cberg · February 22, 2018, 7:43pm

Thank you all for your input.

I personally believe gram per watt to be a “bunk” measurement. It doesn’t take anything into account except for the exact light you are using. Heck, you can use two different brand HPS lamps in the same ballast and get different result. When looking at energy consumption, g per kWh is much more useful IMO. It takes into account how long your lights (or other electrical draws) are actually on. You get charged by kWh as well…so now you have part of your cost per gram already figured out.

But for overall efficiency of your grow it is not very useful. The thing I like about g/sq ft is that you can pretty easily tie in your g/kWh to that metric. Your square footage will never change(unless you intend for it to change), but your electricity usage, man hours, fertilizer, etc can change from crop to crop or year to year.

So if you know how much you produced per sq ft you know how you are doing compared to other harvests using a metric that didn’t change. Then you can go back and say “what DID change to change my yields?” and focus on that metric/s.

I actually think tracking g/ man hour is important. Labor and utilities are often competing for top spot in the cost of a grow. If your team is producing 100 g/man hour and last year you were producing 200…well maybe you need to assess what changes you made in labor and why.

The real metric I want to look at in the end is cost/g ($/g). But most people either cannot or will not share this information. A heck of a lot of accounting goes into figuring this out.

Anyway. Glad to have some conversation going around this. Thank you again.

cberg · February 22, 2018, 7:46pm

Those are some stocky flowers!

Jordan · February 22, 2018, 7:49pm

Do you think it would be possible to create a calculator, something that takes into account some of these variables you’re talking about that would give us a better idea of yield/cost? Maybe there’s a way to incorporate a few different metrics to get a better overall picture, you know? Not picture perfect, but a generally agreed upon “we can all see the sailboat in the 3D stereogram” kind of picture.

Jordan · February 22, 2018, 7:50pm

I love COB lights! I like growing low and to the ground too (I LST everything, I have bondage issues I guess haha!)

cberg · February 22, 2018, 7:56pm

This should be possible for smaller grows. What makes it tough is when you start depreciating capital costs over time.

For instance, on a home grow scale - how much of the cost of your tent or carbon filter do you associate to each round of growing? Your carbon filter might last for 6 months and so you can apply a third of the cost for each 8 week bloom cycle. But your tent might last for 10 years…do you spread the cost out over that 10 years, or negate it and pretend it wasn’t part of your cost? An accountant would spread large capital costs over a given period of time which may or may not be completely accurate. (there are other reasons for this that are even more important from an accounting perspective)

Of course the most costly things (electricity, man hours, water, fertilizer, co2) are more easily measured per grow cycle. But if you have a perpetual harvest that will make things a little more complicated!

You can start to see why many growers do not want to start thinking this way.

Jordan · February 22, 2018, 7:57pm

What’s the solution there do you think?

cberg · February 22, 2018, 8:02pm

Look at your overall cost and yield on a larger timeframe. If you harvest everything on the same schedule (8 weeks lets say) you can assume an 8 week cycle of perpetual harvest would be the same as a single harvest in the same space.

As an example…
If you have space for 80 plants you could…

harvest all 80 at once
plant 40 and 4 weeks later plant another 40
plant 10 each week for 8 weeks.

Either way, if you keep the same pattern up for perpetual harvest, you end up harvesting the same amount of plants out of the same space over the 8 week period. So you can cost everything on an 8 week basis. Or even better just cost for a whole year. But that doesn’t help if you are trying to determine the efficiency of a new operation.

Please know, I don’t like using plant count as a metric, but it works well for this example.

WestPac · February 22, 2018, 8:49pm

A calculator certainly could be created (it’s just something I do for fun sometimes). I’m not too familiar with the e2e processes, costs, and other factors involved in growing. Off-hand, yield per square foot is a possible partial factor. That is, if the square foot is something that really isn’t being paid for directly for the purposes of growing, then it probably shouldn’t be included as an ongoing cost. However, on land or interiors that are leased, for example, the cost of each square foot would be relevant to such a calculation. A good place to look for similar calculations is restaurants where they want to fit into a limited space the most customers possible. Peak and slow periods are often averaged out.

The “partial” part of a yield per square foot metric is that it is missing time. For example, per day, per week, etc. This would let us know how fast the turn-over production rate is. A production (of anything) that takes two weeks per square foot would be half as much as one week per square foot. Again, restaurants are good examples as they try to move diners along and allow a table to open up for other customers.

Operational costs, such as electricity for lighting, are not normally included in such calculations but can be since it seems special lighting is required. Water costs and nutes could also be included. Again - normally such costs are bunched into “operational costs” but can be used in a per-yield calculation. Work hours should be included, but only for large enough operations where hours/yield would be a factor one would want to control. For example, one person spending a few hours each day taking care of only a few plants would not produce a useful hours/yield calculation.

Generally, I like to bundle operational costs into a monthly calculation. From there, a daily or even hourly average can be calculated. If we view the planting area as part of an operational expense as well, we can calculate the yield per square foot per day/week/month. The only remaining factor would be labor, which can be calculated either at an hourly rate or as a monthly operational cost as well. I did this recently for our warehouse facility to calculate exactly what we need to charge in order to sustain sufficient revenue to keep the doors open and make a profit.

WestPac · February 22, 2018, 9:02pm

@cberg

I agree with you regarding the 10-year tent example: Such long-term purchases should be just thrown in with depreciating capital costs. The carbon filter, probably not.

In any calculator I’ve created, I just add a margin (say 10%-20% or whatever seems appropriate) for “overhead” costs. This might also include bringing in a consultant for some unexpected occasion. Another margin is added for profit. If one margin is high or low, it takes or gives to the other margin. Both margins added together rarely allow the calculated TCO (Total Cost of Ownership) to fall below the actual costs.

Lazyman · February 23, 2018, 6:53am

GPW is shorthand for Jorge Cervantes’ “grams per watt per 30 days of flowering.” Most people just forget to mention the time portion.

It’s still the most accurate metric I’ve seen (when applied properly) and the standard is .5 grams per watt per 30 days. Since the timeframe is usually 60 days, we end up with the more common 1 gram per watt gold standard.

Not factoring in the time taken breaks the metric, indeed. If someone takes 11 weeks to flower and another achieves the same yields in 8, the 8 is the clear winner.

Jordan · February 23, 2018, 7:03pm

The 30 days definitely adds an element to it. The timeframes you mention (30 to 60 days,) is that in reference to flowering from clone only? Does GPW per 30 days of flowering not factor in veg time, whether from clone, seed, or watts used for mother plant? If not, why not?

cberg · February 23, 2018, 8:23pm

It really does all tie together for final cost.

If discussing in terms of grams per energy consumed…I prefer g/kWh because it actually takes into account the time the lights were on. GPW using a 30 day cycle can differ drastically if your lights were on for 12 hours a day or 8. This is more practical when applied to veg…some run their lights for 24 hours and others for 16.

Plus I can communicate with the electric company, lighting manufacturer, and accountant all using kWh.

AmericanWeedwolf · February 24, 2018, 9:56pm

We harvested just over 17,000 lbs of bucked flower from our 90,000 sq ft licensed canopy space this year, for a yield of about 85g/sq ft licensed canopy area. It should be noted that this includes full crops of both autoflowers and photoperiodic strains. The photos yielded about 55g/sq ft while the autos yielded right around 30g/sq ft. Autos tested 16%-20% THC while photos tested 23%-29% THC. Several strains pass so well for indoor grown bud, we are marketing them as such.

For the record, we didn’t plant them together in the same growing area, nor did we exceed our licensed canopy area.

@NextLightSupport to answer your question, it took just under 1,500 man hours to do all the work, for a productivity rate of about 11.5 lbs per man-hour or 87 grams per man-minute

Growernick · February 24, 2018, 11:31pm

I use the tried and true industry-standard GPW when speaking to growers or other “industry people”, but it would make sense to incorporate the g/kWh metric (even though different power companies in various municipalities charge vastly different rates) into how we define the cost of production for our product. I like to account for the total overhead that goes into production, but this can vary from grow facility depending on inputs. My rubric is “total production cost per pound” when I’m accounting for cultivation success in my facility.

david1 · February 25, 2018, 4:53am

Cost analysis has never been one of my strengths, but as it relates to cannabis production it has come up in conversations with a couple of old friends.

I speak regularly with Jorge about my progress or sometimes the lack of it on the extraction efficacy trials I am conducting using a new French technology. The subject of his visits to cultivation facilities always comes up. He knows that cultivation is of great interest to me. We have never discussed grams per watt or grams per watt per 30 days of flowering. It is always cost per gram. That encompasses everything and he feels professional cultivators should know to the penny what something costs to produce. He really likes it when he asks a grower and he gets an answer. Unfortunately, all to often the grower has no idea.

The second friend this has come up with is retired and spends time analyzing potential investments in publicly traded cannabis companies. He brought up Canopy Growth as a company he has purchased stock in. He is happy he did so long before Constellation Brands paid C$245 million for a 9.9% stake. What he likes is their honest unvarnished reports. I glaze over when I look at such things, but I found this synopsis which lists the cost per gram to the penny (or at least to a Canadian penny):

Record quarterly revenue of $21.7 million highest ever reported in Canadian cannabis sector driven by strong domestic and international sales

Record Germany quarterly sales of $1 million, all from domestic Canadian production

Year-over-year registered patient growth of 138% and revenue growth of 123%

Weighted average cost per gram1 to point of harvest decreased 18% sequentially quarter over quarter to $0.59 per gram, sixth consecutive quarter below $1 per gram; weighted average cost per gram before shipping and fulfillment decreased 18% sequentially quarter over quarter to $1.03 per gram

Only cannabis company to secure multi-year supply agreements with four provincial entities; multi-year commitments from Canopy totaling up to 25,000 kilograms per year

Secured four retail license allocations in Newfoundland and Labrador, locations represent first announced privately owned and operated legal cannabis retail locations in Canada.

Raised $245 million in landmark deal with Fortune 500 company Constellation Brands and subsequent $201 millionbought deal financing including the first co-led by a major bank, BMO Capital Markets

International production licenses announced in Denmark and Jamaica (provisional), bringing number of global licensed facilities to 102

Approximately $400 million cash on hand to fund domestic and global expansion

suehiko · February 26, 2018, 5:51pm

I’m sorry. Coming in a bit late to the conversation, and it isn’t immediately apparent to me.

You’re 90,000 sq ft is outdoor?