Buying weed is overrated. Growing weed is underrated.
If you've followed along on this Hobby Grow journey, you've no doubt heard this rallying cry.
They say growing weed saves you money, right? How much money?
Well, that's hard to say.
In today's example, a small hobby grow could save you thousands of dollars per year.
Like everything else in cannabis, you can grow cannabis successfully a million different ways, with a huge range in costs.
It all comes down to your goals:
Do you want an easy, automated approach to growing?
Where are you growing: indoor, greenhouse, outdoor?
Are you willing to hand water every plant?
Will you be in the garden every day?
I had an awesome call with a team on the northeast that's selling one of the most advanced hydro systems for tent growers I've seen, and they all but guarantee 10+ lbs per year from a 4x4 setup. Which is amazing. But it doesn't come at a budget price tag.
The more work you're willing to do yourself, the cheaper your grow can be, generally speaking.
With that said, all of these wishy-washy "it depends"-type answers can feel like a cop-out.
And with each new grower asking me a similar question, it felt like the proper time to do a deep dive on how the costs of growing compare to the costs of buying weed, and how much money you can actually save.
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Before we dive in, a few notes on housekeeping:
I ran this math by a few other growers before prepping for today's newsletter. In most cases, it checks out, but there are some assumptions made.
Clones are not included for 2 reasons: HUGE variance as to how long you veg for, and, if you are running a single tent, you do not have a dedicated mom or cloning/propagation space. Running from seed accounts for this variance, and avoids reliance on a clone source.
Autos mentioned are estimated at 12 weeks (84 days). This accounts for variance and advancements in Auto breeding that have resulted in faster finishing (70-80 day) varieties.
This math includes the costs of getting started and supplies for future cycles, as well as the power and water use for your first (and successive) cycles. For KwH/Wattage ratings for equipment, MAX wattage is used.
The rates for energy and water usages are US National Averages: $0.148/KwH and $0.42/gal.
The assumptions are in place to eliminate as many variables in the comparison. I understand that there are exceptions and cheaper (or more expensive) ways to do this, as well as huge variance in yield. Some things will not be as generalizable, like consumption rate (if you smoke more or less, that will affect the math).
Ok, let's dive in...
DEEP DIVE: How much money does a Hobby Grow save you if you smoke 1 oz a week?
For this deep dive, we will use the following parameters:
You are buying/consuming an ounce per week (3 pounds per year)
You spend $100-300 per ounce, for ~$150 on average ($7800 per year)
You will be growing 2 plants from seed in a 2x4x6' grow tent.
To Do This Math In 10 Steps, Calculate:
Cost of Initial Setup
Power Load of Setup
KwH of "always on" equipment like fans and controllers
KwH of "On/Off" equipment (Lights cycle/are not always on)
Cost of "Always On" and "On/Off" and Water for an entire cycle
Cost of First Cycle (Initial Setup + Always On + On/Off)
Cost of Successive Cycle Supplies
How Many Cycles/Year
Cost of One Year of Growing (First Cycle + X Successive Cycles)
Compare to Annual Spend if Buying
And, spoiler, the results are:
Buying 3 lbs/year: $7800
Annual Cost of Growing in a 2x4x6 setup: $1,830.24 - $2,116.23.
Annual Savings = $1,783.77-$5,969.76
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So let's work through these steps to show you how I got there (and how you can do this math on your own).
And if you really want to geek out, I'll link my raw notes spreadsheet at the end for you to check out what happens behind the scenes for newsletters like these.
Step 1. Cost of Initial Setup
We're growing in a 2x4x6 setup, so I went with the all-in-one AC Infinity package for ease.
Then, we need food and microbials, so I went with the simple, tested solutions we use in the GrowHort:
Food: GrowDots from Real Growers - Single application soil amendment
Microbials: Terragrow from BioSafe Systems - All-around awesome microbial supplement
Note: Real Growers also has a microbial product called Recharge, which has a lower cost of entry (small packets vs 5lb tub) but an overall higher cost per gram. So, depending on how long you'll be doing this, you could drop that price in the calculations a bit. As I said, always exceptions.
We also need seeds and soil.
Again, using the soil we use in the GrowHort (and what I use in my personal grow), Roots 707; it averages $30-40 for a bag.
For seeds, a good market average is ~$100. While you won't be popping the entire pack for your grow of 2 plants, most seeds are not available in 2-packs.
So, all in, our setup cost comes out to $946.
Moving on.
Step 2. Power Load of Setup
Because we are using a pre-built grow setup with all of the electronics needed, we can easily dive into AC Infinity's tech specs to pull the wattage for each piece of the setup:
Inline Fan - 61W
Clip Fan - 8W
Controller - 1W
LED Light - 200W
Our total power load is 270 watts (or 0.27 KwH), but we can't just multiply that by our energy cost, because a big portion of that (the light), doesn't run continuously.
Which brings us to Steps 3 & 4.
Step 3. KwH of "always on" equipment like fans and controllers
Everything but the light will remain on the entire cycle.
Total Watts = 70
Convert Watts to KwH by dividing by 1000.
Total KwH = 0.07
Always On:
Photos - 15 Weeks - 0.07 Kw * 24 hours * 7 days * 15 weeks = 176.4
Autos - 12 Weeks - 0.07 Kw * 24 hours * 7 days * 15 weeks = 141.12
Step 4. KwH of "On/Off" equipment (Lights cycle/are not always on)
Our light will cycle on and off. The timing will depend on whether you are running photos or autos.
PHOTOS:
Light (veg - 18 Hours, 6 Weeks) = 0.2Kw * 18 hours * 7 days * 6 weeks = 151.20
Light (flower - 12 Hours, 9 Weeks) = 0.2Kw * 12 hours * 7 days * 9 weeks = 151.20
AUTOS:
Light (AUTO - 20 Hours, 12 Weeks) = 200W * 20 hours * 7 days * 12 weeks = 336.00
Total:
Photos - 302.40
Autos - 336.00
Step 5. Cost of "Always On" and "On/Off" and Water for an entire cycle
Multiply the results from Step 3 and Step 4 by energy cost ($0.148/KwH).
Energy Cost:
Photos:
Always On: 176.4 * $0.148 = $26.1072
On/Off: 302.40 * $0.148 = $44.755
Autos:
Always On: 141.12 * $0.148 = $20.88576
On/Off: 336 * $0.148 = $49.728
Water Cost:
To calculate this, I used the total mL from a single autoflower plant over 12 weeks, doubled it (we're growing 2 plants) and converted to gallons, resulting in 35.16 gallons per cycle.
To get a rough estimate of water needed for a photo period, I divided that by 12 weeks, and then multipled by 16 weeks, resulting in 46.88 gallons.
Our cost of water is $0.42/gal.
Which makes our Water Costs:
Photos: $19.69 per cycle
Autos: $14.77 per cycle
Step 6. Cost of First Cycle (Initial Setup + Always On + On/Off)
Add up your costs:
Photos Total: $1016.86
Autos Total: $1016.61
Now, this will be your most expensive cycle, because you won't have to re-buy things like the tent, fans, and light every time you pop seeds.
Step 7. Cost of Successive Cycle Supplies
For each cycle that year after the first, you are only re-buying consumable supplies.
Items like:
GrowDots
Seeds
Soil
This assumes you're reusing your pots (growing container) and that your 5lb tub of TerraGrow will last you for the year.
Total cost: $156
If you didn't use all of your seeds, you could drop the cost of this by $100, or simply plan to buy a new pack every time, and build up a back stock for you to dip into when you find something you like or a time when you can't afford seeds.
Step 8. How Many Cycles/Year
Remember our timelines:
Photos - 15 Weeks
Autos - 12 Weeks
Which gives you roughly 3x Photo Cycles or 4x Auto Cycles per year.
Step 9. Cost of One Year of Growing (First Cycle + X Successive Cycles)
Putting it all together, let's total up our costs:
Growing 3lbs/year (AUTOS) - $2,116.23
Growing 3lbs/year (PHOTOS) - $1,830.24
Step 10. Compare to Annual Spend if Buying
Now, if you recall, we were buying an ounce of weed every week for ~$150/ounce, to the tune of $7,800 per year.
Compare that to the total growing costs in Step 9.
The savings speak for themselves.
Now, let's poke some holes in this math.
Say, for example, you still had to buy weed during the year (either because you needed weed during your first cycle before harvest, or because you had some cycles that yielded super low).
Let's say you ended up buying half as much as you normally would in a year, but you still bought ~1.5 pounds at $150/ounce.
Still saving $1783.77 - $2069.76.
Ok, but what if you're a light smoker, and you only smoke a half ounce a week?
So, rather than 3 pounds, you smoke 1.5 total per year, to the tune of $3,900.
Assuming the grow costs you the same (nothing changes on that end just because you smoke less):
Still saving $1783.77 - $2069.76.
Ok, but what if I'm a light smoker AND I had to buy weed?
Admittedly, this is where it's can be a tad more expensive to grow.
If you're a light smoker whose grow is not producing enough and you still have to buy half your weed, you're going to spend a little bit more than you would just buying all of it.
Photos save you $119.76.
Autos cost you $166.23.
Now, there's plenty of reasons to justify that $166.23 for autos (or save $119.76 per year growing photos)—from quality, selection, safety, and the benefits of a hobby—but if you are looking for the straight answer: this situation is the only one listed where it would technically be cheaper to just buy all of your weed for the year.
In short:
A 2x4x6 Hobby Grow could cost you $166.23 more per year if you're a light smoker who still buys weed.
But, if your grow covers your needs, a 2x4x6' hobby grow could save you up to $5,969.76 per year
As promised: Raw Notes Link