Ask a Master Gardener: Growing Marijuana
Have you heard the news? Marijuana/cannabis became legal in Minnesota on August 1, 2023. It only took about 15 days for me to get my first Master Gardener question about it, so I did some digging into this psychedelic plant. Full disclosure: I have never actually grown it myself, so my information was gleaned from the internet. Reader, I googled this for you and found a dizzying array of blog posts, YouTube videos and news articles. Here is my attempt to distill it all into something… edible.
Question:
How hard is it to grow marijuana? Are there any regulations around it if you’re just growing it for personal use?
Answer:
First, let’s explore regulations, since those are unique to Minnesota. The full list of regulations around growing and consuming cannabis in the gopher state can be found on a new website, cannabis.mn.gov. The state says:
- Up to eight cannabis plants, with no more than four being mature, flowering plants may be grown at a single residence as long as it is at the primary residence of someone 21 or older.
- Plants must be in an enclosed, locked space that is not open for public view.
So what this means is that, practically speaking, if you’re starting plants from seed you would start no more than four at a time, so that after you harvest the first four, you’ll have four more almost ready to flower and then you can start four more plants from seed, and so on. This is if you’d want a continuous supply.
For complete regulations around how much you can possess, and where you can legally consume it, please consult the state’s full list of regulations.
I personally think the enclosed, locked space is the trickiest part about the regulations—there goes my idea of just throwing some seeds in with my zinnias next summer. You’d pretty much have to either grow your plants indoors under grow lights, or create a beefed-up fence with a lock, and place it somewhere out of view on your property. No front-yard weed gardens for you! Well, not this kind anyway.
So what’s involved in growing cannabis? What do the plants even look like?
For starters, think of marijuana plants’ needs as similar to vegetables like tomatoes—they require rich, fertile, loamy soil, plenty of sun and regular water. They are not perennial here in the north, so you must buy or save seeds each year and protect them from frost. They like some airflow, but not too much. If grown in containers, each mature plant will need a large one—at least 3-5 gallons, depending on your particular cultivar.
Marijuana takes a long time to grow. During their vegetative state, the plants like warm weather—at least 75-80 degrees. However, when they start flowering (forming “buds”) they like it a little cooler. Temperature will be easier to regulate if they are grown indoors.
If you choose to grow indoors, you will need a good grow light system and a fan. There are a lot of tutorials on the internet for different types of systems, from basic to advanced.
When the plants flower, you will also need to determine whether they are male or female, and cull any plants that are male. When the female plant’s flowers are fertilized, they produce less THC. There are tons of websites that describe the different parts of the flower, what role they play, and when it’s time to harvest. Here’s a helpful visual (source):
This is another tick in the box in favor of growing your plants indoors, since you won’t have to worry about any bees accidentally pollinating your buds. When it’s harvest time, plants must be dried before storing to prevent mold.
What do you think? Are you going to try growing your own stash? Now that I’ve done the research, I’m not so sure. If you have grown it, do you have any tips? Please share in the comments!
Remember, anytime you have gardening questions, you can Ask a Master Gardener online or call the Yard & Garden Line at (612) 301-7590. Most of us are still pretty new to the idea of growing marijuana, so be patient with us!
Other helpful resources:
The Master Gardener Volunteer program
Jennifer Rensenbrink is a University of Minnesota Extension Master Gardener for Hennepin County and regular contributor to Northern Gardener® magazine. She grows native plants, vegetables and fruit in her south Minneapolis yard. You can follow her gardening adventures on Instagram.
hello,
you can quite easily grow autoflowering cannabis outdoors in the twin cities. it only gets about three feet high in a 3-5 gallon pot. you can even start the seeds outdoors when it is safe to plant tomatoes. it needs a lot of direct sun. challenges are bud rot from caterpillars and mold from rain. a quick flowering version will finish by early august, or, if you aren’t trying to harvest it, it has a wonderful ornamental effect well into fall.
in my neighborhood, you also have to worry about wild males pollinating it, so if you can harvest it by late july, you can avoid that.
Do you need to use R O water?
Does the law address plants growing wild in rural areas (ditch weed)?
Hi Ariel! The law says you may:
• Possess or transport up to 2 ounces of cannabis flower in a public place.
• Possess up to 2 pounds of cannabis flower in a person’s private residence.
(Those are copied and pasted from cannabis.mn.gov.)
If you’re talking about spotting some ditch weed and harvesting it, I don’t see anything on the website about whether that’s legal or not, so it may very well be a gray area. If it’s on someone’s property, that person is responsible for it growing illegally. If it’s on public land, I suppose it’s fair game? Again, a gray area.
If it’s growing wild, the timing would have to be absolutely perfect to harvest the flowers, which are the part of the plant that contains the THC. It seems unlikely (or extremely lucky I guess).
I did see some marijuana growing in a state park a few years ago, and had a good laugh about it. It did not have any flowers.
I did a fair bit of research and continue to on indoor growing. Im sure you could grow it outdoors here in MN but you’d have to mind it a bit more I think and have good timing for planting since the grow cycle is quite long. I decided to try it indoors from seed with a couple plants and have had good success thus far. My plants are just switching to week one of flower, after 9 weeks of veg. I got them to about 4′ high before switching light cycle to trigger flowering. I am using feminized seeds and not auto flower. They love attention, and need a lot of water and food/fertilizing and PH is quite important to monitor. I set up an air system on my tent that intakes under the plant canopy and exhausts outside, I think it is important to note the smell that these plants produce is strong. If you don’t use a tent indoors your whole house will smell like Cannabis. Even with venting it outside I could smell the vented air on opposite sides of the house so I know my neighbors could smell it. This was just in veg stage, smell gets much stronger at flower stage. So I added charcoal air filters to my exhaust system and the smell about went away, we will see if the flower stage overpowers the charcoal.
So my girls friend and I are of age and want to know how many plants we can grow in our house? We are both over 21 years old. The law stats that adults over 21 can have 8 plants 4 flowering plants and 4 juvenile plants. How many plants can we have together under the same roof?
8 plants total per residance doesnt matter how many ppl in the house want to grow cant have no more than 8
Cannabis is not as complex as people make it out to be. Good light, good soul, good airflow. Outside in MN has been a challenge for me, but inside it is fairly simple. I absolutely love the whole process!
Indoors Its easy & doesnt take long(3-4months). My 4th grow is about 3 weeks until harvest & my 5th grow is about 3 weeks old.
I was hoping to get a 6th started & completed in the 1st year but, dont think I’ll be able to before my 1yr anniversary of starting growing June 21,2023.
Itll be close this year but next year getting at least 6 done for sure goal is 8?
Pot grows great in MN outdoors. You do want to start your seeds indoors about the same time you start your tomato seeds and they can be brought outside or even planted right in your garden the same time you plant your tomatoes so beginning of June is usually good.
The only issue I’ve ever had is people stealing it before I could harvest and that was using seeds from Mexican brick weed so with all the different varieties available a person could grow indica dominant hybrid with a shorter flowering time.
Can I use FFOF With Schultz potting mix plus
Mixed together and start my seedling in a solo cup
Then gradually increase the pot size or
Should I go from Solo Cup – 3Gallon Bucket-5 gallon bucket
Also will FFOF (fox farm ocean forest) burn my
Plants
So gradually increase pot size or should I
Germinate-seed into solo cup, mixed-soil, then to 5 gallon bucket
IM A NEW GROWER BESIDES GROWING ONE CBD PLANT WITH JUST WATER AND SOIL AND SUN
Typically you want to germinate your seeds in a seed starting mix because the seed already contains enough nutrients to keep it alive until it grows it’s first set of true leaves. Schultz makes a seed starting mix and it’s available at Walmart. Make sure you poke some holes in the bottom of the cup for drainage. Mix up the FFOF and Schultz potting mix plus you have and put that in the bottom 2/3 of the cup. In a clean container put the amount of seed starting mix you will need to fill the remaining 1/3 of the cup and slowly add small amounts of water while throughly mixing with your hands until it is all MOIST not soggy. Fill that into your cup and plant your seed 1/2″ deep. Put it in a warm place and cover with plastic to maintain the moisture. The seed should sprout within a few days. Yes I would recommend increasing container size gradually so solo cup to something double that size to eventually a 5 gallon container so transplanting multiple times. With the FFOF and Shultz potting plus you probably won’t need to add fertilizer to your water for at least 3-4 weeks if not longer. My last bit of advice would be stay away from the marijuana growing forums, they are full of people who don’t understand basic horticulture and will only confuse you and tons of ridiculously bad information. A friend, family member, neighbor who grows beautiful vegetable and flower gardens is a MUCH better source of information. Good luck, and happy growing!
Since MN is new to the end of cannabis prohibition, the following is just some general info regarding cannabis cultivation. Not that I’m an expert by any means. I just like to grow pot and have been at it for over 50 years.
There are two main evolutionary branches of the cannabis species: indica and sativa. Indica is a more compact plant of the two. Indica is native to the middle east and more extremely arid environment. Sativa grows everywhere else and the THC content can vary from 0% to 30% or more (depending on genetics). I’ve grown sativa to 12′ or more and indica less than two feet. Hybrids of the two can be anything in between. Sativa plants can produce massive buds. Indica buds are generally smaller and tighter. I start plants indoors under a well balanced spectrum of high-intensity light, I use LED. The initial day/night cycle is 20/4 then stepping down to 12 light when the plants reaches 5 nodes. This will initiate flowering. To delay flowering and keep sativa plants shorter, pinch terminal buds once to make the plants split. This messes with the hormones from the terminal buds.
You’ve been growing cannabis for over 50 years?!?! Show me your ways oh Jedi Master! If I only had that knowledge…what I would do.
I’m in South Africa ??. I’m willing to plant my own but I don’t know where to get seeds because our stores and farmers aren’t allowed to sell seeds
I am growing for the first time with the help of a major seed breeders direction, I am in the second week of flower and all of the plants are really healthy, I would encourage others to grow also but make sure you are following the direction of a professional or whoever made the seeds. Some seeds are light sensitive and will herme if given too much light, light leaks, etc. there are forums that can advise you on the proper techniques for different seeds. Good luck
Has anyone grown Bruce Banner outside in Mn?
I have a high tolerance and need as much thc and cbd as I can get.
I need it for pain,stress( from pain), and sleep.
I grew an indica/sativa hybrid from afghan region outside this year so, of course I battled with leaf mildew.
I need one adapted to our humid summers.
Is there any regulations on how far you need to be from your neighbors from your grow sight
I live in South Carolina and am interested in growing my own to get past the %0.3 restrictions. How can I go about this?
As usual, the enclosed, industrial type locked fencing is a huge give away to industries in kapitalist MN. The first step in “legalization” was industrial “medical,” lotions. then gummies, now what business gets a license. Etc. Etc. Etc. Growing indoors requires potting soil, containers, Excel energy for growing, Etc. Etc. Etc. Bullshit. This is a rank weed growing all over. Prior to legalization it has been America’s biggest cash crop. Money money.
We have numerous cultivated and plants all over our neighborhood which are FAR more deadly than marijuana. Datura, deadly nightshade, etc. No one thrown in jail and nowhere near the warnings.
From 8 plants, one usually gets about 2 good females. Not much for eating, the healthiest way to partake. Precisely so one will need to buy from the seller…..
Hints on growth are cute, since it grows itself. Plenty of info out there. A problem in MN is the hemp borer. It will destroy mature buds rapidly. Quick action is needed.
Decriminalization is good and should have been done decades ago. Otherwise we have moneyed concerns cooking up a shit sandwich in our government.
As usual, hobbyist, personal-use growers hanmve already used visual shielding and security to prevent theft, or vandalism by ignorant anti pot folks.
No. Not advocating pot use. Just tired of all the insanity over a sacred and well known plant.
I got some seeds from trimming my clones last year. I planted the seeds and they’re growing and they’re almost 5 ft tall now but there’s no buds yet. I planted early but I’m afraid I’m growing hemp and not indica
Whoever said only four mature plants must not have any experience growing cannabis outdoors in MN. Standard photoperiod-responsive sativa strains like mine take 150 days to mature in northern MN if started on May 1. You can’t grow them in the winter unless you want to fund MPL’s execs’ retirement funds. Plus they grow very tall, which doesn’t work well in a house. And no, I do not want autoflowers. Too short, low yield, and the price per seed is outrageous.
And what is a mature plant? A few pistils emerging or a full-blown cola dripping with resin? I’ve asked the marijuana regulators and got no answer that made sense.
I have been growing outdoors cannabis plants for at least six years. I have gotten very familiar with spotting male plants and removing them immediately. This year was no different but when one plant that appeared female got taller and started to bud it was apparently pegged with seed pods. All of the growth in every bud looks pegged with seeds. The main stem still looks female. So my question is how can this be and I feel automatically compelled to destroy the plant. I just want to know why this plant is like this ?
Hi all question if you put one plant in a pot lay it down divide one stem in the dark. Will that one stand grow.
hi Are the light spectra in greenhouse LEDs different for growing marijuana?
There’s only one place that actually teaches you how to ‘grow weed easy’!
My favorite method to germinate cannabis seeds:
– Soak seeds up to 24 hours first in plain water, especially for thick or hard seeds
– Plant the seed right in the soil, one knuckle deep. Press a little dirt on top to hold it in place.
– Keep it warm and moist. (SUPER IMPORTANT). Don’t let your seed get cold or dry. Don’t touch it after it gets planted.
– Seeds pop up with cute little round leaves in a few days
– Follow a seedling watering schedule like this one from Grow Weed Easy:
How to Water Your Cannabis Seedlings: The First 30 Days & Beyond
For seedlings in 3-gallon or 5-gallon fabric pots.
Day 1 – Give 2 cups (500ml) water per plant (at this point, your cannabis seedlings should have their leaves completely open and be in a 3-gallon or 5-gallon pot under the grow light)
Day 3 – Give 2 cups (500ml) water per plant
Day 6 – Give 2 cups (500ml) water per plant
Day 8 – Give 3 cups (750ml) water per plant (every 3 days after this)
Day 11 – Give 3 cups (750ml) water per plant
Day 14 – Give 4 cups (1 liter) water per plant
Day 17 – Give 4 cups (1 liter) water per plant
Day 20 – Give 5 cups (1.25 liter) water per plant
Day 23 – Give 6 cups (1.5 liter) water per plant
Day 26 – Give 6 cups (1.5 liter) water per plant
Day 29 – Give 8 cups or 1/2 gallon (2 liter) water per plant
At this point, start watering like this…
(1+ Months) Cannabis Watering Schedule
– Wait until top inch of soil is dry (for coco, wait until top is mostly dry)
– Water until you get 10-20% runoff out the bottom
– Remove runoff (test the pH if needed) and start over
Source: Grow Weed Easy
Hope it helps someone. Once you get past germination you’ve got actually plants that are going to make weed for you. Spread the knowledge!