Leafly’s outdoor cannabis grower’s calendar
Growing cannabis outdoors is easy. All you need is a nice open space that gets lots of light, a water supply, good soil, and a way to cover the plants when the weather turns.
One of the most important things to know is that cannabis is dependent on a photoperiod, meaning that it changes from the vegetative to flowering stage when days start to shorten and nights get longer. You want to time things right so your plants can maximize their exposure to light during the summer before fall sets in.
Growing and harvest times here reflect ranges of time in the Northern Hemisphere. For more growing tips on specific regions, check out this guide on different climates.
On the West Coast of North America, cannabis farmers in Northern California have a long season: They can put plants outside early and harvest later into the season because of the region’s relatively warm weather.
Washington state, on the other hand, will have a shorter time frame, as plants can’t be put outside until later in the season because there’s not enough sunlight yet. Harvest needs to be completed earlier, before cold weather descends on buds and makes them wet and moldy.
The Spring Equinox is a good reminder that it’s time to kick off the outdoor growing process and start germinating your seeds.
As the sun reaches up high in the sky, your cannabis will want to as well. Make sure all of your plants are outside by the Summer Solstice.
The weather will start to turn and the sun will begin descending in the sky as your plants fatten up with sweet, sticky buds. It might be tempting, but wait until around the Fall Equinox to start harvesting.
Everything should be cleaned up, dried, and curing well before the Winter Solstice. Now’s a good time to make your own cannabutter, topicals, or tinctures with all that trim from the harvest. Kick your feet up, relax, and hunker down for the cold, it’s been a long growing season!
Notes on phases
I can’t stress enough that the time frames on this graphic are ranges of time for the Northern Hemisphere. You’ll need to adjust them based on your specific region and local weather and climate.
Be sure to keep a grow journal to track the progress of your plants. Looking back on your notes will help you learn from mistakes and maximize the quality and quantity of your buds.
Take meticulous notes on when and how you perform each step, as well as what the weather is like. Other notes can include how much water you give plants, at what intervals, and how much nutrients you give them. Pictures will also give you a better sense of how your plants look along the way.
Figuring out which strains you want to grow, where to purchase them, where on your property you want to grow, and your local climate and weather can take some time and work. And once you order seeds, it can take a few weeks for them to arrive. Be sure to do your research early and get a head start so you aren’t scrambling at the last minute and miss the ideal time to grow.
It takes about 3-7 days to germinate a seed. A lot of growers will do this indoors because seeds are delicate and it’s easier to control the temperature and climate inside. But if you live in a warmer climate, by all means, start growing them from seed outside. You can also use a small greenhouse outside to keep them warm.
When you start growing your seeds depends partly on how big you want your plants to be for harvest. If you’re going for high yields, the earlier you grow your plants, the bigger they’ll be. But keep in mind that smaller plants are more manageable and easier to top and prune.
Move outdoors/Put in the ground
If germinating seeds and growing them indoors first, this is the time frame that you’d move your plants outside so they can get some serious sunlight. You want them to get at least 6 inches – 1 foot in height before putting them outside, so they’re big and strong enough to handle the weather.
Some old school gardeners will tell you to wait until after Mother’s Day to take them outside, and generally speaking, you want them in the ground by the Summer Solstice at the latest.
Most growers top their plants a few times (two or three) throughout the season to encourage outward development and make plants bush out. It’s a good idea to give them an initial top after the plant develops five or so nodes.
Once your plants start flowering and producing buds—generally, sometime in August—you want to stop topping your plants.
Pruning and cleaning up plants is done as-needed. You want to get rid of dead leaves and lower branches that won’t get light so the plant can use that energy for producing buds in healthier branches.
Growers can clean up their plants anywhere from 1-4 times during the season, depending on how big the crop is and how much labor is needed.
What kind of strain you have and what climate you live in will determine when to harvest your strains. Indicas typically grow stouter and bushier and there is more of a concern that their dense buds will get moldy, so they’re usually harvested on the early side of the season. Sativas are generally taller and less dense, so they usually get harvested later.
Growers in colder climates will need to finish their harvests earlier, sometimes as early as September, for fear of wet, cold weather setting in and molding out buds. Warmer climates can sometimes harvest well into November.
This post was originally published on January 15 31, 2019. It was most recently updated on May 1, 2020.
Growing cannabis outdoors is easy, but timing is important. This guide will tell you what you need to know to get the most out of your garden.
Cannabis Light Schedules: Vegetative Stage vs Flowering Stage
Cannabis plants keep getting bigger and bigger with long days, and start making buds when you give them long nights.
Cannabis is a “photoperiod” plant, which means the amount of light received each day decides when the plant starts flowering or making buds. This article explains how much light a day your photoperiod cannabis plants need to grow and start budding, so you get to a happy harvest day. What about auto-flowering strains?
Vegetative – Seedling or clone leads to Vegetative Stage –
Give 18-24 hours of light a day
Flowering – Flowering (Budding) Stage leads to Harvest –
Give 12 hours light & 12 hours dark each day
Seedling or Clone
While not technically a “stage,” all grows start with cannabis seeds or clones.
Plant your seeds or clones when you’re ready to start growing! What are clones? https://www.growweedeasy.com/cloning
Some outdoor growers start their plants indoors to give them a headstart before putting plants outside.
If you’re growing cannabis outdoors with seeds, you should wait until a few weeks after the spring equinox to put your seeds outside. In the northern hemisphere this means seeds go outside in-or-after April, In the southern hemisphere seeds go outside in-or-after October.
For growers starting with cannabis clones, generally you should wait a few weeks longer than with seeds. Cannabis clones are more prone to flowering early outdoors than seeds, so you might want to put your clones out in late Spring or early Summer. (What are clones?)
If you live in a cold climate, you must also wait until after the last frost before putting your plants outside. Freezing temps will kill cannabis plants. Strain choice is very important. Some strains flower earlier than others. For outdoor growers in cold climates, it’s important to make sure you grow a strain that is matched up with your local weather, so that plants are ready for harvest before temperatures drop.
The vegetative stage is one of the most important parts of the life of your cannabis plant.
The vegetative stage is the growing stage of the plant. When in veg, cannabis plants grow bigger and taller, growing only stems and leaves. As a grower, you are able to control the size and shape of your plants in the vegetative stage using simple training methods.
During the entire vegetative stage the plant does not produce buds at all. It only grows stems and leaves. During the vegetative stage plants tend to grow very fast, especially when conditions are right.
What keeps cannabis in the vegetative stage?
Short nights keep cannabis plants in the vegetative stage. You can keep a cannabis plant in the vegetative stage for basically forever as long as the plant continues to get short nights (shorter than 1s-12 hours, depending on the strain).
Cannabis will stay in the vegetative stage as long as the plant gets short nights (less than 11-12 hours of darkness each day)
Whether you’re growing indoors or outdoors, you must make sure your cannabis plants get at least 13 hours of light each day to stay in the vegetative stage. If your plant gets a few long nights, it may start budding before you want.
The plant can receive as much as 24 hours of light a day while in the vegetative stage. Many indoor growers provide 18-24 hours of light a day (known as 18-6 or 24-0 light schedules) during the vegetative stage to encourage faster vegetative growth.
Don’t want to worry about light schedules? For growers that don’t want to pay attention to light schedules, there are auto-flowering strains of cannabis, which will automatically go through their whole life in about 3 months no matter what light schedule is provided. For some growers, an auto-flowering strain may be more simple than a traditional (photoperiod) strain.
Most indoor growers provide 18-24 hours of light a day (known as 18-6 or 24-0 light schedules). Giving your cannabis plants more hours of light each day in the flowering stage will encourage faster growth.
Lingo: When a grower provides 18 hours of light a day and 6 hours of darkness, this is commonly known as the 18/6 light schedule. For 24 hours a day, this is referred to as the 24-0 light schedule.
As long as your plant is getting plenty of light a day, your plant will automatically stay in the vegetative stage from late spring until late summer. Every strain is a bit different.
Cannabis starts budding when plants get at least 12 hours of uninterrupted darkness each night. After plants start budding, they must continue to get long dark nights until harvest or they may revert back to the vegetative stage.
Indoors most growers put their plants on a 12-12 schedule to initiate flowering. Outdoors the plant will naturally start budding in late summer when nights are growing longer and longer as winter approaches. Just make sure plants aren’t exposed to light during their dark period!
What is 12-12 Lighting?
The indoor grower will need to artificially induce flowering/budding in plants by changing the light schedule so the plant receives only 12 hours of light a day, and 12 hours of uninterrupted darkness.
Once the plant is changed over to the flowering (12/12) light schedule, there is generally another 6 weeks-5 months (average 2.5 months) before the plant’s buds are ready for harvest.
Outdoor growers wait until their cannabis plants start naturally flowering on their own, usually after mid-summer when days start getting shorter than 12 hours.
It’s important to make sure plants aren’t exposed to light at night during their dark period, even street lights or spotlights, as this can prevent cannabis plants from flowering properly.
Growing Indoors? Not Sure When To Switch To Flowering?
So indoor growers have a choice to flower their plants whenever they want… When is the best t ime to start flowering your cannabis indoors?
The real answer is that it’s a matter of personal preference and also depends on what end result you’re looking for. There are two major considerations when choosing the right time to switch to 12/12, the age of the plant and the height of the plant:
Age: Some growers feel that a marijuana plant which has been grown from seed will not produce as many buds or have enough resin production if the plant is not given at least 60 days in the vegetative stage to mature before it’s changed over to the flowering stage. This is not true. many growers initiate flowering soon after germinating a seed in order to keep plants small and short. This is often called “12-12 from seed.” Just remember, no matter what you do, a young cannabis plant will not start flowering until it is 2-3 weeks old. Even if you put a seed on a 12-12 schedule from the beginning, it will not start properly budding for about 3 weeks. When growing with cannabis clones, age is not an issue and growers can switch directly to flowering once your clone has established roots. This is because even though a clone may be small, it’s still a ‘mature’ plant since it is made of a piece from a mature plant. Rooted clones tend to grow much faster for the first few weeks than plants grown from seed. In any case, age is not much of an issue, and you should switch your light schedule at the time that best fits your needs.
Height: A general rule is that your marijuana plant will double or triple in size during the flowering stage from the point where you first change over the light schedule to 12/12. Some plants will grow more, some will grow less, but a good rule of thumb is to change your light schedule over to flowering when your plants have reached half of their final desired height. Bending, known as “LST” or “low stress training” can be used to control colas that get too tall. Simply bend too-tall colas down and away from the center of the plant. Some growers will even slightly break or “supercrop” branches to get them to bend at a 90 degree angle. For those growing in a small space, height may be the primary concern. However, there are many techniques available to grow a short, bushy weed plant or basically train your cannabis plant to grow into any shape you want.
Here’s an example of LST to keep a plant short:
In optimal conditions if height and space is not an issue, you would probably want to vegetate your cannabis plant for 60 days or more before switching it over to flowering. This gives your plant plenty of time to grow big (so you get bigger yields), and allows new growers to dial in their grow before plants enter the sensitive flowering stage. In the vegetative stage, it is easy to recover from problems, but problems are a lot more serious in the flowering stage, where mistakes can dramatically hurt your final yields.
Giving cannabis plants more time in the vegetative stage, and taking time to train them to fit your space, will give you the best final yields. However, if space is tight, then it’s better to switch when the plant is half the final desired height, or even to just attempt to flower your cannabis plant straight from seed.
After the vegetative and flowering stage are over, it is time to harvest your plants!
What do I need to know about light cycles and flowering my marijuana plants? Plants keep getting bigger and bigger with long days, and start making buds when you give them long nights.