Outdoor Grow Calendar For Marijuana Plants: A Complete Guide
The grow calendar is an essential aspect for rookie outdoor gardeners to master. When you’re using nature as your grow room, your cannabis crops rely on environmental conditions outside your authority. Awareness of general trends helps you achieve abundant harvests.
When should you germinate? When do you switch the nutrients from nitrogen-rich vegging solutions to phosphorus for flowering, and when are your plants harvest-ready? These are all vital questions that become much easier to answer with the help of a definite timetable.
Nature doesn’t always follow a schedule, though. The growing marijuana outdoors timeline differs from one cultivar to the next. You can still learn the general rules and apply them to your situation, becoming much more in control of the process from start to finish.
Today, we’re delivering the ultimate marijuana grow schedule for northern and southern parts of the US. We’ll go through everything month-by-month and suggest the best strains to cultivate in these two regions with very distinct climates.
What is a marijuana grow calendar?
Cannabis is an annual plant that follows pretty much the same schedule year in, year out. In very simple terms, the grow calendar shows what you can expect in each month of cultivating cannabis outdoors in the US.
The United States of America is large, and it spans several climate zones. Various locations affect questions such as when to plant cannabis outdoors in different ways. Understanding the particulars of your region is crucial to a successful cultivation project.
We’ve decided to create two distinct grow calendars. One has to do with the northern US states, and the other with the southern ones. The guide considers the following factors vital to outdoor pot gardening:
- When to germinate and sow cannabis seeds
- The average temperatures per month
- Day/night lengths per month
- Potential pitfalls in various months
- When to harvest outdoor weed in either region
Technically, the marijuana growing calendar only takes up around half of the year. It would start in April when you’d usually plant your weed seeds and end in October when you collect the colas and call it a day.
There’s a lot of prep work you can do as early as January and February. The colder parts of the year are ideal for clearing your soil of any extras and nurturing it before it freezes. For that reason, our guide is a year-round affair.
Of course, these rules aren’t one-size-fits-all. You’ll have to consider the needs of different cannabis families and each strain in particular. We’re making suggestions based on averages in the northern and southern USA and average traits of your regular marijuana plant.
With that in mind, let’s jump into the nitty-gritty of the outdoor cannabis grow calendar.
Outdoor grow calendar for the northern USA: Month by month
The best time to plant cannabis outdoors in the northern US isn’t officially until April (or mid-May in some cases). There’s a lot to do beforehand to prepare for a bountiful harvest.
We averaged the day lengths and temperatures based on New York, Chicago, and Seattle. We included Alaska in our calculations separately.
Two things to note:
- The northern West Coast has springs and summers with similar average temps. Since we provide ranges, pay attention to warmer spring and colder summer data.
- Alaska receives the most hours of sunlight. The Northwest is second, and then the Northeast.
Let’s dive into the grow calendar for colder-weather American cultivators. We’ll cover germination, flowering, and harvests more generally first, followed by a breakdown month-by-month.
When to plant marijuana outdoors in northern states
When to plant marijuana outdoors? If you’re sprouting your seeds in controlled conditions under CFL lamps (which we recommend), you should be able to take them outside in April. Days are now longer, and the temperatures hit the mid-50s during the daytime.
Remember the following grow calendar exceptions for crop safety:
- If you live in the Midwest, check whether there’s still frost in the mornings before transporting your weed seedlings.
- Wait until May in Alaska. Consider the morning temperatures early in the month and take your baby plants out around that time.
- Autoflowering seed varieties shouldn’t pop before May since they’re much more prone to cold stress.
Outdoor flowering time in northern states
In the North, young plants enter adulthood in June and July, depending on the strain. Autoflowering plants automatically flip to flowering a bit earlier, while photoperiod varieties produce their first pistils in July.
The outdoor flowering time for autos is pretty swift, taking only several weeks. You can expect your non-photoperiod herbs to finish fattening their buds in August.
Photoperiods growing outdoors take a bit longer to develop fully mature colas and cover them in sticky resin. Their flowering period takes up the three full months between July and October. Some cultivars are harvest-ready in late September, others in early October.
When to harvest outdoor marijuana in northern states
The marijuana grow calendar is only a part of deciding when to collect your harvest. Never wait past mid-October to avoid cold stress, bud rot, and a general breakdown in quality, but consider these three factors:
- Is it still warm outdoors? Flowering crops can spend some time in 50-degree weather, but not too much.
- Have you considered the outdoor flowering time? Most strains have a ripening stage of 6 to 12 weeks. Try to get them at least to the minimum requirement, no matter the cold.
- How do the colas look? If they fattened and got sticky, it’s time to collect.
Having discussed the basics, let’s examine the growing marijuana outdoors timeline.
January
With temperatures in the low 10s and barely 11 hours of sunshine, there’s not much you can do in terms of the cannabis grow calendar right after Christmas.
The prep work doesn’t have to start till February. There’s still a winter between you and flourishing cannabis crops. Start looking into interesting strains and learning more about them at this time, and save the hands-on gardening for later in the year.
February
| Northern US | Alaska | |
| Average day length | 9.5 to 11.5 hours | 8.5 to 10.5 hours |
| Average temperature | 22 to 51°F | -8 to 12°F |
When to plant weed outdoors? Not in February, but you could start collecting your equipment for the task. Get your hands on the following:
- Pots of various sizes
- Potting mix and soil
- Nutrients for later stages
- Cannabis seeds
- Other tools and consumables for cultivation
Now’s also the time to prepare the soil with compost and nutrients. If you’re in Alaska or the Midwest, you can hold off for another month.
March
| Northern US | Alaska | |
| Average day length | 9.5 to 13 hours | 10.5 to 13 hours |
| Average temperature | 31 to 54°F | 0 to 24°F |
The grow calendar sees some action in March! Now’s your chance to sprout the seeds. Don’t take them outdoors just yet, though. Instead, keep them beneath warm lamps indoors until the longer April days. You can leave the seedling pots to bask in the sun on nice days, too.
Note: Wait with outdoor autoflowering strains. They don’t need to enter the seedling stage until May.
April
| Northern US | Alaska | |
| Average day length | 12 to 14.5 hours | 13.5 to 15.5 hours |
| Average temperature | 35 to 62°F | 24 to 45°F |
Growing outdoors can officially start in April. 14-hour days by the end of the month and warmer temperatures make it possible to transport the seedlings outside.
Remember, be sure there’s no morning frost before taking the pots outdoors. You don’t want to stress your cannabis babies before they have the chance to strengthen.
May
| Northern US | Alaska | |
| Average day length | 14 to 15.5 hours | 15.5 to 17.5 hours |
| Average temperature | 52 to 72°F | 40 to 61°F |
Now’s the grow calendar moment when Alaskan seedlings see the great outdoors. May is the time of vigorous vegetative growth for everybody else, when the stem elongates, branches pop up, and foliage becomes lush and green.
Note: If growing autoflowering strains, this is when you germinate.
June
| Northern US | Alaska | |
| Average day length | 15 to 16 hours | 18 hours |
| Average temperature | 54 to 81°F | 52 to 71°F |
The amount of sunshine your crops receive in this part of the marijuana grow schedule gets them developing in hyperdrive. Vegging comes to a close, and the first hints of pistils start showing up by the end of the month.
July
| Northern US | Alaska | |
| Average day length | 14 to 16 hours | 16.5 to 18 hours |
| Average temperature | 58 to 85°F | 55 to 73°F |
July marks the beginning of the outdoor flowering time. The long days and plenty of sunshine get your cannabis crops producing pistils. Your autoflowering plants are nearing the end of their life cycle, while the regular photoperiod varieties start displaying signs of gender.
August
| Northern US | Alaska | |
| Average day length | 13 to 15 hours | 14 to 16.5 hours |
| Average temperature | 58 to 84°F | 49 to 66°F |
Alaskan marijuana plants start their outdoor flowering time at this point. Other parts of the northern US see the continuation of ripening, with colas becoming larger and more bud sites popping up.
Autoflowering plants are harvest-ready at this time.
September
| Northern US | Alaska | |
| Average day length | 11.5 to 13.5 hours | 11.5 to 14 hours |
| Average temperature | 54 to 76°F | 38 to 55°F |
Moisture levels get higher in the September section of the marijuana grow calendar. As flowering continues, you might consider bringing your crops indoors to protect them from excessive rainfall and humid air. Be mindful of harsh winds that could bring plant damage, too.
Some shorter-flowering crops are done ripening in the Midwest, while the Alaskan and Northwestern crops are still maturing.
October
| Northern US | Alaska | |
| Average day length | 10 to 13 hours | 11.5 to 14 hours |
| Average temperature | 46 to 64°F | 20 to 33°F |
The temperatures drop in the fall, and the climate becomes hostile to cannabis crops. It’s about time to wrap up outdoor cultivation and bring the remaining plants indoors to finish ripening.
November
Cannabis isn’t one of those sturdy plants that can take November temperatures and survive. The grow calendar ends before fall begins in earnest. After you harvest, treat your soil to get it ready for the year ahead.
A brown mulch of manure, leaves, or woodchips does wonders for outdoor soil during the winter. It’s an insulating blanket that acts as an all-you-can-eat for microbial life, making it perfect for future weed growth.
December
The December marijuana growing schedule is empty! Sit back, relax, and enjoy the fruits of your labor.
Outdoor grow calendar for the southern USA: Month by month
What’s the best time to grow weed in the southern US? How much does the situation differ across the climate line?
The southern half of the US and Hawaii are much warmer than their northern counterparts. Temps are higher, days longer, and humidity levels lower.
Some notes for our south grow calendar:
- We’ve averaged the temperatures and day lengths based on Miami, Los Angeles, and Houston.
- The days are the shortest in Hawaii, and the Southwest Coast receives the most sunshine.
- The central part of the Southern USA is the hottest, while it gets a bit colder near the shores.
This marijuana grow schedule follows the same pattern as the one for northern states. We’ll first provide general information for the essential sections of your cultivation journey, followed by a more detailed discussion of what happens each month.
When to plant marijuana outdoors in southern states
Germination in March is the way to go for the southern US unless you’re cultivating autoflowering strains. In that case, wait for April.
When to start growing weed outdoors in the south, then? April gets around 13 hours of sun a day, marking the ideal time to move your seedling pots to windowsills or your patio. You can do this very early in April in the Southeast, but wait till the month-end in Hawaii and Southwest.
Outdoor flowering time in southern states
Late June and early July are when your plants drop the vegetative growth and start focusing on cola production instead. You’ll notice the first hints of pistils in your photoperiod and non-photoperiod cannabis in the shorter but scorching days at the end of June.
The outdoor marijuana flowering time is slightly longer in the South, mostly because it begins earlier. Of course, you’ll harvest plants with shorter lifecycles sooner, but some can spend as much as four months in flowering.
On the other hand, your autos will eagerly produce buds in July. They’re usually harvest-ready in August.
When to harvest outdoor marijuana in southern states
In the North, figuring out when to plant outdoor strains for a fat harvest is essential, but it’s much less of an issue in the South. You can harvest as late as the end of October. The weather is a bit more humid but still warm enough not to stress your crops.
With this in mind, let’s see what happens in each month individually.
January
The grow calendar doesn’t feature any official action by March in the south, but it’s better to get a headstart. Use January to study your strain of choice, focusing on its climate and nutritional needs.
Pick a cultivar you think you can manage and get your weed seeds to hype yourself up for the steps to follow.
February
| Southern US | Hawaii | |
| Average day length | 10.5 to 11.5 hours | 11.5 hours |
| Average temperature | 49 to 80°F | 67 to 81°F |
Frost is no longer a concern on southern grow calendars in February. Still, it’s too early for germination this month. Use it to prepare everything else, from the pots to the nutes.
March
| Southern US | Hawaii | |
| Average day length | 11.5 to 12.5 hours | 11.5 to 12.5 hours |
| Average temperature | 50 to 81°F | 68 to 82°F |
Despite the warmth, March days are still too short to make this month the best time to plant marijuana outdoors. You can pop your seeds and leave them by windowsills, supplementing with an additional hour or two under CFL lamps.
Don’t germinate your autos yet, but get ready to do so in a month.
April
| Southern US | Hawaii | |
| Average day length | 12.5 to 13.5 hours | 12.5 to 13 hours |
| Average temperature | 55 to 84°F | 70 to 83°F |
The grow calendar days are still getting longer in April, making this the ideal time to take your seedlings outdoors to continue developing in a natural environment.
Pop your auto variants, too, and let them soak in the warmth and sun of the southern spring.
May
| Southern US | Hawaii | |
| Average day length | 13 to 14.5 hours | 13 to 13.5 hours |
| Average temperature | 60 to 87°F | 71 to 85°F |
When to plant marijuana autos outdoors? In May, when the seeds sprout and are ready to take on the rich earth awaiting. Photoperiod variants will be vegging at this time, basking in the sun and developing lush greenery.
Note: You might need to start supplementing with lamps or pick strains with low light requirements from this point forward if you live in Hawaii.
June
| Southern US | Hawaii | |
| Average day length | 14.5 hours | 13.5 hours |
| Average temperature | 60 to 91°F | 74 to 87°F |
Growing outdoors reaches its full glory in southern June. The plants finish up vegging, stretching tall and strong with multiple bud sites. The end of the month brings first hints of pistils on photoperiod variants, while autos perform this majestic function in early July.
Hawaii strains will enter flowering a bit earlier due to the light hour discrepancy.
July
| Southern US | Hawaii | |
| Average day length | 13.5 to 14.5 hours | 13 to 13.5 hours |
| Average temperature | 65 to 93°F | 75 to 88°F |
The shorter yet scorching July days are ideal for bud formation and fattening, and autos finish their flower clusters, starting on trichome production. If you’re growing from regular weed seeds, inspect them for males and separate the pots before pollination occurs.
August
| Southern US | Hawaii | |
| Average day length | 13 to 14 hours | 12.5 to 13 hours |
| Average temperature | 65 to 95°F | 75 to 89°F |
The grow calendar for autoflowers ends here. You collect the now sticky colas and get curing.
Your photoperiod cannabis plants start producing trichomes. If you have a sativa in Hawaii, supplementation with extra grow lights in the evening is a good idea to ensure complete maturation.
September
| Southern US | Hawaii | |
| Average day length | 12 to 13 hours | 12 to 12.5 hours |
| Average temperature | 64 to 89°F | 75 to 89°F |
The days on the marijuana grow calendar might not be getting colder, but they’re shortening. Perform the final flush and inspect your plant for harvest readiness.
Some sativa strains might need a bit more time, but between the temperatures and long summer flowering, most hybrid strains will be perfectly ripe at this time.
October
| Southern US | Hawaii | |
| Average day length | 11 to 12 hours | 11.5 to 12 hours |
| Average temperature | 60 to 86°F | 74 to 87°F |
October is still warm enough for growing outdoors, but you need to watch for excess humidity since moisture rises in the fall. Stay aware of signs of bud rot. If still ripening in Hawaii, transport your pots inside under grow lights or install a temporary grow tent.
November
It’s too cold and dark to cultivate in November. You can follow the same grow calendar steps as you saw in the northern guide and add compost to your soil.
December
Take December to relax, relish your cured buds, and reflect on everything you’ve learned.
Best strains to grow outdoors: Northern states
The northern parts of the US are colder than their southern counterparts. October temperatures easily drop below 50°F during the daytime, and nights get cold quickly.
As such, the cannabis grow schedule here is a bit shorter and more conducive to climate-resilient strains with shorter lifecycles. Indica cultivars are ideal for these regions. Here are some of our favorites.
Expert tip: If it gets super cold where you live, consider autoflowering strain varieties. They go through their entire seed-to-harvest period over the summer, ensuring a healthy harvest in the warmer part of the year.
Northern Lights
Is there a better strain for growing outdoors in northern states? This cultivar is all traditional cannabis. It boasts scents of earth and wood with a lemony tang, a high that locks you to a seat, and yields of sticky flowers that paint your fingers all shades of green.
Skunk #1
The outdoor grow calendar for Skunk #1 starts in March and ends in mid-October, and it’s a stinky affair all the way through. Light up the strain that became synonymous with quality ganja and let the last hints of tension melt off your neck and shoulders.
| Type | Indica-dominant hybrid |
| THC | 18–22% |
| Aroma | Earth, diesel, citrus |
| Effects | Uplifting, sedative, stress-relieving |
| Flowering time | 9 weeks |
| Yield | 14–19 oz./m² indoors / 14–21 oz./plant outdoors |
Blueberry
The cannabis grow calendar becomes a much more exciting matter when you have the potent buds of Blueberry waiting on the other side. This dense plant smells like a fruit salad, yields generous servings of frosty colas, and gets your mouth watering upon the first whiff.
Grandaddy Purple
The entire marijuana growing schedule is simple with Grandaddy Purple, and these candy-tasting buds keep you coming back for more. The harvests are generous and resinous. They get even better when late September nights bring out the purple pigmentation of the buds.
| Type | Indica-dominant hybrid |
| THC | 15–19% |
| Aroma | Fruity, grape, herbal |
| Effects | Relaxing, uplifting, pain-relieving |
| Flowering time | 9–10 weeks |
| Yield | 14–17 oz./m² indoors / 14–21 oz./plant outdoors |
Best strains to grow outdoors: Southern states
The southern part of the US is closer to Ecuador, resulting in longer summers with temperatures regularly hitting the high 90s.
For that reason, the weed grow calendar in this area is longer and more favorable to sativa strains that need more time in the sun. Here are our four favorites, but you’ll find that most strains can thrive where you live.
Jack Herer
The outdoor flowering time of Jack Herer might be a bit longer, but each moment of the cultivation journey is mesmerizing. Titled after the famous cannabis activist, this lemon-tasting, stimulating smoke pays homage to its namesake, invigorating you to take action and enjoy life.
Blue Dream
The best time to start growing weed is now with the gentle hand of Blue Dream. These resinous colas are all about getting you to feel fine. The dessert-tier smoke and the generous output per cannabis plant make the experience enjoyable during cultivation and consumption.
| Type | Sativa-dominant hybrid |
| THC | 16–20% |
| Aroma | Earthy, berry, vanilla |
| Effects | Euphoric, creative, relaxed |
| Flowering time | 8–10 weeks |
| Yield | 14–21 oz./m² indoors / 14–21 oz./plant outdoors |
Amnesia Haze
Follow the weed calendar for an unforgettable October harvest with Amnesia Haze. This intricate blend of landrace cultivars delights with its refreshing smoke and cerebral stimulation. Each deep green crop shimmers in late summer, promising a blissful harvest to come.
| Type | Sativa-dominant hybrid |
| THC | 16–20% |
| Aroma | Wood, fruity, pepper |
| Effects | Energizing, uplifting, stimulating |
| Flowering time | 8–9 weeks |
| Yield | 14–17 oz./m² indoors / 21–28 oz./plant outdoors |
Sour Diesel
Growing outdoors with Sour Diesel can be a challenge, but it’s well worth it. Its fresh smoke packs quite a punch in the psychoactive department, leaving you blissful and free of discomfort. Its massive yields make every ounce of effort return as an ounce of first-rate pot.
Successful cultivation from start to finish
You now have an idea of how the climate changes from North to South US and from month to month. You’re also knowledgeable about how those shifts affect your weed plants. Congratulations, you have a solid knowledge foundation for your outdoor cultivation journey.
Note that this grow calendar is very general. When to plant marijuana and when to harvest cannabis outdoors are still questions that take a lot of adaptation depending on your region, your strain, and most importantly, what you see in your garden.
Why not put your new skills to the test with the highest-quality cannabis seeds from Homegrown? Find a strain that suits your climate and get growing for full jars of the finest pot.
Visit our blog for more guides on everything about seeds, cultivation, harvests, and beyond. Explore the weed world with our resources in your corner.
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