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Grow Calendar – Northern Edition
Growing outside in the Northern US? Jump ahead to the month of your choice:
We’ll start with the northern parts of the United States. Generally, the outdoor growing season in this part of the country does not officially begin until mid-May. However, there’s plenty to do before that time comes. In fact, taking the time to prepare now, will make this summer’s grow harvest even more bountiful.
Here’s the deal:
You can start preparing to grow in February. For this reason, there is no reason to wait.
Seeing that the marijuana plant has different needs throughout its lifespan, this Outdoor Grow Calendar covers the entire growing period. It also considers the large size of the United States by listing the average day lengths and temperatures for both the northern half and the southern half of the country.
Tip: make sure to download my free Grow Bible for more information
Northern United States
This section refers to the top half of the United States, including Alaska.
A Few Notes:
- Averages are based on Seattle, Chicago, and New York
- If you are growing on the northern West Coast, your springtime temperatures will be the warmer average, and your summer averages will be cooler than average
- The most amount of sun is found in Alaska, with the Northwest coming in second
Average Day Length: 9 hours 30 minutes to 11 hours 15 minutes
Average Temperature: 22 degrees to 51 degrees
Average day length: 8 hours 30 minutes to 10 hours 30 minutes
Average Temperature: -8 degrees to 12 degrees
It’s cold outside. Now is the time to pick out your seeds and complete your orders. Many Northern growers choose Indica dominant plants because of the short growing season.
Read the article “Best marijuana seeds for my climate” if you’re not sure what seeds grow best in your area
In places like New York and Boston, it may seem like the frosty, cold temperatures will never end. However, if you start your plants indoors, you can extend your growing period so that you can grow any strain. You can sprout your seeds indoors in a controlled environment with artificial light at the end of February.
What’s more, if you want to make clones, you should germinate your seeds at this time. Keep your mother plants inside until it’s warm enough.
Create a cozy indoor growing space with a CFL grow, 18 hours of sunlight and of course, some fresh air. Keep your grow area between 68 and 77 degrees. Check out “how to germinate marijuana seeds” for more on creating a cozy environment for germination.
At this point, you can also begin prepping your soil if you aren’t in Alaska or the Midwest. After the last frost, loosen up your soil by adding worms and compost.
Average Day Length: 9 hours 30 minutes to 12 hours 50 minutes
Average Temperature: 31 degrees to 54 degrees
Average day length: 10 hours 40 minutes to 13 hours 15 minutes
Average Temperature: 0 degrees to 24 degrees
It’s starting to warm up on the coasts, and the days are getting very long around Seattle and Portland. Growing time is getting close. If you haven’t already ordered your seeds, do it now.
You should also have your mother plant ready by the end of this month if you plan to clone.
If you are ready to go, you can start sprouting your plants in a windowsill at the end of the month. Make sure they get some good sunlight and keep a good watch on the day length. By this time, areas near Seattle are receiving more than 12 hours of sunlight, while Alaska has 13.
However, most of the country will not have as much sunlight. In this situation, you can provide it for them. If your plants aren’t getting enough sunlight, set a lamp over your plant a few extra hours each day. That way, you won’t have to worry about premature flowering.
Average Day Length: 12 hours 40 minutes to 14 hours 25 minutes
Average Temperature: 35 degrees to 62 degrees
Average day length: 13 hours 15 minutes to 15 hours 45 minutes
Average Temperature: 24 degrees to 45 degrees
Congratulations, it’s April! That means flowers, followed by May showers. The middle of this month marks the beginning of long days, with everyone having at least 14-hour days by the end of the month. Once the days are that long, you will not need any more artificial lighting.
Your windowsill plants will not need any more help with light once the days reach 14 hours, and your seeds will find it easy to sprout.
By the end of the month, it’s safe to take your plants outside – especially if you are on the West coast. Simply put them in a container and put them outside, bringing them indoors at night. Midwest growers may want to make sure the risk of frost has passed first. Alaskan growers will need to wait another month or place the plants in containers and bring them inside during cold nights.
If you created a mother plant, it’s time to make clones. Need help with that? The article “How to make clones” explains the process.
Average Day Length: 14 hours to 15 hours 40 minutes
Average Temperature: 52 degrees to 72 degrees
Average day length: 15 hours 45 minutes to 17 hours 45 minutes
Average Temperature: 40 degrees to 61 degrees
It’s finally Spring – even in Alaska. If you live on the Alaskan coast, it’s probably okay to start placing your plants outside. Stay vigilant for frost, of course. The Alaskan interior should wait until the middle of the month – just to be safe.
If you have autoflowering seeds, you’ll begin sprouting them the second half of this month. They need three months of summer to grow. Given that in some parts of the Midwest and Alaska, that’s all the time you will have before the freezing temperatures return, so work quickly. Expect your harvest to be ready mid-August.
Average Day Length: 14 hours 50 minutes to 15 hours 55 minutes
Average Temperature: 54 degrees to 81 degrees
Average day length: 17 hours 50 minutes to 18 hours 15 minutes
Average Temperature: 52 degrees to 71 degrees
June is when your plants will experience the most growth – especially between June 18th and June 24th. At this time, you’ll see your autoflowering plants grow rapidly as they begin to develop flowers. Your non-autoflowering plant will also speed up, thanks to the warming temperatures.
Average Day Length: 14 hours 5 minutes to 15 hours 55 minutes
Average Temperature: 58 degrees to 85 degrees
Average day length: 16 hours 30 minutes to 18 hours 15 minutes
Average Temperature: 55 degrees to 73 degrees
During this hot month, your autoflowing plants will develop large flower clusters, while some non-autoflowering plants will grow their first pistils.
If you decided to use regular (non-feminized) seeds, now is when you’ll need to be checking for male plants. Keep an eye on the side branches and quickly remove them. You’ll recognize the males because they will develop flowerheads at the root of the side branch. These flowerheads will look like two small balls resting on a short, thin stem.
Female plants, however, will have drop-shaped calyxes with two white pistils protruding from them.
Average Day Length: 13 hours 5 minutes to 14 hours 55 minutes
Average Temperature: 58 degrees to 84 degrees
Average day length: 14 hours to 16 hours 25 minutes
Average Temperature: 49 degrees to 66 degrees
Remember those autoflowers that sprouted back in late May? It’s now time to harvest them. Cut the flower heads and hang them upside down in a dark place to dry. Dry them at room temperature – don’t try to speed up the process by making it too hot. It should take about 10 days.
You’re done when the branchlet cracks when you bend it.
Near the end of the month, most areas will have less than 14 hours of sunlight. Alaska is the exception. Once this happens, non-autoflowering plants will begin their last flowering phase.
Average Day Length: 11 hours 40 minutes to 13 hours 20 minutes
Average Temperature: 54 degrees to 76 degrees
Average day length: 11 hours 30 minutes to 14 hours
Average Temperature: 38 degrees to 55 degrees
If you are growing non-autoflowering plants, (photoperiod plants) they will start developing more pistils and flowerheads at the beginning of this month. You’ll want to make sure they stay dry during this time – perhaps, build them a shelter, or take them indoors.
The wind can also be a problem during this month as the seasons start to change. In any case, prevent your plants from falling over by adding a net or using bamboo sticks.
Fall officially begins the end of this month, but it will be a slow transition on the West Coast and in Alaska as the sun tends to linger around a bit longer.
Average Day Length: 10 hours to 13 hours 5 minutes
Average Temperature: 46 degrees to 64 degrees
Average day length 11 hours 30 minutes to 14 hours
Average Temperature: 20 degrees to 33 degrees
‘Many plants can take a short mild freeze (30-32°F). But of the temperature stays below freezing for more than a few hours, it could kill plants.’ ~ Jorge Cervantes
Autumn is officially here, and many outdoor-grown plants have bloomed. Unfortunately, this is a high-risk time for most northern growers. Especially in areas where it’s cold (Midwest and Alaska) or wet (Pacific Coast), you need to keep an eye out for bud rot.
If you notice any signs of bud rot, it’s time to harvest. An early harvest is better than none at all. Read more about bud rot in the article “How to prevent Bud Rot”
Grow Calendar – Southern Edition
Growing outside in the Southern US? Jump ahead to the month of your choice:
Just like growers in the northern states, by all means, get a head start. As I have said, you can start as early as February. Sure, the true outdoor growing season doesn’t begin until mid-May, but why wait? After all, there is a popular saying: “the early bird gets more bud,” or at least that’s how I remember it.
In the southern states, the last frost signals “go time”. After that, use this calendar to help plan the year’s grow season.
Southern United States
This section refers to the bottom half of the United States, plus Hawaii.
A Few Notes:
- Averages are based on Los Angeles, Houston, and Miami
- Southern West Coast growers can expect the most sun and the coolest average temperatures year-round.
- Central areas will have the hottest summers, while the Southeast will experience the hottest spring and fall.
- The shortest summer days are in Hawaii.
Average Day Length: 10 hours 30 minutes to 11 hours 40 minutes
Average Temperature: 49 degrees to 80 degrees
Average day length: 11 hours 15 minutes to 11 hours 45 minutes
Average Temperature: 67 degrees to 81 degrees
Time to buy seeds! For most of the southern United States, the threat of frost has passed and it’s just about time to start growing. Because of the extended growing season in some areas of the south, it’s safe to choose sativa dominant plants. If you opt for an Indica, the first thing to remember is how hot your summers generally become.
Read the article “Best marijuana seeds for my climate” if you’re not sure what seeds grow best in your area.
You can also begin sprouting your own seeds indoors, but be sure they stay warm enough until they can go outdoors. Seedlings prefer a temperature between 68 and 77 degrees. Of course, some areas such as Hawaii and southern Florida, boast February temperatures like these, however, your plants will also need 18 hours of sunlight. Due to this, you will need to invest in some CFL grow lights until the days get a bit longer to sprout seeds early.
For more information on germinating your seed indoors, read “how to germinate marijuana seeds.”
February is also a great time to prep your soil. Loosen it up a bit by adding compost and worms.
Average Day Length: 11:30 hours 30 minutes to 12 hours 30 minutes
Average Temperature: 50 degrees to 81 degrees
Average day length: 11 hours 45 minutes to 12 hours 20 minutes
Average Temperature: 68 degrees to 82 degrees
The warmest areas of the United States are starting to feel like summer, and the interior is no longer at risk of frost. Assuming you already have your seeds, you can begin sprouting plants in the window sill . Your plants need at least 12 hours of sunlight, so if the days are not quite long enough yet, add a lamp an extra hour a day to make sure they receive enough.
If your plants do not get enough sunlight, they may start flowering early – and you do not want that.
Tip: make sure to download my free Grow Bible for more information
If you decided to use a mother plant, spend some time tending it. It needs to be ready by the end of the month if you plan on using your clones outdoors.
Average Day Length: 12 hours 30 minutes to 13 hours 30 minutes
Average Temperature: 55 degrees to 84 degrees
Average day length: 12 hours 20 minutes to 12 hours 55 minutes
Average Temperature: 70 degrees to 83 degrees
April raises the temperature just a bit and lengthens days significantly (except in Hawaii). You’ll notice the longer days around the middle of the month, with most southern areas reaching 13 hour days by the end of April. At this point, you won’t need those lamps in your windowsill anymore. Make sure your plants receive as close to 13 hours of sunlight as possible, and your seeds should easily sprout.
In fact, if you live in the Southeast, it’s probably safe to take your plants off the windowsill and into the fresh air. The Southeast tend to have the warmest spring temperatures in the southern half of the United States. As a rule of thumb, if it’s 70 degrees, you’re probably okay to let them sit outside during the day. Remember to bring them indoors at night!
If you created a mother plant in late February, now is the time to start making your clones. Read the article “How to make clones” for more information
Average Day Length: 13 hours 10 minutes to 14 hours 15 minutes
Average Temperature: 60 degrees to 87 degrees
Average day length: 12 hours 56 minutes to 13 hours 20 minutes
Average Temperature: 71 degrees to 85 degrees
Spring has arrived – although, in some places, it already feels like summer. Go ahead and place your plants outside permanently.
Plant your autoflowering seeds by the middle of the month. By that time, they’ll have plenty of sunlight to grow, and the temperature is just right. You’ll be ready to harvest the beginning of August. As a note to any Hawaii growers, do not choose strains that require higher than average amounts of sunlight for outdoor growing, as Hawaiian summer days are the shortest in the country.
Average Day Length: 14 hours 15 minutes to 14 hours 45 minutes
Average Temperature: 60 degrees to 91 degrees
Average day length: 13 hours 20 minutes
Average Temperature: 74 degrees to 87 degrees
June is when outdoor marijuana plants grow the most – specifically between June 18th and June 24th. Autoflowers begin to develop flowers, and non-autoflowers grow faster.
June is also when Hawaii starts to experience the shortest days in the country, as compared to California, where outdoor plants receive up to 90 extra minutes of sunlight.
Average Day Length: 13 hours 30 minutes to 14 hours 20 minutes
Average Temperature: 65 degrees to 93 degrees
Average day length: 13 hours 5 minutes to 13 hours 20 minutes
Average Temperature: 75 degrees to 88 degrees
The hottest month of the year produces large flower clusters on autoflowers while your non-autoflowers may show their first pistils.
If you used regular (non-feminized) seeds, look for pesky male plants. Watch those side branches for flowerheads at the bottom of the side branches. They will look like two small balls resting on a short, thin stem. If you see them, quickly remove them. Females, on the other hand, will have drop-shaped calyxes with two white pistils protruding from them.
Average Day Length: 12 hours 45 minutes to 13 hours 50 minutes
Average Temperature: 65 degrees to 95 degrees
Average day length: 12 hours 30 minutes to 13 hours 5 minutes
Average Temperature: 75 degrees to 89 degrees
You can harvest your May autoflowers! Cut off the flower heads and hang them upside down in a dark place to dry. Don’t try to rush the process by messing with the temperature- dry at room temperature.
Drying should only take about 10 days. Test for readiness by bending a small branch. If it cracks, it is ready! Read more on this in the article: “How to harvest marijuana plants.”
You may also be able to harvest your non- autoflowers since the days have dropped below 14 hours and you must do so before 13. If you are in Hawaii or the Southeast, due to their shortened outdoor growing season, you should choose autoflower strains with short growing cycles.
Once the days drop below 14 hours, non-autoflowering plants start their last flowering phase and begin to die. If you have limited amounts of daylight, bring them indoors and use lamps to extend the growing season a little bit longer.
For non-autoflowering (photoperiod) plants that are not ready to harvest, you’ll see more pistils and flowerheads. Protect them from the wind and keep them dry by building a shelter or bringing potted plants inside. You can also stabilize them with bamboo sticks.
Average Day Length: 11 hours 50 minutes to 12 hours 50 minutes
Average Temperature: 64 degrees to 89 degrees
Average day length: 11 hours 57 minutes to 12 hours 30 minutes
Average Temperature: 75 degrees to 89 degrees
Fall comes at the end of this month, but some parts of America may not notice, at least temperature-wise. However, the shorter days near the end of the month are a clear indicator that the growing season is nearly over.
Many plants will be ready to harvest during this month if you haven’t already. Read my article “How to harvest marijuana plants” for more info.
Average Day Length: 10 hours 50 minutes to 11 hours 50 minutes
Average Temperature: 60 degrees to 86 degrees
Average day length 11 hours 20 minutes to 11 hours 55 minutes
Average Temperature: 74 degrees to 87 degrees
Autumn is here and the outdoor growing season is officially over. While plants in most of the southern United States should have already bloomed, there may be some that finish up this month. If your plants are still growing at this time, be especially careful of cold, wet temperatures. This can cause bud rot, which can ruin your harvest. The heartland of America is most at risk for this.
If you notice any signs of bud rot, harvest immediately – some is better than none. Read more in the article “How to prevent Bud Rot”
There are many climate regions in the United States, each impacting your plant’s growing season. Be that as it may, marijuana loves mild temperatures and plenty of sunlight, which can be found in many parts of the country. The important thing to remember is that marijuana loves sunlight. As a result, growing outdoors means you need to time your growing for when it can receive the most of it.
Do you grow in the United States? Did we leave something out?
Let us know in the comments, and we’ll update this calendar. Together we can share knowledge to grow the best marijuana in the USA.
Here’s to a great harvest!
The founder of I Love Growing Marijuana, Robert Bergman is a marijuana growing expert that enjoys sharing his knowledge with the world. He combines years of experience, ranging from small-scale grows to massive operations, with a passion for growing. His articles include tutorials on growing... [read more]