Seed To Harvest: Cannabis Grow Calendar for the US

As many perks as indoor growing may have, many growers still prefer the old-school way of growing cannabis outdoors. The perks are unmatched, especially considering you don’t have to spend so much on the grow lights, and then there’s the aspect of it being a more “natural” method of cultivation. 

But one perk that outdoor growing does not enjoy is a year-round season. Instead, if you’re growing cannabis outdoors, you have to rely on the seasons and time your cultivation accordingly. So, to help you accomplish this, we’ve made this cannabis grow calendar for the US, detailing a monthly schedule on what to do and what to expect with your cannabis plant. 

What is a Grow Calendar?

A growing calendar is nothing but a short guide that highlights the progress of your cannabis plant based on the seasons or months of the growing period. This calendar goes through the stages of your plant growth, giving you an idea of what you can expect, and some tips on what to do during each month of the growing season. 

A grow calendar however is not a strict schedule; it will only give you an idea of how to time your cannabis grow. This is because, in the US, the growing season is not year-round in most states. 

On average, you can start prepping your cannabis cultivation in February, and since cannabis takes 3 to 4 months to grow fully and mature, you can expect the final results of your operation by October. That’s an average growing season. 

However, you must still factor in other aspects like the strain and size of your cannabis, your local climate, growth conditions, etc. — these factors also affect your plant’s life cycle, which may extend or shorten based on them.

Note on the US Grow Calendar for Cannabis Plants 

This grow calendar covers the entire lifespan of the cannabis plant based on the average growing season, day lengths, temperatures, plant characteristics, etc. The information for the northern states is based on New York, Chicago, and Seattle, and the same for the southern states is based on Los Angeles, Houston, and Miami. 

The US can be divided into multiple parts based on the weather, such as:

• Alaska with the most amount of sun and coldest temperatures 
• Northern West Coast with warm springtime and cooler summers than average 
• Southern West Coast with the most sun and cool average temperatures (in the south)
• Central states with the hottest summers 
• Southeast states with the hottest spring and fall 
• Hawaii with the shortest summer days (in the southern US)

So, keep these in mind and plan your cannabis cultivation in the US accordingly. Let’s get started. 

1. February 

Northern US

In the north, it is still cold during this month, so you cannot start growing your cannabis just yet. But that doesn’t mean you can’t prepare. Instead, take this time to start shopping for your cannabis cultivation. 

Some of the basic things you can start purchasing now include containers, high-quality soil or potting mix, jerry cans, watering cans, irrigation tools, fertilizers and supplements, and even cannabis seeds. When picking the seeds, it is advisable to pick a strain that’s adept to cold climates and tends to grow smaller. 

If you live in Boston or New York, you can even start sprouting your seeds in February but you’ll have to do it indoors in a controlled space since the temperature will still be frosty. For this, all you need is a CFL light on an 18/6 light cycle, a temperature between 68°F to 78°F (20°C to 25.5°C, and damp paper towels for germination. 

This is also the time you can start preparing the soil if the temperatures are not so frost — most states outside of Alaska and the Midwest. Here, you can start adding compost and worms to loosen up the soil. 

Southern US

If you live in the southern part of the US, you don’t have to restrict your operators strictly to indoors. In this region, the chance of frost may have already passed and you can start growing cannabis outdoors. 

Thanks to the longer growing season your plant will enjoy, you can pick plants that grow tall and wide — they’ll have enough time to grow to their full potential. Remember, seedlings grow best in a temperature between 68°F to 78°F, so ensure that the temperatures are in that range when you start germinating the seeds.

If the temperatures are still not warm enough, you can always germinate the seeds indoors and start preparing the outdoor soil by adding worms and compost to loosen it up. 

2. March 

Northern US

During this time, the coastal areas in the north will be warming up with the days getting longer in Seattle or Portland regions. The growing season is about to begin, so if you haven’t ordered the seeds, it’s time to do so now. 

In most regions in the north, you should start sprouting your cannabis seeds by the end of March — you can even do so at the windowsill at this point. Just make sure they get enough sunlight during the day. 

You can wait another month too if you are growing autoflowering cannabis. However, if you start sprouting your cannabis at this time, you can grow two rounds of autoflowering cannabis by the end of the growing season — consider sprouting the seeds now. 

In most regions, the sunlight may not be enough, but you can always set a small lamp next to your plant to give it that extra light it needs to sprout properly. 

Southern US 

This is when things will start getting warm in the south of the US, and you might feel like summer is already here. So, if you haven’t sprouted your seeds yet, it is time you do so. Again, you can germinate your cannabis seeds on the windowsill but make sure they get enough sunlight; if not, you can add an extra lamp, which will work just fine. 

3. April 

Northern US

By the second or third week of April, most regions in the northern US will start experiencing long days of over 14 hours. Thankfully, you no longer need any more light and the growing season is properly on now. 

If you’re growing cannabis on the windowsill right now, the natural sunlight should be enough at this point and your cannabis plant or seedling will grow just fine without any artificial lighting. 

After the third week, you can start transplanting your cannabis outdoors, especially if you are based on the West Coast. In some regions where the nights may still be cool, you may have to bring the plants in your room during the night but you can leave them out during the day. This is especially true for the Midwest where the risk of frost may still linger. 

If you live in Alaska, it’s time to hold your horses for one more plant. You can try letting your plants grow outdoors during the day and bring them in during the night, but your local weather will determine that. 

Southern US 

The southern states will be in a much better state at this point. The temperatures will be high and the days will be significantly longer, especially after the second week of April. If your days are longer than 13 hours, you can leave your plants on the windowsill without any additional lights. 

In the Southeast regions, growers can also bring their plants outdoors since this region has the warmest spring compared to other parts of the US. In fact, as long as the outside temperatures are above 70°F or 21°C, you can bring your plants outside during the day. 

Again, there’s always a risk of frost in most regions of the Southern US, so you want to bring your plants indoors. 

4. May 

Northern US 

May marks the beginning of Spring, so you can start growing cannabis outdoors, even in Alaska at this point. Of course, you’ll have to be wary of frost in Alaska even now, so if you live in interior Alaska, consider waiting a couple more weeks before moving your plant outdoors. 

If you haven’t germinated your cannabis seeds yet, do so now. Autoflowering plants need three summer months to grow properly, so don’t be too late — this is all the time your auto cannabis may get in Alaska or the Midwest. 

Southern US 

The same trend follows in the Southern US with the spring arriving and days getting a lot warmer. Transplant your cannabis plants outdoors without having to bring them in at night anymore. 

As for autoflowering plants, it’s time to start germinating the seeds if you’re only growing a single round of auto cannabis this growing season. They will enjoy the right temperatures and plenty of sunlight during this month and be ready for harvest by the first week of August. 

5. June 

In both the North and South US, June is the month when cannabis plants will grow the most, especially from the 18th to the 24th of the month. Even the autoflowering cannabis plants will grow quickly and start developing flowers by the end of this month. 

So, make sure you take care of your cannabis plant at this time and give it all the nutrients it needs. The days are already long enough and the temperatures are warm, so you don’t have to worry about those things. Your biggest concern should be aiding your plant to grow as big as possible during this month. 

6. July 

If you live in the North US, you must’ve picked strains that flower early, and these plants will start showing first signs of pistils by July. Plants growing in some southern regions may also start transitioning to the flowering phase at this point as the days grow shorter. 

If you have used regular, non-feminized seeds at this point, you need to start looking for any signs of male plants and remove them before they end up pollinating your female plants. 

To do so, look at the roots of the side branches. Male cannabis plants develop side flowerheads that look like two small balls on a short stem. On the other hand, female cannabis plants will develop calyxes, which are drop-shaped, in the same spot. These calyxes will have two white pistils protruding. 

If you are growing autoflowering cannabis, you’ll notice the buds growing big during this month, so start preparing for harvest — it’s just around the corner. 

7. August 

It’s time to harvest autoflowering cannabis plants that started their life back in May. So, begin by cutting the buds off and hanging them upside down in a dark room. The drying process takes around 10 days, so don’t try to speed up the process; allow them to dry at room temperature. 

After about a week of drying, you can start testing your cannabis buds for readiness. All you need to do is bend a small branch — if it snaps, the flower is dry enough for the curing process. 

On the other hand, photoperiod cannabis plants will start to flower by the end of this month, switching from the pre-flowering stage of July. This will happen if the days are shorter than 14 hours in your region. 

In some southern states, you may even be able to harvest your photoperiod cannabis plants — this should happen if the days are shorter than 13 hours. In other regions, photoperiod cannabis plants will enter their last flowering stage. You can always extend their life by bringing the plants indoors and supplementing them with artificial light. 

If your cannabis plants are not ready for harvest yet and have developed flowerheads, you need to take some precautions to protect them from the wind. You can do so by building a greenhouse shelter — this will keep them dry — or bring them inside; if rain is not a concern, you can even use bamboo sticks to support them. 

8. September 

Northern US

In the Northern states, the winter is soon arriving and it’s time to take your photoperiod plants indoors. You need to make sure your cannabis plants stay dry during this month and are protected from the winds — if you can’t bring them indoors, consider building a shelter for them. 

By the end of September, the season of fall will begin but the Midwest will experience a slow transition and Alaska will still have long days for a while. So, act accordingly. 

Southern US 

In the southern states of the country, fall will arrive by the end of the month but in some states, you may not notice the difference at all. The temperatures may remain the same but the days may get a bit shorter by the end of the month. This is a sign that the growing season is coming to an end. 

Be ready to harvest your cannabis plant now. Keep an eye on the buds so you know the perfect time for harvesting; otherwise, you’ll be left with over-mature buds with more CBG than THC. 

9. October 

In the US, the autumn season will begin and your cannabis plant will have bloomed if it hadn’t already in the previous month. 

If you live in one of the colder states, especially in Alaska, or Midwest, or on the Pacific Coast, you need to be vigilant about bud rot. The same applies to the heartland of America, where cannabis is prone to bud rot and other mold problems. 

Keep a close eye on the buds and harvest the buds if you spot even a single sign of bud rot — the days will be cooler and wetter, which makes your plant susceptible to bud rot. Do not wait around — mold can compromise your entire yield, so cut your losses and harvest early. 

You should also keep an eye on the temperature at this point. Most cannabis varieties can survive a few hours of freezing cold, but anything more than a few hours can kill them. So, harvest the plants if the temperatures dip too low. 

Additional Tips on Growing Cannabis in the US 

If you want to grow cannabis in the US, the above-mentioned grow calendar for the US should give you an idea of what to expect during the growing season, but it’s just a general guideline. So, to help you understand the process better, here are a few more insights on growing cannabis in the US. 

1. Best Time to Plant Autoflowering Cannabis Outdoors

In most regions of the US, you can grow autoflowering cannabis plants between April and October — this is when the weather is ideal. But for the best results, we recommend growing auto cannabis during the first few months of the season, starting from April, since the temperatures will not be too high during the initial months of the season. 

In any case, you should keep your local climate in mind. If you live in a region that is still too cold or wet during the start of the growing season, consider germinating your auto cannabis indoors or waiting for a while. 

2. Germinating the Seeds at the Right Time 

One of the common mistakes many growers in the US make is that they germinate the seeds too soon. In this case, if you start germinating your seeds too soon, your cannabis plant may start flowering too soon and fail to finish its cycle properly. 

So, depending on your local climate, you need to decide when your growing season will come to an end. If it ends early, you can start germinating your plant early; if not, you should consider waiting until the end of March or April for germinating your cannabis seeds. 

3. Pre-Flowering Duration for Outdoor Cannabis 

For photoperiod cannabis plants, the pre-flowering phase can last from 1 to 3 weeks, but this entirely depends on the local climate of your region and your plant’s strain. But do not take this phase lightly — this is when you need to check if your cannabis plant is male or female. 

It is tricky to know when the pre-flowering phase of your cannabis plant occurs, so use the US grow calendar mentioned above and your strain’s characteristics to know when you can expect your plant’s pre-flowering phase to start. 

4. Flowering Stage Duration for Outdoor Cannabis

On average, photoperiod cannabis plants have a flowering phase that goes on for 8 to 10 weeks, but this depends on the strain, local weather, and day length. In some regions, you don’t need to worry about it — your plant will mature at the right time without the risk of frost. 

In some regions, especially where the growing season is short or you’ve picked a long-flowering strain, you may have to hasten the process. In such a case, you can place a tarp over your plant for 12 hours to force it to flower early. This will protect the plant from the cold that arrives with the winter solstice. 

Summary: Seed To Harvest: Cannabis Grow Calendar for the US

There’s your cannabis grow calendar for the US. Remember, this is not a rulebook for growing cannabis in the US, but a general guideline that gives you an overview of what to expect during each month of the growing season in the US based on the local climate and daylight hours. 

In any case, this calendar is a foundation for your cannabis operation in the US, but it’s only a starting point. What will help you grow cannabis in a much better way, along with this US grow calendar for cannabis, is reading up as much as you can about cannabis, maintaining a grow diary, and using high-quality seeds and other peripherals for your cannabis plant. 

To know more about growing cannabis like a pro, stay tuned to our blog. We post regular grow guides on how to grow cannabis that will help you become a much better cannabis grower in the long run.