Calendar for Growing Cannabis Outdoors: Europe and the USA

Growing cannabis outdoors is ideal if to cultivate weed the old-school way. You don’t have to invest in expensive light panels and grow tents. 

You get incredible yields, and it’s cheap. What’s not to love?

However, there are a few things you should consider while growing outdoors. 

For example, your local climate dictates how you grow and nurture your cannabis plant. Even though cannabis is resilient, it still needs proper time and environment to grow bountiful buds.

To help you understand the cannabis growing process for your climate, we have created this cannabis growing calendar. Our calendar focuses on Europe and the USA. It will show you what to expect during the phases of the growing season and what to do to ensure your plant grows healthy. 

Ideal Strains Depending on Your Region’s Climate

Your location dictates how your plant grows. In addition, you need to choose strains that are compatible with your climate. 

For example, if you live in Northern Europe, choose a strain that can sustain without heat and sun, whereas your strain should be resilient to pests and mold due to high humidity and heat if you come from Southern Europe. 

Similarly, those in the southern parts of the USA must choose strains that thrive in the abundance of direct sunlight and have longer growth cycles because of longer growing seasons than the northern parts.

Below is a short guide on which strains would work for your region.

Northern Europe and Northern Parts of the USA

Choose Indica-dominant or auto-flowering strains for these regions. Indica strains have evolved to grow in cool, mountainous areas with short summers and intense frost over time. Auto-flowering plants also work well because they do not rely on sunlight to transition from vegetative to flowering.

And if you manage to get your hands on an Indica-auto-flowering hybrid, you can potentially grow plants quickly with terrific cold tolerance. 

Southern Europe and Southern Parts of the USA

On the other hand, Southern Europe and certain parts of the USA experience warm temperatures with long days and growing seasons. Thus, we recommend using Sativa-dominant strains.

Sativa cannabis plants have evolved in such climates and thrive in sunny, humid climates better than Indica strains. Additionally, you must ensure your strains are pest and mold resistant if you live in the coastal regions. For instance, Sativa strains with fluffy buds tend to resist bud rot better than others. 

Phase-by-Phase Grow Calendar

This calendar will look at each growth phase of cannabis, from preparation to harvest, considering your local environment. Let’s get started.

• Preparation (February)

Like everything else, it’s important to plan to grow cannabis outdoors. Start purchasing seeds, growing accessories, containers, nutrients, trellis structure (or anything else you need to support the plants) during February. Do not forget to pick a nice sunny spot to grow the plants. 

The growing location can be a garden bed in your backyard or balcony. Below are some pointers on preparation as per regions.

The preparation for all the four regions — Northern and Southern Europe, North and South USA — is largely the same. Everything remains the same, except the seeds. 

For northern Europe and Northern USA, you must choose Indica-dominant strains as they are more resilient to cooler climates and shorter growing seasons. On the other hand, for Southern Europe and the South USA, you can choose from the array of Sativa-dominant strains. 

Lastly, talk to expert growers here on Growdiaries to figure out which strains are ideal for your specific region and go ahead from there.

• Germination and Sowing

After February, the weather will start to turn warm in all regions. This is the time to kick off your cultivation.

Let’s look at each region's germination and sowing phase in more detail.

Northern Europe (March to April)

Once the weather starts to turn in March, you can start your germination process. You can use germination pods or propagator kits to provide the seeds with great conditions required to pop them.

However, it’s also possible to germinate seeds easily using other methods. Firstly, soak the seeds in water for 24 hours. Some growers let it sit for 36-48 hours, but that’s very risky. Next, place the seeds in a paper towel and sprinkle some water. Note that the towel must be moist — not too wet or dry — and put it in a ziplock bag. 

It may take anywhere from 4-7 days for the seeds to germinate. If they are slightly older, they may also take about ten days. Next, fill a small cup or pot with soil and transfer the seeds into it. Place the pot in a warm location with less light until the seeds germinate. 

As a rule of thumb, we recommend germinating the seeds indoors in this region because the outdoors may still be too cold for the seeds to pop.

Take your time here, as you have until March to April to germinate the seeds.

Southern Europe (March)

In Southern Europe, you need to be quick with germination as the growing season approaches faster than in the northern regions. While March is the perfect time to germinate the seeds, you can begin as early as late February.

If you begin in March, you can start germinating the seeds outdoors. Just ensure the outdoor temperature is over 16 degrees Celsius before you start. 

Northern USA (February to March)

In the northern states of the USA, the weather will still be cold, but it’s a good time to germinate your seeds to extend your plant’s growing period.

You must sprout your seeds in a controlled environment with artificial lighting; begin at the end of February for the best results. Keep the germinating area warm and cozy CFL grow lights and some fresh air with a temperature around 19°C to 25°C. 

You can start preparing your soil once the last frost has passed. Start by loosening up the soil by adding compost and worms. Once the days start getting longer, you can move your seedlings to the windowsill or balcony so they can bask in some sunlight.

And if you are using auto-flowering plants, you can start the germination process in the second half of May as they need shorter growing periods. Or, you can go ahead and start the process even with autoflowers if you want to harvest twice in one growing season. 

Typically, photoperiod plants may grow outdoors for 8-9 months, whereas autoflowers require only 3-4 months. Thus, if you want more yield, you can also plant autos. 

Southern USA (March to April)

The Southern USA gives you the luxury of more extended germination periods, so you can start by germinating your seeds directly on the windowsill or balcony as you will have enough sunlight for the seeds to pop. If the days aren’t long enough, you can add artificial lighting for an hour or so. You can also germinate indoors to keep the seeds warm if you prefer. 

If you live in the Southeast region, you can start planting the seeds directly in the containers. However, it takes a bit longer for the seeds to pop in pots, so you can use the paper towel methods and transfer the seeds into the containers as usual. 

Remember that as long as the outdoor temperature is over 21°C or 69.8°F, you can let the seedlings sit out in the sun. For auto-flowering plants, you can plant the seeds outdoors in the third week of May — there will be enough sunlight for them to grow well.

• Transplanting the Seedlings Outdoors

If you have been sprouting the seeds outdoors, now is the time to transplant the seedlings outdoors into the growing bed or pots. Let’s take a look.

Northern Europe (May)

May is mid-spring — the ideal time to prepare your cannabis for the heat of summer. So, as long as the temperature in your region is around 12°C to 15°C (53.6°F to 59°F) with minimal risk of frost or rain, you can transplant your seedlings outdoors. 

Ensure your plant has enough nutrients, sunlight, and water to grow properly during its veggie state.  

Southern Europe (April)

In Southern Europe, you can transplant the seedlings earlier than in northern parts, say, April, because the temperatures would be around 19°C (66.2°F) with long days, so the seedlings can enjoy the sun. 

Everything else remains essentially the same as Northern Europe.

Northern USA (April to May)

In the northern states of the USA, the long days of around 14 hours start by the middle of April. So, by the end of April, you can move your plants outdoors.

We recommend bringing the plants indoors at night if there's a cold-weather forecast or frost, especially if you live in the Midwest. However, the spring will finally arrive in May, and you can leave your plant outdoors for the entire day and night without worrying about frost.

Southern USA (May)

In the Southern USA, May marks the arrival of Spring, but it already starts feeling like summer in most states. So, go ahead and transplant the seedlings outdoors into the growing bed or container without worrying about frost. 

• Training, Pruning, and Topping

Once you transplant your cannabis, they will finally transition into the veggie phase in a couple of weeks. They will experience immense growth during these months, but to ensure they grow an even canopy and get the maximum yield, you must train and Top your plants. 

We explain how to train your plants for each region in the below sections.

Northern Europe (June to August)

In Northern Europe, your cannabis plant will experience a peak vegetative stage from July to August, thanks to abundant sunlight. 

Here, you can try training methods like low-stress training and topping to ensure they grow well. 

Remember to give your plants at least a week to recover well before practicing any other method on them. And stop any training by the second week of August.

During these months, your plant will start taking on a lot of mass. Keep on the maintenance, and your plants will naturally bloom soon by the end of August.

If your specific region experiences early fall, you can transition your plant into bloom. To do this, develop a light deprivation system to trick your plant into thinking the days are shorter; it will automatically start flowering.

Southern Europe (May to August)

Come late spring and early summer, your plants will experience peak growth in Southern Europe. This is the time to train and Top your plant. Use methods like Topping, LST, and super cropping for the best results.

Also, once the temperatures reach around 23°C, there will be a lot of sunlight. So, you won’t have to worry about light, but you must maintain a strict watering cycle.

You must also look out for any signs of pests or mold. It is best to avoid such problems as they are often irreversible.

Northern USA (June to September)

The Northern USA experiences the longest veggie season, where your plant will grow the most between June and July. Even the auto-flowering strains grow rapidly during these months.

By the beginning of September, your cannabis will grow flowerheads and pistils. You must ensure that they stay dry so take your plants indoors if there’s any forecast of rain or high humidity.

In these regions, too much wind can also be a problem. So, you can use bamboo sticks and nets to support your plant. 

You can even start using various training methods like Topping, LST, ScrOG, and super cropping during this time.

Your plant will be ready to transition into bloom by the end of September, so you need to give it the right nutrients before this.

Southern USA (June to July)

If you are growing your cannabis in the Southern USA, it will experience the most growth during the end of June and July. 

Since these states experience the ideal conditions for most cannabis strains, you can start training your plant by the end of June. Use standard training techniques like Super Cropping, Topping, and ScrOG. 

July will be the hottest month of the year, so your plant will start showing its first pistils. Ensure you provide adequate water and nutrients to your plant during this month for a bountiful yield.

If you are growing an auto-flowering plant, it will start producing large, bushy buds during the end of July. 

• Harvesting the Plant

Finally, it’s harvest season. To know if your plant is ready to harvest, look at the trichomes. If 70% of the trichomes are cloudy, your plant is ready. 

Once you cut off the flowers, you can use various curing techniques to dry the buds. 

In the below sections, we share some pointers on harvesting as per your region.

Northern Europe (September and October)

By the end of September, days become shorter in Northern Europe and the weather will start turning cold. Take your pruning scissors and start collecting the buds by early October. 

We recommend harvesting in a progressive method instead of cutting all the buds at one time. This allows all the buds to mature properly. 

Southern Europe (September to November)

Southern Europe enjoys a longer harvesting season of around three months, so take your time with it. Let your plant grow the buds on its own time. Then, you can start harvesting the flowers at the end of September. 

Most of the cannabis strains would be ready to harvest by mid-October, but some strains like Landrace may take longer. If your strain takes longer to bud properly, don’t worry — harvest it by mid-November.

Northern USA (October)

In the northern states of America, October marks the arrival of autumn with your cannabis plant completely blooming. You can reap your rewards during October, but don’t take too long — the bitter cold may harm your buds.

If you live in the Midwest or Pacific Coast, you must watch out for bud rot. Harvest your plant as soon as possible if you notice any signs. This is why it’s recommended to train your plants through the LST or Low-Stress Training method to prevent bud rot. LST, coupled with Topping, will increase the airflow and deter bud rot. As a general rule of thumb in the Northern USA, an early harvest is better than no harvest.

Southern USA (September to October)

In the Southern USA, your plant will be ready to harvest by September, when the fall comes to an end. This is when you can harvest your plant.

Some strains may keep growing buds even in October. In this case, you must be wary of wet, cold weather, which can cause bud rot. Again, if you notice any signs of bud rot, harvest your plant as soon as possible.

Important Dates for Outdoor Cannabis Cultivation

The above section breaks down the cannabis cultivation season, but it may not always be accurate since local climates vary. So, it’s also helpful to time your cultivation with seasons. Remember the following dates:

• Spring Equinox — Time to start germinating your cannabis seeds
• Summer Solstice — Clear indication that your plant is nearing the end of bloom, and you can harvest in a few weeks. Don’t forget to keep an eye on the trichomes and the pistils. You can check the trichomes through a jewelry loupe. If you don’t have one, wait until 60-75% of the pistils turn amber. 
• Winter Solstice — Now is the time to dry and cure your buds

Important things to consider when growing outdoors

pH

Many growers underestimate the pH when they grow cannabis outdoors. Just like you maintain the pH of plants indoors, it is extremely important to take care of the pH of plants growing outdoors.

When growing plants outdoors, you must choose between containers or natural soil. Although natural soil is undoubtedly a better option, growing the plants in containers is a good idea. 

Why? Well, if you grow in natural soil, you'll have to ensure that the soil is at the right pH. You can check the pH by purchasing a soil pH testing kit. The best pH for cannabis plants growing in soil is around 6 to 7. Note that you will have to adjust the pH of the soil along with the water you use to irrigate the plants.

All this can be tedious for some, so it's best to stick to containers to prepare a good growing media to grow the plants. In addition, it's easy to check the pH of the soil in containers. Note that if you mix in soilless media such as peat with natural soil, the pH needs to be around 5.8 to 6.8.

Size of the container

The size of the container is incredibly important when growing cannabis outdoors. Typically, most growers start with 5-gallon pots for small plants; however, if you choose strains that tend to grow huge, you must go for 10-gallon containers and above.

Remember, there are chances of the plant toppling and falling over if the containers are too small or large. For instance, if the pots are too small, the plants can simply fall, whereas plants in large containers can snap into two against strong winds.

Training

Indoor growers train their plants using various techniques, including Topping, LST, Super Cropping, Lollipopping, etc. Most of these techniques are used to increase the yields.

However outdoor growers must be careful while training their plants. For example topping the plants growing indoors is effective to divide the main cola into several colas and increase the yields. But, Topping also creates weaker colas if you overdo it. 

Weak tops can snap into two against strong winds. Therefore, it's best to top only once or maximum twice when growing outdoors. Instead, you can LST the plants and bend the colas to the sides of the container to produce an even canopy.

Support structure

Growing outdoors is not as easy as planting a cannabis plant in a container and hoping for it to grow well. First, you'll need to provide a solid support structure to ensure the plants can support their weight.

Trellising is an excellent way to offer support to heavy colas. However, you'll need to provide support as soon as you plant the seeds or seedlings in the container. Vertical trellising is done by installing poles around the four corners of the plants. You can choose metal T posts, PVC, wood, or bamboo poles, but metal T posts are the best because they are sturdy and last long. You can also use metal cages used to grow tomatoes.

Summary: Calendar for Growing Cannabis Outdoors: Europe and the USA

Cannabis cultivation is easy, and with the right timing, you can enjoy bountiful yields and enjoy your homegrown weed with your friends. Just remember to germinate your seeds under the right conditions, transplant them at a suitable location, and offer your plant the right nutrients and water when it’s growing.

When it’s time to harvest, use the right method to cut the buds and cure them. 

If you’re too late, you may end up with damaged buds. Conversely, harvesting too early will also produce damaged flowers.