Cannabis can grow in a remarkably wide range of environmental conditions, and naturalised populations have sprung up all over the world. Now, seed companies have developed outdoor strains that are not only able to grow and thrive in specific habitats, but that are also able to consistently produce high levels of cannabinoids.
Climate is the biggest consideration when it comes to choosing an outdoor strain. People living in the far north of the northern hemisphere or the far south of the southern hemisphere (in the boreal or sub-polar climate zones) will be severely restricted in their choice of strain. The further away from the equator one is located, the shorter the growing season will be before the winter cold makes it impossible to continue.
Temperatures may also be consistently too low to support many strains of cannabis, even in the height of summer. Most cannabis strains require consistently warm temperatures for vigorous vegetative growth; while they prefer slightly cooler temperatures during flowering, they still cannot tolerate excessive cold or frost. In general, cannabis can be grown successfully up to the 60th parallel N/S—although there are reports of hemp in Scandinavia as far north as the 67th parallel.
Light intensity reduces with distance from the equator, so even in summer plants will have fewer lumens available to them than their temperate and tropical counterparts. Cannabinoid production (particularly THC) is fundamentally linked to light intensity, as hemp and ruderalis strains found in northern latitudes are low in THC (although they may be high in CBD and other cannabinoids).
Some commercial strains have been developed for far north/south climate zones. These strains complete their growing cycle very early, and have been bred to withstand frost and cold—while still producing significant amounts of cannabinoids including THC.
Outdoor cannabis in the temperate zones
The temperate climate zones of the world are typically divided into two sub-zones: cool-temperate zones (such as Northern and Eastern Europe), and the warm-temperate zones (such as Southern and Western Europe).
Characteristics of cool-temperate climates are:
- Short, mild summers
- Long frosty winters
- A single outdoor harvest per year
Characteristics of warm-temperate climates are:
- Long, sunny summers
- Mild winters
- Seasonal variation in day length
- Temperatures remain favourable until as late as early December, meaning that late flowering varieties can be planted (such as sativa)
If growing in warm-temperate zones, the possibilities are almost endless. In these climates, the likes of Mexican Sativa and Purple Haze can thrive. But these certainly aren’t the only options. A selection of strains suitable for the warm-temperate zones can be found here.
Outdoor cannabis in the equatorial and tropical zones
Though it might sound completely desirable to grow cannabis in tropical or equatorial areas of the world, these zones also face their limitations in growing cannabis outdoors.
Characteristics of equatorial and tropical climate zones are:
- Lack of seasonal variation in day length (meaning a constant 12/12 light cycle)
- Extremely hot temperatures
In a constant 12/12 light cycle, temperate strains will begin flowering before they have had the chance to enjoy a defined vegetative period. This means that plants may not grow to be very big or very tall. This can be mitigated with supplementary lighting during the vegetative period. However, in the absence of supplementary lighting, equatorial zones should focus on equatorial landraces and commercial hybrids that are very sativa dominant.
Other climate considerations when selecting outdoor strains
Aside from temperature and hours of daylight, the single most important environmental variable is moisture level. There can be huge differences between locations on the same latitude which are entirely the result of variations in precipitation—in the northern hemisphere, the wettest zones typically lie along the western coastline of a land mass, while in the southern hemisphere, they are usually on the east coast.
This phenomenon is due to the direction of the prevailing winds that carry moisture across the oceans to the land. There are exceptions to this rule. For example, the eastern U.S. is generally more humid than the west. This is due to north-to-south ocean currents causing the Pacific Ocean to be cooler than the Atlantic (which is warmed by south-to-north currents from the equator) at the same latitudes.
Generally speaking, the closer one is to an ocean, the more likely it is that the climate is humid. The interior of a landmass (particularly a large continent such as Africa or Eurasia) is more likely to be arid. If located in a humid or coastal climate zone, choosing strains that are well-adapted to resist mould is highly advisable.
Most cannabis strains are naturally more suited to semi-arid conditions, so growers in the interior or continental zones will often be less restricted in their choice. However, people in extremely arid zones are also restricted due to cannabis’ substantial water requirements.
5 Best strains for outdoor growing
1. Ruderalis Indica Cannabis Seeds
90% indica – 40-50 days of flowering
Our Ruderalis Indica is an early flowering strain that can thrive in almost all climates, even in cool/cold temperatures. Its impressive resistance makes it perfect not only for growers who do not benefit from optimal growing parameters, but also for beginners looking to obtain a satisfying harvest.
Do you want to know more about this sturdy cannabis plant sought for by many medicinal cannabis users? Read our strain focus on Ruderalis Indica here.
2. Mexican Sativa Cannabis Seeds
70% sativa – 50-70 days of flowering
The Mexican Sativa strain is a great choice for any grower looking not only for quality fragrant buds, but also for a fast-flowering plant that does not require too much care. And with its famous sandalwood flavour, Mexican Sativa is not only a delight to grow, it is also a definite treat for the taste buds.
Our expert breeders crossed a cultivar from the southern Mexican region of Oaxaca with the fierce Durban Poison and the fast-flowering Pakistani Hash Plant to obtain this result. In other words, the best in only a few weeks!
Mexican Sativa grows best in warmer, southern European climates. It also grows extremely tall, making this strain a perfect outdoor endeavour.
3. Early Skunk Cannabis Seeds
35% sativa / 65% indica – 55-65 days of flowering
This strain can survive virtually any climate, and will produce gargantuan harvests of luxuriant, dank buds shimmering with frost! Do you want to know more about this generous early riser? Read our strain focus on Early Skunk here.
4. Jamaican Pearl Cannabis Seeds
85% sativa – 50-75 days of flowering
Another big yielder among our outdoor strains is the delicious Jamaican Pearl. This strain can survive colder weathers as well as indoor growing thanks to its rock-solid genetics: a cross between Marley’s Collie and Early Pearl, this Caribbean strain did not lose any of its tropical, sweet potency.
Between the buoyant cerebral effect and the sweet and spicy fruitiness, it is truly an amazingly relaxing, surprising strain.
5. Sensi Seeds’ Outdoor Mix – the best outdoor cannabis strains in one pack
80% indica – 40 days of flowering
Not quite sure which cannabis strain to choose? Sensi Seeds can put an end to your doubts! Our Outdoor Mix includes several strains perfectly suited for outdoor growing, including a couple of the aforementioned favourites.
They are mostly indica, and the selection consists only in strains that can handle all climates, including cold temperatures. The outdoor mix comes in a 25 seeds pack, to ensure that you will enjoy yourself and get a reasonable amount of surprises. If you are a beginner in outdoor growing, they will definitely deliver a nice, heteroclite harvest of quality buds, and in only 40 days!
- Disclaimer:Laws and regulations regarding cannabis cultivation differ from country to country. Sensi Seeds therefore strongly advises you to check your local laws and regulations. Do not act in conflict with the law.