Highest THC Strains in Canada & the US

February 24, 2019

Highest THC strains

With the demand for increased potency growing amongst marijuana users, cannabis farmers and growers are becoming tasked with having to create even stronger strain of the highly desired cash crop.

Due to the widespread legalization of weed in the U.S and Canada, home growers are becoming a lot more creative in order to cultivate plants that have higher concentrations of THC than formerly known. Although these strains are supposed to be restricted, they still eventually make it on to the street and in to the hands of the customers. While the earliest strains known used to have concentrations of 10% THC, the demand for “good weed” has consistently driven the regular concentration of THC in street weed to over “20%”. There are a lot of things that go into determining the strength and potency of a particular cannabis strain. However, in this article, we will discuss the strains with the highest concentration of THC in Canada.

What are the best strains according to specie

It is important to know that these strains possess qualities in line with their unique specie characteristics. While sativa and Indica are the two most popular cannabis species, each will often present strains that have specific characteristics and strength that could differ from other members in the family. Knowing that, there also exists a class of strains formed from the hybrid between these two that integrate the best qualities from each specie.

The Best Qualities of Sativa strains

Known for their characteristic long and branched leaves, sativa strains are generally uplifting in nature and are more likely to survive in unfavorable weather conditions than their counterparts.  Some of the highest sativa strains include;



As one of the highest THC containing strains in the sativa specie, the destroyer contains around 20% THC. First grown by CannaBiohen, it was cultivated from a mix of Thai and Mexican genetic resulting in a pure sativa strain.

When ingested/smoked, it provides an energetic effect that is both uplifting and euphoric. Some of the destroyer’s most vital quality is the speed at which it grows, it is able to withstand harsh weather conditions and has been known to grow faster than most Thai blends. Flowering in just a bit under 12 weeks, it has a powerful lavender smell and is sweet to the taste.

Ghost Train Haze


Popularly regarded as one of the strongest strains ever grown, the Ghost Train Haze is technically a hybrid. It is 30% Indica and 70% sativa and is perhaps the most famous hybrid in the market that is sativa dominant.

In effect, this strain delivers the typical sativa qualities including the energetic and uplifting effect and can last a bit longer than most. While the result hasn’t been very conclusive, Ghost train Haze was once tested to contain 28% THC, a result that isn’t very shocking given its strength and widely known potency.


Perhaps one of the most aptly named, the Kilimanjaro specie is named after the rather famous landmark and the highest mountain in the continent of Africa. It also has one of the highest concentrations of THC in the sativa specie.

It has a pleasing aroma and carries a rather fruity taste. With up to 20% THC content, the Kilimanjaro strain is very popular among users in Canada and the US and has been widely known in the Europe for a long time.

Train wreck

The train wreck is one of the easily grown strains of the sativa specie. It has a very high yield and is one of the most readily available strains. It has a bit of Indica and is dominantly sativa as it is cultivated from crossing Thai, Mexican and Afghani.

The strength comes from its hybrid qualities but being a sativa dominant specie, it manages to maintain the most favorable characteristics of sativa.


Indica strains

Anyone who is familiar with cannabis knows that the Indica species have a higher concentration of THC than their counterparts. Even in this family of high THC containing plants, there exist strains that possess outstanding concentrations making them perhaps the most potent strains in the world.

Indica typically grows with short and stubby features and carry a rather pungent smell especially when compared to their more pleasing and fruity sativa counterparts. Their growth is not as versatile as the sativa species and they tend to grow well in mountainous areas. The highest Indica strain include;

Kosher Kush

The Kosher Kush is both popular and highly demanded. Having won several awards throughout its existence, it contains over 21-29% of THC. This variation isn’t strange as different parts of the plant will typically contain different concentrations of THC depending on their growth conditions. It grows fast, yields well and when consumed, has a powerful effect that is loved by many.

Afghan Kush

Kushes generally are some of the strongest strains of cannabis. Being from the Indica family, one can immediately tell that they do in fact have a really high THC concentration. The Afghan Kush is quite popular and has been tested quite a lot to establish the exact concentration of THC. While the number often varies like a lot of other strains, it typically goes from anywhere between 16% -25%.

Afghan Kush has a high yield and can be grown in both outside and indoor locations.

Purple Kush

The Purple Kush is one that is highly revered. While it has no impressive qualities like taste or yield, it does have a magnanimous content of THC making it very potent. It has been tested to contain over 27% THC, a feature that provides the record setting levels of highness that is both loved and feared.

When ingested, Purple Kush comes with a peppery taste that lingers on for a while and was initially grown for the specific purpose of winning a cannabis competition.

Critical Kush

Unlike the other strains listed above, the Critical Kush, isn’t purely Indica and has all of the traits of the specie.

It is made from a cross of other heavy hitters and has a THC range of over 20-25%. It is quite easy to grow and has good yield, a quality that isn’t particularly known in the Indica familiar. When smoked, critical Kush comes with a calm buzz that provides a relaxing effect that can last hours.

Overall, whether you’re in Canada and the US the method in which you absorb your specific strain will dictate its effectiveness.