When you’re considering what seeds to buy in order to cultivate your own marijuana plants, you’ll need to know what you are looking to achieve in order to compare the different strains. For many growers, having a the best high THC seeds is tantamount to having an incredible plant.

A word of caution though: high THC content which is quoted by seed sellers and growers is not always a given. Achieving a high THC content is highly dependent on the amount of care the plant gets during its growth, as well as the methods used to cultivate your plant. To get really great THC content you need to make sure you are aware of what requirements that particular plant has for nutrients, light and other factors to ensure it is grown healthily and happily.

What is THC?

To give it its correct name, Tetrahydrocannabinol (THC) is one of the many ingredients found in cannabis. It is the active chemical that gives you a sense of being ‘high’, and is one of the oldest hallucinogens known to man. There is historical evidence of THC being used as a herbal remedy as long ago as the first century AD and is still today understood to have various medical properties as well as being a recreational drug.

A marijuana plant contains around sixty chemicals which can be classed as psychoactive. Out of all of them, the two which are recognized as being the most potent and effective are THC and CBD (Cannabidiol). There is some evidence to say that CBD in some way neutralizes or dilutes the effects of THC, so when looking for a good THC strain you might want to consider its potential CBD levels too.

Medical marijuana

Although still out for debate, there is a growing supply of anecdotal evidence demonstrating how marijuana can have medicinal properties for the user. Back in 2004, an FDA doctor speaking to congress on the topic of marijuana as a medicine stated that it could never be used as such due to the difficulties in testing active ingredients for safety and usefulness. He said that the wide variations in active ingredients from plant to plant made it too tricky to identify a ‘dosage’ as such, and therefore was unable to recommend it for medical uses.

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Top 10 THC Strains

However, the FDA has remained open to advice and scientific research into marijuana and other cannabinoids, and the recent decriminalization of marijuana for medical uses in some US states is evidence of the direction in which the pendulum is swinging.

From the small number of scientific studies, as well as anecdotal evidence it has become clear that THC, as an active drug, can be used to treat some medical conditions with success. THC has been shown to have a positive effects such as:

• Pain relief
• Appetite stimulation in anorexic patients
• Antiemetic (stops nausea and vomiting)
• Treatment and prevention of glaucoma
• Treatment of epilepsy
• Treatment of asthma
• Psychiatric treatment including bipolar disorder, social anxiety and depression
• Treatment of autoimmune diseases

There are many other reported incidents of THC providing a benefit to sufferers of a wide range of illnesses. If you are unwell, then you should always consult with a qualified medical practitioner for conventional treatment too, but if you are looking to optimize for high THC content for medical reasons, you may find this list useful.

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Top 10 THC Strains

#1 OG Kush – 18% THC

Best for: Stress relief, chronic pain and migraines

Depending on where you come from, OG can either mean ‘original gangster’ or ‘ocean grown’. Whichever name you prefer, this California originating strain is a heavy hitter in terms of THC content. Its neon green leaves and orangey red stigmas produce big popcorn shaped buds literally dripping with resin. With a heritage that is said to go back to the Hindu Kush strains from India and Afghanistan, OG Kush is one of the most potent weeds around and has long lasting, relaxing effects.

We have reviewed different OG Kush Strains:

• Regular OG Kush

• Cali Connection Tahoe OG Kush

• Reserva Privada OG Kush Feminized

• Type: Indica
• Height: Medium
• Flowering time: 8 weeks
• Awards won: Spannabis Cup 2010 (2nd)
• Yield: Low
• Feminized: Yes
• Autoflowering: No
• Growth difficulty: Moderate
• THC level: High, around 18%
• CBD level: Low, usually less than 0.5%

#2 LSD – 22% THC

Best for: Anxiety, PTSD, pain relief and anorexia

The LSD weed strain is a potent contender from the experts over at Barney’s Farm. By crossing a classically high THC Skunk with an equally potent Mazar, Barney’s Farm have developed a hard hitting, knockout weed strain with phenomenal levels of THC. The yield is high, and with average THC content in excess of 22% and low CBD, this is one you should definitely consider if you’re aiming to optimize for THC.

We have reviewed different LSD seeds strains:

• Regular LSD Seeds

• Barney’s Farm LSD Feminized Seeds

• Type: Indica dominant
• Height: Short
• Flowering time: 6 – 7 weeks
• Awards won: High Times Cup 2008 (3rd)
• Yield: High
• Feminized: Yes
• Autoflowering: No
• Growth difficulty: Moderate
• THC level: Very high, in excess off 22%
• CBD level: Low, usually less than 1%

#3 Sour Diesel – 17 to 21% THC

Best for: Mood enhancing, treating depression, ADD / ADHD, bipolar disorder

We love Sour D, and you will too once you’ve enjoyed its energizing, cerebral high and long lasting effects. The notable diesel like aroma gives way to a quick and powerful punch of THC that seems to last and last. The effects are mainly mood enhancing, although it does serve to relieve some milder pains and aches too. The plant is tall and thin, reaching up to 6 feet when grown indoors and yielding a very high crop of around 550g per m2 or more. The aroma, however, is strong, so if you’re looking for a stealthy grow you should give consideration to your ventilation and odor control.

We have reviewed a couple of Sour Diesel strains

• Regular Sour Diesel Seeds

• Super Silver Sour Diesel Haze Seeds

   

• Type: Hybrid
• Height: Tall
• Flowering time: 10 weeks or more
• Awards won: High Times Plant of the Year (2005)
• Yield: Very high
• Feminized: No
• Autoflowering: No
• Growth difficulty: Easy to moderate
• THC level: High average tests of 17% and up to 21%
• CBD level: Typically well under 1%

#4 Pineapple Chunk – 20% THC

Best for: Heavy stone, couch lock, treating pain, anxiety and stress

Another Barney’s Farm  wonder weed which deserves a mention for its unbelievable THC content is the inimitable Pineapple Chunk. Insanely sweet and delectably sticky, this is one weed that delivers on taste and effect every time. Barney’s Farm cleverly crossed their popular Pineapple strain with their Cheese / Skunk #1 to produce something packed with flavor and insanely strong. THC is typically well over 20%, with 25% or more being claimed by some growers. Delivers a strong couch lock and a rewarding yield every time.

We have reviewed a Pineapple strains

• Barney’s Farm Pineapple Express Autoflowering Feminized Seeds

• Type: Indica dominant
• Height: Medium to tall
• Flowering time: 8 weeks
• Awards won: None
• Yield: Very high
• Feminized: Yes, only
• Autoflowering: No
• Growth difficulty: Easy
• THC level: Very high, in excess of 20%
• CBD level: Medium to low, usually around 1.1%

#5 Big Buddha Cheese – 20% THC

Best for: Heavy stone, couch lock, treating pain, anxiety and stress

Produced by Big Buddha Seeds in the UK, this stain is a totally unique and very interesting one to try. The producers crossed original Cheese weed with their own pure Afghani male, resulting in this amazing little plant that will simply knock your socks off. All the fragrance and flavor of the original Cheese are present, but with the generous yield and high THC content of the Afghani delivering an even better result. The high is uplifting and very long lasting, making Big Buddha Cheese a great investment for those looking for something a bit different.

We have reviewed a couple of Cheese strains

• Big Buddha – Bubble Cheese Feminized Seeds

• Big Buddha – Blue Cheese Feminized

• Blue Cheese Cannabis Seeds

• Barney’s Farm – Blue Cheese Feminized Marijuana Seeds

• Green House – Cheese Feminized Marijuana Seeds

• L.A. Cheese Weed Seeds

• Type: Indica dominant
• Height: Medium
• Flowering time: 8 weeks
• Awards won: None
• Yield: Very high
• Feminized: Yes, only
• Autoflowering: No
• Growth difficulty: Easy
• THC level: Very high, in excess of 20%
• CBD level: Under 0.3%

#6 Jack Herer – 18 to 20% THC

Best for: Balanced high, treating depression and anxiety, relieving arthritis

Acclaimed by many as one of your ‘bucket list’ weeds, Jack Herer is well known as being a stunning experience if you can get them to grow successfully. The smell and flavor pay a nice homage to both the Haze and Skunk lines in its ancestry, with earthy, piney tones mixed with fresh, peppery hints. The hit is fast and hard, very cerebral and with a comfortable, painkilling body stone that lasts for a generous time. The THC is high, although not as high as some at around 20% or so. The moderate amounts of CBD at 1.5% might put some off, but we feel it balances out the high and makes this a stunning all round product.

We have reviewed a couple of Jack Herer strains

• Advanced Seeds – Auto Jack Herer Seeds

• Auto Jack Weed Seeds

• Type: Sativa dominant
• Height: Tall
• Flowering time: 8 to 11 weeks
• Awards won: 14 in total, including 2 High Times Cups and 7 High Life Cups
• Yield: Medium
• Feminized: Yes
• Autoflowering: Yes
• Growth difficulty: Moderate
• THC level: High, around 18 – 20%
• CBD level: Medium, around 1.5%

#7 Satori – 23% to 28% THC (crazy high!)

Best for: Creativity, concentration, depression, sleep disorders and novice growers

A less well known strain from established producers, Mandala Seeds, Satori is incredibly potent and tests as having some of the highest THC levels of any plant on the planet right now. The highest recorded from this strain was in excess of 28%, although you’ll be aiming to achieve around 22 – 25% growing at home. These seeds are naturally resistant to spider mite, and grow strong and tall, making them easy to pack into rows to boost the yield. The effect is very cerebral and creative, with a long lasting relaxing effect that can help with sleep disorders and anxiety.

• Type: Sativa dominant
• Height: Tall
• Flowering time: 8 to 10 weeks
• Awards won:
• Yield: Medium to high
• Feminized: Yes
• Autoflowering: No
• Growth difficulty: Easy
• THC level: Very high, around 23% – 28%
• CBD level: Unknown

#8 Sannies Herijuana IBL – 25% THC

Best for: Very high potency, pain relief, insomnia, pest resistance

This is a great strain for those looking for that extra punch that you probably haven’t seen in years. The THC content of Herijuana is reliably high, always in the region of 25%, which makes this a desirable plant from both the medical and recreational point of view. Indica dominant, this plant actually grows like a sativa in the early days, but when it comes to flowering time you’ll see the indica traits in full bloom. Because of its vigorous branching, this is a good contender for SCROG growing with success. Highly recommended for those who love a good, strong indica.

• Type: Indica dominant
• Height: Medium
• Flowering time: 7 to 9 weeks
• Awards won:
• Yield: Medium to high
• Feminized: Yes
• Autoflowering: No
• Growth difficulty: Easy
• THC level: Very high, around 25%
• CBD level: Unknown

#9 Train Wreck – 15% THC

Best for: Functional high, pain relief from migraines and joint pain, treating insomnia

For a long time this powerful strain was only available as a clone, but thanks to the boys over at Homegrown Fantaseeds, you can now grow the legendary TrainWreck direct from seed. It’s a sativa dominant strain, but the indica in its genetics helps to fill out the plant with semi dense buds and sizeable kolas. The hit is instant and straight to the head, with a long lasting mellow feeling that leaves you with a functional, lucid high.

We have reviewed a Train Wreck strains

• Green House Train Wreck Feminized Seeds

• Type: Sativa dominant
• Height: Medium to tall
• Flowering time: 8 – 10 weeks
• Awards won: IC420 2009 (3rd)
• Yield: Medium
• Feminized: Yes
• Autoflowering: No
• Growth difficulty: Easy
• THC level: High, in excess of 15%
• CBD level: Low, between 0.5 – 0.8%

#10 AK 47 – 20%+ THC

Best for: Daytime use, pain management, relieving nausea, movement disorders

A highly popular weed strain, AK47 has been designed to knock you on your ass with no holds barred. In testing, this strain consistently produces plants with over 20% THC, delivering a pleasantly strong cerebral high and treating all forms of pain with great success. Although a sativa led plant, one of the main attractions of AK-47 is its relatively short flowering time and shorter plant height, making it good for indoor grows and a faster than average turnaround.

We have reviewed a couple of AK 47 strains

• Vision – AK 47 Seeds

• Lowlife AK 47 Autoflowering Feminized Marijuana Seeds

• Serious AK47 Feminised Marijuana Seeds

• Automatic AK47 x Auto Hindu Kush

• Critical 47 Weed Seeds

• Advanced Seeds – Auto Kaya 47 Seeds

• Royal Queen – Royal AK Seeds

• Royal Queen Royal AK Automatic Feminized Seeds

• Type: Sativa dominant
• Height: Medium to tall
• Flowering time: 8 to 9 weeks
• Awards won: High Times Cannabis Cup 2011 (3rd), Indica Cup (HTCC) 2003 (2nd)
• Yield: Medium
• Feminized: Yes
• Autoflowering: No
• Growth difficulty: Easy
• THC level: High, 20%+
• CBD level: Low, under 0.5%

That is the current pick of the best of the best for high THC content. We’d love to hear from you about your own preferences for high THC seeds, so either leave a comment below or check out our forum to share your input with others.