While growing cannabis can be a challenge in-and-of-itself, there are some strains that are particularly difficult to grow. Challenging cannabis strains can range from feral plants limited to one geographic location, without interference or genetic modifications, as well as modern hybrids that have specific needs.
If you have picked up on growing cannabis quickly, or are a more experienced grower looking for a challenge, we have put together a list of the most difficult cannabis strains to grow.
Columbian Gold is a 100% pure Sativa and is a classic Landrace strain out of Columbia, meaning it is an indigenous strain that was not crafted by breeders in a cannabis farm. This is one of the reasons that Columbian Gold can be a particularly challenging strain to grow.
This strain is a high-altitude plant with a large stature and long flowering periods. The flowering time for an indoor grow is 70-90 days. Outdoors, this strain is usually ready for harvest towards the end of November. Due to the extensive flowering cycle, it can be easy to make errors with this strain. In addition, this strain does best outdoors due to its size and natural mold and pest resistance, but it can be grown indoors if the grower stays on top of pruning it. The benefit of this plant is that its size makes for impressive yields – indoors you can expect around 350 grams and up to 600 grams for an outdoor-grown plant.
Columbian Gold has an average THC potency of 19% and the pure Sativa genetics make it ideal for daytime use. The buds have a primarily musky citrus smell with a hint of skunky tones. In fact, this strain has been used as a parent for many others including Skunk #1. The effects of this strain start with a mental clarity and uplifted focus; some users may even feel giddy and giggly with this strain. It is particularly beneficial for patients suffering from muscle spasms, chronic pain, fatigue or depression.
ACDC is a perfect hybrid at 50% Sativa and 50% Indica genetics and was developed by crossing Ruderalis and Cannatonic. While it contains a lower THC level of around 0.42% to 1.2%, but it has an impressive CBD to THC ratio of 20:1.
ACDC is a particularly picky strain to grow, which makes it a challenge. It likes a stable and consistent climate between 68 and 80 degrees Fahrenheit. In addition, as a high CBD strain, it is quite sensitive to overfeeding. During the vegetative state it is best to feed half the recommended nutrients, increasing to a full feeding during the flowering period. ACDC grows in any medium and has a naturally bushy structure that requires little training; regular pruning is recommended. The flowering time is approximately 10 weeks – in colder climates, this will be extended. Outdoor grows typically have slightly higher yields, but overall ACDC produces an average yield.
This strain has a unique aroma and flavor of skunk and earthy, mixed with sweet tones. The effects lean towards Sativa, resulting in a strong euphoria that brings happiness and calm. The high CBD content of this strain makes it ideal for treating chronic pain, multiple sclerosis, anxiety, seizures, nausea and migraines.
Headband is a Indica-dominant hybrid that comes from OG Kush and Sour Diesel. This strain is 60% Indica / 40% Sativa and is named after the particularly cerebral effects.
This strain has a moderate to difficult grow difficulty. Well known for the small popcorn-type buds, Headband requires training in order to improve the yield. A grow medium of soil based SCROG (screen of green) or hydroponic will greatly benefit the yield and bud quality. Headband has a flowering time of 9-10 weeks and is a good strain for both indoor and outdoor growing. However, this plant does prefer warmer climates and does best in a temperature of 68-80 degrees Fahrenheit.
This strain has THC levels of 17-24%, sometimes up to 27%, with 0.5% CBD. Headband has smaller buds, but a big flavor composed of hints of lemon and diesel that make for a surprisingly smooth taste. This strain has a strong euphoric and creative high that can last for several hours, however it can cause spaciness so not ideal for getting things done. However, it is a great strain for managing chronic pain, anxiety and mood disorders.
Chocolate Thai is a strain that was bred from a pure Thai strain. Thai itself is a Landrace Sativa, similar to Columbian Gold. It has been said that the original Thai strains are impossible to find, but any strain that originates from these genetics are said to be hard to grow. However, growers like DarwoH are keeping these genetics alive by producing strains such as Chocolate Thai, which is one of the most popular “Thai” strains.
Chocolate Thai is a strain that prefers warmer temperatures. This strain has a lengthy flowering cycle of 65 to 98 days, which contributes to its difficulty. Many of these plants had a tendency to hermie and died easily, but the genetics have been improved recently and have been used in several hybrids. Getting a Chocolate Thai strain through 14 weeks to yield is quite an impressive feat!
When grown properly, this strain has a moderate THC level of 12-16%. The effects are Sativa-dominant and result in an upbeat and creative cerebral high. As a result, this strain is successful at managing depression, insomnia and muscle spasms.
Perhaps the hardest strain to grow is known as Dr. Grinspoon. This strain is coined after a Harvard professor of the same name. It was produced by Barneys Farm and was the second prize winner of ‘Cannabis Cup’.
Being a Landrace Sativa contributes to it being particularly hard to grow, but the real difficulty lies in the structure of the buds. This particular plant can take a long time to flower and the buds are extremely airy, taking ages to develop any real weight. In addition, the stems and buds are quite brittle. The structure results in small yields and can take 13 to 14 weeks to flower. However, a successful harvest can produce 12 ounces, if managed properly.
The THC levels of this strain can reach up to 25%, but usually test around 20-22%. These unique buds produce a lemon aroma and hints of tangy, fruity tastes. The effects are long-lasting and hard-hitting with a cerebral focus. This strain is a great mood elevator and excels at treating mood disorders as well as ADD/ADHD.
After you have finished growing, an automated trimming machine can make harvesting easier too! If you are a smaller operation, CenturionPro’s Mini trimmer can help improve your bottom line and reduce your harvest time from days to hours.
For those of you who are new to growing and not yet ready for a challenge, check out our 5 easiest cannabis strains to grow.