If you’re looking for a challenge in growing cannabis, there are some strains out there with fantastic medicinal benefits and an amazing high which are considered much harder than the average plant to grow. Some are even considered very difficult for the grower, so they aren’t popular in commercial farms especially because of the long growing periods, complex feeding requirements, and low yields. Landrace sativas are particularly notorious for being difficult to grow because of unusually long flowering times.
Many strains that are regarded as difficult to grow are landrace strains. “Landrace” refers to feral strains that have long grown in one geographic location without hybridization. These varieties often have varying and specific needs, making them some of the more complicated plants to grow. However, plenty of modern hybrids can prove to be challenging as well.
1 Dr. Grinspoon
This landrace sativa strain is named after longtime cannabis advocate and professor at Harvard, Dr. Grinspoon. The genetics are held by Barney’s Farm in Amsterdam and are well known amongst connoisseurs for its cerebral effects and quality of flavor. It is also known for its strange bud structure. Dr. Grinspoon is difficult to grow because of this bud structure. It can take ages for it to flower and for the airy buds to develop any weight. The stems and buds are brittle, but the end product is something you will rarely ever see.
Headband is well-loved for delivering a long-lasting relaxing high. This strain is called such because users tend to feel some pressure around the crown of their head after smoking it, although it’s a great strain medicinally and has a high THC content. Headband prefers to grow in warm, sunny climates but during rain it needs to be sheltered especially if you’re already in a wet climate. Growers need to pay close attention to the humidity levels and make sure that there is no frost. It can take up to 10 weeks for Headband to flower in the best conditions, and can yield an average of 18 ounces per square meter. This strain should be harvested in the middle of October.
3 Malawi Gold
Malawi Gold is perhaps the rarest cannabis strain in the world. This landrace sativa is fabled to produce colas as long as two feet (60 cm), but it has one of the longest flowering times in the world. This equatorial beauty takes 84 to 120 days to flower. Growing this bud outside of its native environment is especially difficult. This strain is best-suited to a tropical climate and is not appropriate for cool, northern climates. If trying to grow this lady outside of a tropical region, it performs best indoors or in a temperature controlled greenhouse. If growing indoors, this strain needs some space. However, this plant thrives outside when grown in the right environment. It also prefers high-quality organic soil as a growing medium.
ACDC tends to be light sensitive and likes a moderate amount of nutrients, so this delicate lady needs to be grown with an expert hand and lots of care. Rumor has it, ACDC particularly loves calcium and magnesium and this whispy plant will need some propping up during flowering. Fortunately, this extra attention reaps great rewards. This strain can produce up to 20 percent CBD, making it a great choice for making hemp extracts for CBD therapies.
Thai is a landrace sativa representing numerous strains that were originally grown in Thailand. In fact, many of the original Thai strains can no longer be found today. The Thai strain enjoys hot outdoor environment and can grow quite tall. Growers need to be meticulous with pruning, topping, and training this strain. Thai strains grow best with organic soil and compost, so to successfully grow this plant you’ll need a godo supply of quality natural food. Flowering time for Thai strains usually take 65 to 98 days.
6 Jack Herer
Jack Herer is a legendary strain named after a legendary cannabis activist. However, it’s been known as one of the most difficult cannabis strains to successfully grow. Flowering time takes 70-80 days but it will be well worth your effort. Jack Herer grows best in dry Mediterranean climates, and it can produce up to 18 ounces of bud in each plant. Despite a long flowering time, Jack Herer is resistant to a number of diseases so if you’re willing to wait, then you should try growing this strain.
7 Colombian Gold
Colombian Gold is a landrace sativa hailing from the Santa Marta mountains of Colombia. Made famous over the century as a high-quality cannabis export to the United States, it made a comeback when its genetics were used in the creation of Skunk #1. What makes Colombian Gold a difficult strain to grow is its large stature and long flowering periods. To produce this strain indoors, you must be on top of your pruning game; its growth takes off and will quickly overrun your space. The lengthy flowering cycle also increases the chance of error, but if you can bridle this strain, you will be rewarded with a classic quality landrace strain with an exceptional high that electrifies the senses.
8 Chocolate Thai
Chocolate Thai is a nostalgic strain commonly associated with the famed Thai sticks of the 1970s and 80s. Cannabis from this region of the world has always been celebrated and cherished for its unique cerebral effects. The difficulty of this strain can be attributed to its lengthy flowering cycle. Similar to all southeast Asian landrace strains, flowering may take up to 14 weeks. If you have the space, time, and skill to produce a decently yielding Chocolate Thai or any other southeast Asian landrace strain, you have something to be very proud of and will be sure to impress anyone who fondly remembers days spent with Thai sticks.
Trainwreck is excellent for anxiety, pain, PTSD, and ADD but can sometimes be considered difficult to grow. It’s one of the most dank strains out there and will definitely have the entire room smelling like cedar and pine. Trainwreck requires trimming to avoid it spreading far out although they grow tall and with thick stems. This strain grows pretty prominent resin. If you want to grow Trainwreck well, it will have to be indoors because the outdoors will make it extremely difficult. If you do grow this strain well, you will be rewarded with a generous harvest of up to 25 ounces per plant. The best harvesting times for this strain is late October to early November.
Blueberry has a long and distinguished heritage dating back to the late 1970s when it was first created in the Netherlands. The plants grow to about one metre and display a thick, bushy shape. The large calyxes have tight buds which are dusted with a white coating of crystals when mature. This is a potent weed with a THC content of around 20 percent. Blueberry seeds are definitely best used for indoor growth, although, you may have some success outdoors if you live somewhere with a subtropical or tropical climate. Blueberry is listed in the cannabis grow Bible as one of the hardest to grow to maturity. This old-school plant is a good choice for the skilled cultivator who will be rewarded with the highly potent Blueberry weed and its delightful taste.