The reason legal cannabis costs so much at the dispensary is the amount of time that goes into cultivating and processing the plant for consumers. Consider every duty, start to finish, from seed to trimming and cure. With most strains needing 10-12 weeks for harvest, it’s no wonder a new strain might take 4 months, at the least, before it can legally hit the shelves. This is not the case with all strains, however. When it comes to the fastest strains to grow, most enthusiasts will tell you to work with autoflower strains. Autoflower strains originated from Northern latitudes with short growing seasons. These plants were a sub-species of cannabis called Ruderalis. Most commonly found in Russia and Siberia, the plants could be exposed to up to nineteen hours of light in June. They adapted to grow straight through the never ending sun rays, from seed to flower, in eight to ten weeks.

The top of a cannabis cola that has sunlight shining down on it. Autoflower strains can grow light periods outside of the standard 12/12. Photo credit: Shutterstock
To put it into perspective, regular cannabis strains need sixteen hours of light and eight hours of darkness while vegetating, then twelve hours of light and twelve hours of darkness to produce buds once they are in bloom. The average life cycle of cannabis can be anywhere from four to eight months from start to finish. But what if six-week flower times could be achieved?  Are there 45 day flower strains? Keep reading to find out the fastest strains to grow.

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Why Choose Autoflower?

The shortest answer is speed and resiliency. But how did that happen?

A green cannabis plant with thin, narrow leaves Ruderalis is known for surviving in harsh environments. Photo credit: Shutterstock
There are three basic subgroups of cannabis: sativa, indica, and ruderalis. Each of these originated from different parts of the world and adapted for best growth in those climates. Ruderalis, the toughest of the three, grew in the northern hemispheres where colder temperatures reign supreme. These areas didn’t allow much sunlight, if any. So, what did the plants do? They finished faster in the few months of sunlight they had. Autoflower strains automatically start flowering right around 2-4 weeks, depending on the strain. With less time for production, they tend to be shorter and bushier. Their THC content levels, though not always, tend to be on the lower side, 20% and under. The yield can be smaller, but all in all you have a quicker turnaround time to get started on the next harvest. Before discussing specific strains, the growing techniques you use can affect yield within the shorter grow period. The best options to use are low-stress training and topping colas. Some growers believe that growing in a deep water culture box can also improve final yield. These ideas will not, however, improve the growing time itself.  Let’s dig into the fastest strains. While autoflower strains are quite literally the fastest on the market, some growers prefer standard growing periods, so we have included them into our top recommended strains.

The Fastest Strains to Grow  

Fast Eddy

From the good people at Royal Queen Seeds, this 6 week flower strain is roughly 50% sativa, 40% indica and 10% ruderalis. Strainwise, this is a cross of Cheese, Ruderalis, and Juanita la Lagrimosa, a legendary CBD strain that comes in at 22% total cannabinoids. The flowering time, aka the reason you’re here, is about 6-7 weeks. Then, you can chop her down and cure it up. One takeaway about Fast Eddy, along with many fastest strains to grow, is the output. The THC potency rarely tops 10% but the CBD is averaging around 15%. The almost 1:1 THC to CBD ratio makes this strain ideal for medical patients seeking relief versus the high. This will smoke with the full entourage effect.

Easy Bud

Easy Bud is a great place for newbies to begin. Although the genetics are mostly unknown, there are a lot of Ruderalis genetics in its DNA, therefore it is resilient. Growers can expect to see these short, bushy plants flowering in as little as 6 weeks. On average, it can yield about 100 grams with THC content anywhere from 10-17%. 


Green cannabis nugget that has orange and yellow hairs popping out! Gigabud is a strong indica that grows on the shorter side. Photo credit: Shutterstock
From the team at G13Labs, Gigabud is described as a heavy indica. If grown outdoors, this plant is said to finish flowering in as little as 5-6 weeks. It harvests best in late September to October at this speed but will take even longer if grown indoors. Gigabud tests anywhere from 15-19% THC and might just be that anxiety-relieving, knockout high you’ve been seeking.

Royal Cheese

With a flowering time of only 7-8 weeks, the folks at Royal Queen Seeds have outdone themselves with Royal Cheese. This strain is a cross between Old School Skunk and Afghani. Although this strain can be harvested sooner, the breeder claims it can go longer if one is seeking more potency. The classic cheese aroma is strong and would highly recommend carbon filters if you are growing this indoors.

Quick One

Combining genetics from an OG, Lowryder, Quick One ranks as one of the fastest autoflower strains available. It is engineered with around 30% ruderalis genetics and therefore incredibly resilient.  Flowering time takes about 8 weeks and can yield over 300 grams if grown indoors. Quick One runs about 60cm tall and comes in at about 10-13% THC content. Like the many other ruderalis plants, there is less time for THC production. Regardless, consumers can find medicinal relief any time of day with this strain in their cupboard.

Blueberry Muffin

Presenting the next 6-7 week flowering strain is Blueberry Muffin. Crossing Blueberry and Afghani, the talented growers of Humboldt Seed Co. created an indica-dominant barn burner. Due to the indica-dominant Blueberry cross, this one is best smoked near the end of your day.  Although the THC content is only 19%, the terpenes in Blueberry Muffin will do their job. Users will feel a cerebral relaxation from the tips of their toes to the end of their nose. The terpene, Myrcene, is responsible for this feeling of sedation. The best place to grow this 6 week flower strain is indoors. 

Early Girl

The name says it all. This girl finishes her harvest earlier than most strains out there. Early Girl finishes flowering at around the 7 week mark. The buds will be very sticky with THC content between 12-20%. This strain is said to include less paranoia effects thanks to its indica dominant genetics, which is great for those who fly off the handle with certain sativa strains.

Banana Kush

A dark green bud with red hairs on it Banana Kush can grow extremely tall, so topping is encouraged. Photo credit: Shutterstock
What better way to end our list than with something fruity?  Banana Kush is an indica-dominant hybrid that does best indoors and can yield flowers in as little as 47-60 days. When growers let this strain grow big outside, it can grow as tall as 16 feet. The THC percentage typically reels in around 18-20%. Although this strain can be grown fairly quickly, it is not the easiest strain for beginners.

Further Advice for Growers

Consider your grow environment  before you decide which plants to use. Here in Denver, indoor grows are best for the arid climate. Take these factors into mind when choosing which strain to grow. Some of them might do better indoors and vice versa, especially when it comes to dealing with the fastest strains to grow like autoflowers.