5 Strongest Autoflower Strains to Grow for 2021!! >>


The most powerful autoflowering cannabis strains have improved dramatically over the years and are now more potent than ever. They are popular with breeders because of their short stature. In addition, they don’t depend on the perfect amounts of changing light and darkness to bloom. They also have shorter lifetimes.

Strong auto cannabis strain

If you are planning on growing autoflowers, the best autoflowers for indoor growing as well as the strongest outdoor autoflower cannabis strains are worth considering. Growers enjoy all the benefits of an autoflower without sacrificing THC levels.

What are autoflower strains?

Autoflowering strains start to bloom at a certain age rather than reacting to the changing seasons (or more precisely, the changing light).

Photoperiod plants, on the other hand, only go from their vegetative stage to the flowering stage when the hours of daylight (whether artificial light or natural sunlight) have decreased below a certain point and the hours of uninterrupted darkness have risen to a certain point.

Autoflowers generally have a shorter life cycle than other types of cannabis. Shorter life cycles can be useful for people with a shorter growing season, e.g. B. in colder climates. It can also be useful for those with longer growing seasons who want to enjoy two harvests in the warmer months. This is only possible with autoflowers as most photoperiod plants are not ready in midsummer.

Do you want to grow strong autoflowering strains? Download my free Grow Bible to see how!

Autoflowers are also popular because of their small size. It makes it easier to grow indoors and is less of a problem than larger cannabis plants. Indoor growers don’t need to prune or train them like larger plants, and both indoor and outdoor growers will find that autoflowers are easier to grow discreetly.

Autoflowers are also highly resistant to pests, which gives those looking to grow these sturdy plants a certain ease. The same applies to the resistance to difficult weather conditions.

Autoflowers are a combination of the cannabis ruderalis plant with cannabis indica or cannabis sativa. It got a bad rap initially for not having as much THC as other weed options. Today, however, autoflower strains have improved a lot. Gone are the days when autoflowers meant weak marijuana plants!

How do marijuana growers measure THC levels?

Measuring the THC content of a strain, known as a “potency test”, is an integral part of the work of the breeders. Generally, samples are sent to a laboratory for testing. All labs don’t use the same process, but these days the tests are very accurate.

The majority of efficacy tests use “high performance liquid chromatography” or HPLC. This method uses a liquid that contains cannabis and pressure to determine THC levels. Another technique called “gas chromatography” or GC is sometimes used. It vaporizes the cannabis without decomposing the product and then reads off the purity.

These tests, usually performed by an outside laboratory rather than on-site by cultivators, allow breeders to see what their breeding efforts have achieved. These tests also help breeders determine which strains are most potent and which must therefore be combined with cannabis ruderalis to produce autoflowers that are also high in THC.

Because of this collaborative effort between breeders and those who scientifically measure THC levels, we are at a point today where the potency of a strain that was previously known to be relatively weak is now very popular with all types of marijuana users is.

How to Grow Strong Autoflower Strains

Growing potent autoflowers isn’t just about breeding and genetics, it’s also about using certain techniques to increase the potency of autoflower buds. Here are some things to keep in mind when trying to grow some of the most potent outdoor autoflower THC strains.

Plant health

If you want your marijuana plants (whether autoflower or otherwise) to be as budding as possible, pay close attention to their general health from the time you sprout them. Research best growing techniques to prepare for your growth and try them out once you have your seeds.

Lighting conditions

The duration, intensity, and type of lighting you use can make a huge difference in how much THC your buds have. Plants with lots of light generally get bigger and stronger – and that includes bigger, juicier buds. Changing your lighting to LED lighting is known to help maximize THC levels.

Harvest and healing

While it’s easy to forget the stages of your plants’ life cycle, harvesting and curing can make a massive difference in the THC levels of your buds. Plan the harvest properly so that you get as much THC in the buds as possible, and then heal the buds properly so the supply lasts and the THC doesn’t deteriorate.

Know when to harvest your plants for maximum THC with my free mini harvesting guide.


Genetics are one of the most important determinants of the growth of high THC autoflowers. Well worth paying a little more for good genetics as they will decide what the potential for your buds’ THC levels is. Without good genetics, all other growing efforts could be wasted. Let’s take a look at some of the most potent autoflower strains.

Top 5 strongest autoflower strains

Zkittlez car

Zkittle’s Auto is known as the most potent indica autoflowering strain. It’s also one of the fastest, and it takes around two months to grow. Zkittles has a THC potency of 23%, which makes it a very potent strain.

True to its name, Zkittle’s car brings an explosion of fruit and sweetness to the user. In typical indica fashion, this strain will relax your body until you are comfortable and relaxed. It makes for a good end to the smoke day.

Buy Zkittlez Auto Seeds

When growing zkittles, keep in mind that it has a strong odor. This may not matter if you are growing outdoors, but indoor growers should be aware of this.

Gorilla glue car

This hybrid strain also has high levels of THC, reaching 24% at times. This definitely makes it worth the money and effort for the grower. In fact, those numbers make it one of the most potent autoflowering cannabis strains out there.

Gorilla Glue Auto takes its name from the resin that covers its buds. This resin looks whitish and is similar to glue. The plant and its buds do not smell of glue, however. Instead, the scent resembles that of pine in a pleasant, earthy way. It is an award-winning variety that is loved by many breeders.

Buy Gorilla Glue Auto

The harvest is quite high and the flowering time is quite short, although not the absolute shortest autoflower strain. Usually you can harvest after 9 to 10 weeks.

Banana Kush Auto

Banana Kush Autoflower is a slightly indica-dominant hybrid. This strain has a whopping 27% THC, but basically no CBD to speak of. It blooms quickly and lasts around 8 weeks in total. As the name suggests, Banana Kush Autoflower has a sweet banana flavor and aroma. This makes users feel happy, relaxed, and uplifted.

These compact plants do well for smaller spaces and are best grown indoors, unless you live in an environment with warm temperatures (between 68 and 80 degrees Fahrenheit is ideal). Since they are compact, the humidity should only be 40% and not higher.

Buy Banana Kush Auto

Gold leaf car

Gold Leaf Autoflower is one of our signature strains and it’s easy to see why. First of all, it is easy for everyone, even beginners, to grow this strain. The plants are compact and grow happily indoors or outdoors. The flowering time is only 8 weeks. The THC levels are beginner-friendly too, strong, but not too strong at 21%.

The aroma and taste of this strain are loved by many, which has to do with its earthy, sweet, spicy tones. It’s an indica-dominant hybrid (60% / 40%) that leaves users uplifted, euphoric and relaxed.

Buy gold leaf car

Bruce Banner car

Bruce Banner Autoflower is a Sativa dominant (60%) hybrid strain. The THC levels are high at 25%, which is significant given the short growing time (8 weeks). These plants are quite large so make sure you have enough space for them before you buy the seeds.

Its pungent, earthy, diesel aroma isn’t for everyone, but a lot of people really like it. The users are happy, relaxed, and euphoric. This potent autoflower won an award at the Cannabis Cup, which is no surprise to those who have grown and / or smoked it!

Buy Bruce Banner Auto

FAQs on the strongest autoflower strains

How much light can you give your autoflowering plant?

Give them as much light as you want! Since they don’t depend on light changes during their life cycle, a ton of light won’t disrupt their growth or flowering phase.

Are Autoflowers High in CBD?

The strains listed in this article are focused on THC and don’t have a lot of CBD (if any). However, many autoflower strains are high in CBD, making them ideal for those looking for an easy-growing marijuana plant. Find high strains of CBD in our shop.

Do autoflowers have lower yields?

Because autoflowers are smaller and have a shorter life cycle, their yields are generally lower than photoperiod marijuana plants. However, you can maximize their yields and potency with expert growing techniques as outlined in this article.

All you need to do is practice and learn to grow marijuana like a pro. Let our blog help with all of your growing questions.

What are your favorite autoflower strains? Tell us in the comments below!

Have fun waxing!


I Love Growing Marijuana Founder Robert Bergman is a marijuana growing expert who loves to share his knowledge with the world. He combines years of experience, from small extensions to massive operations, with a passion for growing. His articles include tutorials on growth … [read more]



Robert Dunfee