Medically Reviewed by
Jason Crawford

Article Last Updated on January 6, 2023

If you are looking to become a cannabis grower and grow your own marijuana, you might have come across the term autoflowering plants. So, before you go to the seed bank and buy the seeds to grow your own cannabis, you should inform yourself and decide if you want to use autoflowering or photoperiod strains.

Even if you are still deciding which cannabis plants you’d like to grow, you should learn the difference between autoflowering and photoperiod marijuana plants. So, let’s dive further into the pros and cons of growing autoflowering compared to photoperiod strains, how you can grow them, and we’ll also list the most popular autoflowering cannabis.

What Is Autoflowering Cannabis?

Autoflowering cannabis emerged as a result of adaptation to the environmental conditions with the Cannabis Ruderalis strain. These cannabis Ruderalis plants are native to Central and Eastern Europe, and Russia. 

What are referred to as autoflowering cannabis plants are plants that automatically switch from the vegetative state to the flowering stage without needing closely timed hours of light and dark

Compared to photoperiod plants, which require a shift in the light cycle to initiate flowering, autoflowering cannabis strains don’t rely on external cues to trigger flowering. Generally, cannabis growers either opt for a 16/8 cycle or a 24-hour cycle when it comes to the autoflowering plants.

Autoflowering strains are generally lower in THC, although you could find both autoflowering and photoperiod plants with the same levels of THC and CBD cannabinoids. Moreover, autoflowering weed produces a lower yield, since small plants cannot sustain bigger and denser buds.

How Do Autoflowering Seeds Grow?

It generally takes a shorter amount of time to grow autoflowering plants, compared to photoperiod plants, but they also need to go through the 3 important stages of growth:

  • Germination stage;
  • Vegetative stage;
  • Flowering stage.

In order to cultivate autoflowering cannabis, you’d need to follow these four steps.

Training Period

This period takes around 2 weeks and it starts with topping your plant in order to increase the yield and the size of the buds. It’s important that you don’t prune the cannabis leaves immediately after the flowering phase since you may risk inhibiting growth.

Growing Period

During this period, it would be ideal if you keep your autoflowering cannabis plants under a specific amount of light. The most optimal light exposure would be about 18-20 hours per day, although you can do less than that. Just make sure that you never go under 4 hours of light per day.

Feeding Plants

Cannabis plants that are autoflowering need minimal upkeep as to feeding. Since autoflowering cannabis grows smaller in size, it needs less nutrients compared to photoperiod cannabis, and you could find all the nutrients in specially formulated soils.


These types of strains should be harvested gradually since they can’t develop a canopy, and the buds grow lower compared to photoperiod plants.

Autoflowering Cannabis Strains vs Feminized Strains

When browsing for cannabis seeds, you may have heard the term “feminized strains”. This can refer to both autoflowering and photoperiod strains since they can both be feminized. The modification is done to the strain in order to produce exclusively female plants. Some cultivators decide to go this way since feminized strains may produce higher yields compared to regular seeds.

Pros of Autoflower Cannabis Seeds

Faster Life Cycle

The first advantage of these autoflowering cannabis varieties is that they have a short life cycle that results in faster-yielding crops. The entire growth cycle is about 7-10 weeks which is generally the amount of time it would take photoperiod strains to finish flowering alone. 

For this reason, cannabis cultivators often merge the Ruderalis genetics of the autoflowers with other strains so they have a faster turnover with lots of perpetual indoor harvests per year. And in order to maximize yield, they plant multiple autoflowers close to each other so that they converge into one canopy.

Discretion When Cultivating

Even in these legalization times, a lot of growers opt for clandestine cultivation of marijuana and these autoflowering varieties are perfect for this method. The typical height varies between 60-100 cm, which makes them perfect for indoor growing and also dismantling the whole operation relatively fast. Growers often use low-stress training so as to keep the plants small and cultivate them inconspicuously.

Simple Light Schedules

Autoflower growers have it easy when they decide to cultivate these types of strains. They generally have a light schedule of 18-20 hours on and 4-6 hours off during the whole life cycle. When using this schedule, growers get to save energy as well as provide the plants with an adequate amount of light. 

Moreover, compared to photoperiod strains, they don’t require a change in the light schedule in order to reach the flowering stage. Some growers even go as far as implementing a schedule of 12 to 12 hours, although this way the crops yield less. 

Resilient Genetics

As previously mentioned, the cannabis Ruderalis is an extremely resilient plant which has adapted with extreme temperatures and harsh weather. The subspecies’ name “ruderalis” comes from the Latin word  “rudus” which means rubble. These types of cannabis plants are rarely affected by pest infestations and mould, and are well-suited for beginner growers since they are fairly easy to cultivate.

Fewer Nutrients Needed

Since autoflowers have a speedy growth-rate, they can thrive in all kinds of soil and they don’t require a lot of fertilizer compared to their photoperiod counterparts.

Higher CBD Levels

These strains are higher in CBD and are a go-to option for most medicinal users since the cannabinoid offers pain-relieving effects. Many famous hybrids are infused with the Cannabis Ruderalis genetics in order to increase the CBD levels.

Cons of Autoflower Seeds

Lower Yield

The small size of the autoflowers results in smaller harvests compared to photoperiod cannabis which produce more buds. Generally autoflowers don’t exceed 1 m in height, and they bloom less buds as a result of their short flowering time and general lifespan.

Lighting Cost

While some growers give their autoflowers a 24/7 hour light cycle, this is more on the expensive side. While productive photoperiod strains have a schedule of 12 hours of light and 12 hours of darkness, some growers find it economically inefficient to invest the same amount of money into autoflowering plants that produce lower yields.

Lower THC Content

Compared to their photoperiod counterparts, autoflowers generally have lower THC levels. However, nowadays, newer strains are cultivated which modify the Ruderalis genetics and result in a high-THC content, that rivals even photoperiod cannabis strains.

No Time for Recovery

Since they grow very rapidly, there’s generally no time for the plant to recover if you cut a branch too deep, or you damage a bud site. On the other hand, photoperiod plants can be pruned, trained, and modified to the growers’ taste since they can be put into veg mode and recover. 

Popular Autoflower Cannabis Strains

Some of the more popular autoflowering strains include:

  • Northern Light Automatic (Indica dominant strain with a bit of Sativa that’s abundant in CBD);
  • Amnesia Haze Automatic (Nearly entirely cannabis Sativa with a higher level of THC);
  • White Widow Automatic (Cannabis Indica-Dominant with greater yields in a short amount of time).

What’s the Verdict on Autoflowering Marijuana Strains?

Indoor growers could particularly benefit from cultivating these high-yielding autoflowering plants with explosive vegetative growth. While the autoflowering Cannabis Ruderalis strains aren’t ideal for recreational users since they produce yields that are generally low in THC, they are beneficial for consumers of medical marijuana due to their high CBD levels.

Today, growers modify the autoflowering genetics in order to cultivate Ruderalis plants with higher THC levels by fusing them with Indica and Sativa strains that contain larger THC concentrations. 

To sum it up, whether you decide to buy photoperiod or autoflowering cannabis seeds will depend on your preferred yield quantities, the time you would like the life cycle to be, as well as your preference of THC or CBD levels of your crops.

A passionate advocate for the benefits of cannabis. Fraser Horton, who has a background in botany and a strong love of nature, has spent years researching how cannabis affects the body and mind. He established Leaf Nation in 2020, where he has devoted himself to educating people about the legalisation of marijuana and its safe and responsible use. Fraser is committed to highlighting cannabis’ potential for improving wellness and working to dispel the stigma associated with its use.


The information presented on this page is provided as a public service to aid in education and is derived from sources believed to be reliable. Readers are responsible for making their own assessment of the topics discussed here. In no event shall Leaf Nation be held reliable for any injury, loss or damage that could happen if using or abusing drugs.