Autoflower vs Photoperiod

Reading time: 10 minutes

When it comes to growing cannabis, choosing between Autoflower vs Photoperiod strains is one of the main things to ask yourself as a first-time grower because,  depending on what you choose, it will affect how you tend to your plants.

Not sure where to start? Get ready to join the autoflower vs photoperiod debate and learn more about both options of marijuana growing.

Big and colorful marijuana Photoperiod bud
Big and colorful marijuana bud isolated with a blurred background of a Bubble gum sativa plant.

What are Photoperiod Cannabis plants?

Photoperiod cannabis is the original option for growing marijuana. It gets its name from its response to different lighting schedules. That means it has an indefinite vegetation period until its lighting schedule changes.

Fall brings about this change when growing outdoors since there’s less daylight for your plants. Indoors, this change occurs when you adjust your grow light timer to provide 12 hours of light. Learn more about the cannabis light cycle

What are Photoperiod seeds?

Because of its indefinite vegetation period, photoperiod cannabis is the go-to plant for using advanced growing techniques. This is because they’re able to still recover from any high or low-stress conditions so long as they’re in their vegetation period. A few great examples are manifolding and mainlining to increase the number of buds on your plant and monster cropping to create clones to increase the number of your plants.

Make sure to checkout my monstor cropping guide so that you can get bigger yields!

First-time growers may get impatient by how long it takes to grow photoperiod strains. From seed to harvest, they take a lot longer compared to autoflowering plants. If you decide to use any advanced growing techniques, that will tack on another week or two.

Autoflower plant
Marijuana leaves, Cannabis on beautiful background.

What are Autoflowering Marijuana Plants?

While photoperiod cannabis is the standard strain for marijuana, autoflowers are a product of selective breeding. By breeding cannabis ruderalis with traditional marijuana strains, it gained the trait of flowering with age. The resulting offspring had higher THC levels than its ruderalis parent and a higher CBD level than the traditional marijuana strains. However, the key difference is its shortened flowering period, based on times rather than the light cycle that photoperiod strains require. Autoflowers also have a shorter grow time than photoperiod cannabis. 

However, there is a downside that might impact your decisions around photoperiod vs autoflower strains.  You should not clone autoflowers because the clone would carry on the age of the parent plant. This means that both the clone and the parent would reach their flowering period simultaneously, causing the clone to produce lower yields due to its stunted growth.

Buy Autoflowering seeds

  • Easy to grow and great for first time growers
  • Fast growing in fact most autoflower strains are ready in 9 weeks or less!
  • Choose from a collection of high-quality strains with a variety of characteristics

How Autoflowers are made?

Although impossible to clone, there is a way to create more autoflowering cannabis for your garden. You can produce autoflowering seeds through breeding if the autoflowering seeds aren’t feminized. However, even if they are, you can grow a male cannabis plant with the same autoflowering trait and breed it with your female. 

Take the guess work out by checkout out step-by-step guid to cultivating your own Blueberry Autoflower strain

If you want to create your own strain of autoflowering cannabis, you will need a ruderalis strain. Pure ruderalis seeds can be difficult to find, and the process of creating autoflowers takes time and effort. That’s why we recommend growers simply buy autoflowering seeds rather than attempt to breed their own. 

Photoperiod plant
Photoperiod plant

Autoflowers vs Photoperiod: Key differences

Autoflower vs Photoperiod: Plant size

The size of your cannabis plays an important role in the final yield. It also dictates the kind of setup you choose when growing. If you have the space for a larger plant, you will likely produce a higher yield; however, everyone doesn’t always have 8 feet of space for a marijuana plant. 

Autoflowering plants are small, generally reaching only around 2-3 feet (60-100cm) tall with short branches.

Compare that to a photoperiod strain that can grow up to 8 feet tall (100-250cm) with long branches, and you begin to understand why some people choose autoflowers. 

Autoflower vs Photoperiod: Upkeep requirements

When considering autoflower vs photoperiod cannabis, maintenance is often a key concern. Photoperiod plants have harder upkeep. They need a specific light cycle to flower. Autoflowers, on the other hand, are easy to grow. Their small size makes them simpler to maintain while staying discreet. 

Autoflower vs Photoperiod: Time from seed to harvest

Consider your harvest time when choosing between autoflowers and photoperiod plants. Photoperiod cannabis will always take longer to grow. This is especially true if you try advanced growing techniques such as topping or monster cropping. 

When it comes to the debate of photoperiod vs autoflowering time from seed to harvest, autoflowers are the clear winner. 

It takes up to  4 months to grow photoperiod plants from seed to harvest.

Autoflowers take about 2-3 months, meaning they shave off at least a month or two of harvest time.

Autoflower vs Photoperiod: Vegetative phase

The difference between autoflower vs photoperiod cannabis’s vegetative phase is a toss-up. On the one hand, photoperiod cannabis has a longer vegetation phase, and the longer phase leads to a  larger plant, which means a better yield. On the other, autoflowers have short vegetation phases which means, you’ll have a shorter wait time to harvest.

It’s up to you as a grower what you prefer to work with. Regardless of your decision, both choices offer pros and cons.

Buy quality feminized seeds

  • Every plant will produce flowers
  • No time wasted growing useless cannabis
  • Consistent heavy yields
  • Our seeds are guaranteed to germinate
  • Feminized seeds for guaranteed bud

Autoflower vs Photoperiod: Flowering phase

The difference between photoperiod and autoflowering cannabis is like night and day when it comes to their flowering phase.

The photoperiod strain’s flowering phase requires a dedicated lighting schedule.

The autoflowering strain saves you the hassle by flowering ‘automatically’ once it reaches maturity.

Unlike autoflowering plants, photoperiod strains can go back into their vegetation phase by manipulating the light schedule of flowering cannabis. This is called re-vegging or regeneration. It lets you harvest buds from the plant you re-vegged and grow the same one again.

Autoflower vs Photoperiod: THC levels

THC is the main chemical compound found in cannabis responsible for most of its effects. The percentage of THC in the plant determines how strong the effect is.

Photoperiod strains can produce strains with THC levels reaching as high as 30%. 

Autoflowering strains have a maximum of about 20% THC, although autoflowering strains with THC levels that high are still uncommon. 

Ready to take your learning offline? Download my marijuana grow bible and read it while you grow!

Grow Bible

  • Grow with my Quick Start Guide
  • Discover secrets to Big Yields
  • Avoid common grow mistakes

    Autoflower vs Photoperiod: Average yields

    Since autoflowering plants do not veg as long as photoperiod strains, they do not have the time to produce as many buds. This impacts their yield. When considering autoflowering vs photoperiod yield, think about whether you have the space to grow a bigger plant. 

    The average yield of indoor-grown cannabis is measured in grams per square meter. 

    Photoperiod strains normally yield about 650-700 gm/m².

    However, autoflowering strains may produce around 450-600 gm/m². You can increase these numbers by using growing techniques like scrogging and mainlining.

    Autoflower strain growing outdoors
    Autoflower strain growing outdoors

    Is it better to grow Autoflowers or Photoperiod strains outdoors?

    What about autoflower vs photoperiod for outdoors’ growing? Growing either outdoors has its merits and drawbacks. In the case of photoperiod strains, you will need to time your planting so that your cannabis grows with the sun. Plant your photoperiod seeds in late spring so that they can veg for all of the summer. This way, you can get a better yield from your plants once you harvest, as they’ll have had a longer vegetation phase for absorbing nutrients from the sun and the growing medium they’re planted in.

    Pros & Cons of growingPhotoperiod strains


    Better yield from your plants once you harvest
    Higher cannabinoid content than autoflowers


    Takes longer to grow
    You will need to time your planting so that your cannabis grows with the sun

    With autoflowers, they’re not as time-critical as photoperiods in the same sense. Because they don’t require a lighting schedule to reach their flowering phase, you can plant autoflower strains at any time of the year. However, that’s only if the weather in your area is favorable. Cannabis should avoid heavy rains and cold temperatures. 

    Having some bad luck growing outdoors? I’ve got you covered! Checkout my collection of outdoor grow guides

    Although not time-dependent, autoflowers do not handle environmental stress as well as photoperiod plants. A photoperiod plant can take time to get healthy, whereas an autoflower will enter its flowering stage regardless of its condition. That means, even when severely stressed, an autoflowering strain would automatically enter its flowering phase. As a grower, you must ensure your autoflower plants have ideal environments during the vegetative stage so that they make the most of their short growing period. Although they are very easy to grow, there’s also very little room for error with autoflowers, which is why advanced growers typically prefer photoperiod cannabis.

    Pros & Cons of growingAutoflower strains


    Not as time-critical as photoperiods
    Can plant autoflower strains at any time of the year


    Autoflowers do not handle
    Autoflowers yield Very Little

    After you’ve made your decision on which strain you want to grow, make sure to read up on when and how to harvest your plant, with our mini harvesting guide!

    Harvest Guide

    • Time your harvest for Perfect Taste
    • Get THC levels for a Perfect High
    • Don’t waste any Precious Bud

      FAQs on Autoflower vs Photoperiod

      Is topping autoflowers a bad idea? 

      Topping is a type of pruning that involves cutting the growing tip of the main shoot of your cannabis, which trains your plants to grow outwards rather than upwards.
      It’s generally risky to do any type of pruning to autoflowers, topping included. Your plants need time to recover after being topped, which you may not have because of how quickly autoflowers enter their flowering stage.

      What are the best autoflowering cannabis strains for beginners? 

      Autoflowering cannabis is already ideal for beginners since it takes less time for them to grow, and their small size offers growers an easier time when it comes to upkeep. However, some autoflowering strains are better than others. You can find the highest-quality autoflower seeds for beginners in our online store.

      What are the best photoperiod cannabis strains for beginners? 

      While autoflowers are typically easier to grow, photoperiod plants can also be beginner-friendly if you start with good genetics. Choose from this collection for the highest-quality photoperiod seeds with guaranteed germination. 

      Avatar for Robert Bergman

      Robert Bergman

      Robert Bergman is an Amsterdam-based marijuana grow expert who has years of experience from small grows to massive operations. His passion for growing led him to develop his own Gold Leaf strain. Now, Robert is dedicated to sharing his knowledge with the world.... [Read full bio]

      • Pinterest


      marijuana grow bible
      • Grow With My Quick Start Guide
      • Discover Secrets To Big Yields
      • Avoid Common Grow Mistakes

        2 comments on “Autoflower vs Photoperiod”

        1. Hi there,

          Thanks for the feedback, we appreciate that!

          Let us know if there’s anything we can do for you or help you with of course!
          Kind regards,

        2. Good Article not sure i totally agree ive been growing since late 90s last couple of years messing about with autos recently gorilla glue skittles both set away ay same time 3weeks in skittles begins to flower finishes around 70 days 6 weeks in gorilla glue just starts to flower and finishes around 15 weeks so iam not sold on autos sensi skunk veg for 3 weeks or lets say21 23 days flowers around 50 days not much more faster than gorilla glue by 2 weeks

        3. Hi Brent,

          Thanks for your comment! Autoflowers do not require a 12/12 schedule to trigger flowering. They can be grown under 16/8 and upwards! Some people like to use longer light cycles on them to increase the speed of growing. Though I would definitely recommend giving them a decent amount of dark hours to avoid stressing the plants.
          I hope this helps!
          Kind regards,