Photoperiod vs. Autoflowering Cannabis Strains: What’s the Difference?

The increasing popularity of cannabis cultivation has led growers to explore new techniques and strains to optimize their yields.  Among the many options and approaches available, leveraging photoperiod vs. autoflowering cannabis strains stand out as two of the most common, with each catering to different growing preferences and conditions.  Understanding the differences between these strains is important for beginners and veterans alike, as each offers different benefits depending on your goals.

What Are Photoperiod Cannabis Strains?

Photoperiod cannabis strains are the more traditional variants that rely on changes in light cycles to transition from a vegetative to a flowering stage.

In nature and for outdoor growers, these cannabis plants begin to flower in the fall as daylight hours decrease.  Meanwhile, indoor growers must manipulate light schedules to achieve the same effect.  This usually means providing full spectrum light for 18-24 hours a day during the vegetative phase, and tapering back to 12 hours of light and 12 hours of darkness when flowering is desired.

Photoperiod strains offer several advantages to growers:

• Higher Yields: Due to their extended vegetative phase, they often produce larger yields than autoflowering varieties.
• Cloning Potential: Growers can replicate plants with desirable traits through cloning.
• Strain Variety: A wide variety of well-known strains, such as classics like Northern Lights and OG Kush, are available in photoperiod form – each offering unique flavor profiles and effects.

As you can imagine, a significant benefit is the control over growth that photoperiod strains offer.  Growers can extend the vegetative phase to achieve their desired plant size before initiating flowering.

This control also allows for various training techniques to maximize light exposure and yield. For instance, topping involves removing the main stem’s growth tip to encourage bushier growth, while low-stress training (LST) uses gentle bending of branches to create a more expansive canopy.  Seasoned growers may even use the Screen of Green (SCROG) method, which utilizes a mesh screen to create an even canopy, further improving light penetration.

While the benefits are many, there is no perfect strain.  Photoperiod strains are time-intensive, requiring longer cultivation periods due to their dependency on light schedules.  This also means a more complex light management schedule – albeit this is something made much easier with modern smart LED setups.   A strict schedule is important not just to encourage growth, but to ensure minimal stress and chances of hermaphroditism.

Then, there are vulnerabilities to their environment, with fluctuations in temperature and humidity causing stress and potentially resulting in a reduced yield.

Finally, when grown outdoors, photoperiod cannabis typically has only one harvest per year in most climates due to the duration required.

What Are Autoflowering Cannabis Strains?

On the other hand, we have autoflowering strains.  Unlike the photoperiod strains, which are light-dependent, these are genetically engineered to flower based on age.  Interestingly, their lineage can be traced to Cannabis ruderalis, a subspecies that, over time, adapted to the short, cool growing seasons of regions like Central Asia and Russia.

Autoflowers typically begin flowering 2-4 weeks after germination, regardless of light conditions.

The primary advantages of autoflowering strains include:

• Fast Growth Cycle: They mature quickly, often completing their lifecycle within 8-12 weeks.
• Ease of Cultivation: Less demanding in terms of light management, making them ideal for beginners.
• Compact Size: Their smaller size makes them suitable for indoor grows or limited spaces.

Furthermore, their ruderalis heritage provides resilient genetics, making them more resistant to pests, diseases, and environmental fluctuations.  One of the most significant benefits for outdoor growers is their versatility.  Autoflowers can potentially yield multiple harvests in a single outdoor growing season due to their rapid growth cycle.  This is especially true for those that reside in warmer regions with extended summers.

Unsurprisingly, the expedited growth cycle of autoflowering strains often results in lower yields compared to photoperiod strains.  Their quick growth also limits the effectiveness of the aforementioned training techniques.

Additionally, autoflowers are not effectively clonable, as any clone attempted would inherit the same genetic clock as the parent plant.  This in turn means that it will begin flowering before it is ready to support the process.

Finally, while potency was a concern in the past, advancements in breeding have significantly improved their cannabinoid and terpene profiles.

Quick Comparison

Choosing the Right Strain for Your Needs

Selecting between photoperiod and autoflowering strains depends mainly on your goals, experience level, and growing environment.

Consider photoperiod strains if:

• You have the time and resources to manage light cycles.
• Higher yields and a wider strain variety are priorities.
• You want to clone plants or experiment with advanced training techniques.

Consider autoflowering strains if:

• You are new to cannabis cultivation and want a less demanding option.
• You have limited time or space.
• A faster turnaround for harvesting is desired.
• You are growing outdoors and want multiple harvests in a single season.

Hybrid Growing Techniques

Some growers combine the benefits of both types. For example, starting autoflowering seeds a few weeks after photoperiod plants allows the autoflowers to be harvested while the photoperiod plants are still in their vegetative stage or early flowering, ensuring a continuous supply.

Final Thoughts

Photoperiod and autoflowering cannabis strains each bring with them unique pros and cons.  By understanding their differences, you can appropriately choose between the control and variety of photoperiod strains or the convenience and speed of auto flowers; successful cultivation lies in adapting your techniques to suit the chosen strain’s characteristics.  Or, have fun with it and simply have fun experimenting with each to find the perfect option for you!