Grow GuidePhotoperiod vs. Autoflower Cannabis: Which Seed Type Should You Choose?
Oct
Cannabis genetics offer a wide range of trait variations. Among them, flowering patterns stand out. This article explores the difference between autoflowering and photoperiod cannabis seeds. We will also examine how these two types of cannabis seeds impact your grow and how to select the best fit for you.
Let us dive right in.
Photoperiod Cannabis
At first, cannabis plants were categorized as either sativa or Indica. These two groups came from their genetic adaptations to their original growing regions. However, they all shared one common trait: the timing of their flowering.
In both species, the plants flipped as fall rolled in, characterized by the shorter sunlight hours. These shorter days served as a trigger, signaling to them that it was time to stop growing and start blooming, so they could finish before winter hit them hard.
This trait defines photoperiod cannabis plants. Growers soon discovered they could control it indoors. By extending the dark hours, they mimicked autumn and pushed the plants to flower.
Autoflower Cannabis
Enter cannabis ruderalis, a new cannabis species that was first scientifically described by D. E. Janischewsky in 1924. The Russian botanist observed a population of wild-growing cannabis plants that were clearly different from the better-known Cannabis sativa and Cannabis indica.
Ruderalis plants evolved in the harsh winter regions of Central and Eastern Europe and Russia. Instead of relying on seasonal light changes, they learned to flower by age to match the short summers that translated to short growing seasons.
The ruderalis discovery had little impact on the cannabis world at first. Most enthusiasts dismissed it as a type of low-quality hemp due to its tiny buds with poor potency and a smell that struggled to linger.
It wasn’t until breeders began crossing ruderalis with photoperiod strains that the modern autoflowering cannabis seeds emerged. These strains combine the potency of photoperiods with the autoflowering capabilities of ruderalis.
How to Tell the Two Apart—and Why It Matters
As we have already seen, the primary difference between autoflower and photoperiod seeds lies in their flowering patterns. But that one detail causes a ripple effect that touches every part of your grow.
1. Flowering Time & Harvest Timelines
The average seed-to-harvest autoflower timeline ranges between 8 and 10 weeks. There is no waiting for signals or seasonal cues because once the plant reaches maturity, it enters its budding stage.
Photoperiod cannabis flowering time, on the other hand, depends on you. Indoors, you’ll need to switch the light cycle from 18/6 to 12/12 to trigger it. Outdoors, it waits until autumn, when the days get shorter and the dark hours longer. Flowering alone can take 8–12 weeks, in addition to the vegetative phase.
Do autoflowers grow faster than photoperiod strains? Well, the autoflower cannabis growth cycle wins. However, if you want more control over the timing and manner of your plant’s transition, photoperiod cannabis seeds give you that dial.
2. Indoors vs Outdoors
Photoperiod outdoor cannabis plants offer their best in regions with clear seasonal light changes. Think southern climates with long summers and defined autumns. But they demand commitment—plants can grow huge, and harvests can stretch into late fall.
Autoflowering cannabis seeds, however, are ideal for short growing seasons. They flower no matter what. That makes them suitable for northern growers or those who want multiple outdoor harvests per year.
Want to grow indoors? Both types can work, but autoflowers demand fewer adjustments. You can even grow autoflower and photoperiod plants in the same tent. Just be smart with your light schedules.
3. Growing Experience
Autoflower vs photoperiod for beginners is a common question—and here’s the truth.
Are you brand new to the grow room? Go auto.
Autos are forgiving. You don’t need to manage light cycles, worry about light leaks, or stress about flipping at the right time. You just water, feed, and watch them go. Plus, with growing autoflowering cannabis seeds indoors, even a basic setup can get you results.
Photoperiod cannabis requires a bit more finesse. You’ll be responsible for triggering bloom, monitoring stress levels, and occasionally performing plant training techniques. If you’re hands-on and love the process, it’s a great learning curve.
4. Growing Requirements
Photoperiod cannabis needs more than just soil and water. You’ll need:
- Timers for light control
- A grow space that seals light leaks
- A setup that mimics seasonality indoors
You can’t go without these requirements, as the stress from longer light exposures during flowering or light leaks can lead to hermaphroditism in cannabis plants.
When a plant “hermies,” it starts to produce pollen. This pollen can then pollinate the plant itself and any other female plants in the grow room. The result is a harvest full of seeds, which drastically reduces the potency and yield size of the final product.
Meanwhile, an autoflowering cannabis seed light schedule can stay at 18/6 or even 20/4 throughout the grow. No dark periods required. That means less fuss, especially if you’re just starting or working with a basic indoor kit.
5. Yields (Quantity)
The average yield for photoperiod cannabis plants is typically higher. These plants grow bigger, veg longer, and produce fatter colas. Indoors or out, they can deliver monster harvests when the conditions are right.
Autoflower cannabis plants tend to be smaller. But they make up for it in speed. You can run multiple crops per season. And modern genetics is pushing auto yields closer to photoperiod levels.
While a single photoperiod might outyield a single auto in a single grow, a well-nurtured auto run can rival or surpass it in yearly grams per square meter.
Pro Grow Tip : To maximize yields, use plant training techniques like LST or Topping to create an even canopy. This maximizes light distribution encouraging more bud sites.
6. Bud Potency (Terpenes and Cannabinoids)
We have already seen how old-school cannabis autoflowering plants had weak THC and muted flavours. However, those days have mostly passed. Modern autoflowering cannabis strains now test at 20%+ THC, with rich terpene profiles that rival their photoperiod parents.
That said, photoperiod cannabis still holds the edge in top-shelf genetics. If you’re after boutique bud or rare terpene profiles photos give you more depth due to their longer flowering timelines.
But if you just want solid smoke without stress? Autos deliver. This is especially true when you are using quality genetics from trusted breeders.
7. Cloning and Reproduction
If you are a cannabis enthusiast who loves to take cuttings and repeat your grow, here’s the kicker.
Photoperiod cannabis plants can be cloned. That means one mother plant can produce dozens of genetically identical offspring. This is great for pheno hunting or preserving a perfect plant for the next grow.
Can you get seeds from autoflowering cannabis? Technically, it is possible to obtain seeds from autoflowering cannabis through breeding. But cloning autoflowers is mainly regarded as ineffective. By the time a clone roots, it’s already flowering, which translates to minimal time in the vegetative stage to grow big.
So for breeding, cloning, and genetic control? Photoperiod is a wise option.
Autoflower or Photoperiod? Here’s How to Choose
Now that you’ve compared autoflowering vs. photoperiod, it’s time to make a choice.
If you have limited room or basic gear or want a no-fuss routine, cannabis autoflower seeds make your life easier. They’re fast. They don’t wait for you to flip a switch. And they forgive errors most beginners make.
But if you’re ready for deeper control and larger results, photoperiod cannabis seeds are a solid investment. You achieve higher yields, stronger genetics, and the ability to shape each plant through techniques such as topping and training.
Can you Grow Autoflower and Photoperiod Together?
There’s no universal answer to the debate between autoflower and photoperiod. It’s about what suits you at this moment. Even better, you don’t have to pick one forever.
You can run both in a tent under an 18/6 light schedule. Allow the autoflower cannabis seeds to grow naturally while keeping your photoperiod plants in the vegetative stage. Once the autos finish, flip your photos to 12/12 and let them flower.
Want another trick? Stagger them. Begin by planting one auto and as it approaches its budding stage, get a photoperiod and mix it up. Happy growing.
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