Fast-Flowering vs. Photoperiod Strains: What's the Difference?

The difference comes down to speed and control: photoperiod strains flower only when you switch the lights to 12/12 and take longer to finish, while fast-flowering strains also wait for that light switch but wrap up flowering in around six or seven weeks. Growing cannabis is a long but rewarding ride for dedicated growers, and some prefer strains with shorter life cycles so they can harvest their buds sooner; if that's you, fast-flowering strains are what you're after.

These strains are a unique option that doesn't skimp on quality. The buds are just as potent as regular photoperiod versions; the bonus is you get to enjoy them sooner.

Fast-flowering cannabis strains give growers the perfect middle ground between photoperiod strains and autoflowers. Photoperiod strains are robust, strong and potent, but they take longer to mature and depend on light cycles to move on to the next stage of growth.

Autoflowers, on the other hand, have short life cycles and flower automatically, with no option to stretch out the vegetative stage. They mature no matter how much light they get.

Fast-flowering strains sit between those two extremes. They depend on light like photoperiods but have short life cycles closer to autoflowers.

Fast-flowering strains let growers stretch the vegetative stage as long as they want by controlling the light cycle. As long as the plants get more than 12 hours of light a day, they won't flip to flowering.

Once you set the timer to 12 hours of darkness and 12 hours of light, they start flowering and finish fast. That's where a dash of autoflowering genetics comes into play.

More and more growers are going for fast-growing cannabis seeds for the convenience. These strains finish flowering in a short window of around six or seven weeks.

A great example of a powerful fast-flowering version is Green Tiger, from BSF Seeds.

Green Tiger is a strong, potent strain from an impressive lineage. With ultra-fast growth, tons of vigor and huge harvests in any growing medium, it shines in the grow room and in the bong alike. It has a sweet, fruity flavor, and connoisseurs will pick up those unmistakable skunky notes. This bomb is 20% sativa and high in THC at 22%. Indoors it can yield up to 650 g/m², and outdoors each plant can give you around 600 g (about 1.3 lb). As a fast-flowering version, it delivers top-notch buds in just 6 weeks of flowering.

Regular photoperiod seeds are made the way nature intended: they're photoperiod-dependent. They need changes in the light schedule, and they'll give you both male and female plants.

These strains start flowering once they reach maturity and sense the days getting shorter. Indoors, you can easily control the light periods: 18 hours of light and 6 of darkness during the vegetative stage, and 12 hours of light/12 of darkness for the plant to start flowering and keep going.

Thanks to photoperiod plants, you can keep mother plants and take clones and cuttings while the others keep growing under an 18/6 light schedule. If photoperiod plants stay on that light schedule, they stay in the vegetative stage indefinitely and never flower, but they take a lot of upkeep.

Whether a grower picks a fast-flowering strain or a regular photoperiod one basically comes down to patience. If you want a quick harvest, fast-flowering strains are the way to go. If you want to keep mother plants, or let the plant grow on its natural schedule, photoperiod seeds are the right call.

What's the difference between fast-flowering strains and autoflowers?

Fast-flowering strains and autoflowers are two types of cannabis that differ in how they grow and flower.

Fast strains have been bred to grow faster than regular cannabis strains, cutting down the flowering time. They're usually hybrids carrying genes from both indica and sativa strains. Fast strains can sometimes deliver a bigger, quicker harvest than regular strains, but they may need more care and attention to reach their full potential.

Autoflowering strains, on the other hand, were created to flower automatically, without depending on a change in the light cycle. That means they can be grown indoors or outdoors and deliver fast, predictable harvests. Autoflowers are often easier to grow than regular or fast strains, since they don't need the same level of care and attention.

What are photoperiod strains?

Photoperiod (or photo-dependent) strains are cannabis plants that rely on the light cycle to decide when to flower. In other words, they need a certain number of hours of light and darkness to switch from the vegetative stage to flowering. Photoperiod seeds are popular with growers who want more control over how their plants grow and bloom.

Autoflowering plants, by contrast, flower automatically and don't rely on the light cycle to decide when to bloom. They're popular with growers looking for a quick, easy harvest, since you don't have to adjust the lighting to get them to flower.

Photoperiod plants can be grown indoors or outdoors, and indoors you can set the light cycle manually to control when they flower. For example, indoor photoperiod plants are often grown on 18 hours of light and 6 of darkness during veg, then switched to 12 hours of light and 12 of darkness to trigger flowering.

How do you grow fast-flowering strains?

To grow fast cannabis strains, it all starts with the right genetics. Look for strains known for shorter flowering times. These "fast" strains are specifically bred and crossed to speed up the growth cycle and cut the time it takes to reach maturity. Popular fast-growing strains include Northern Lights, Skunk #1 and Critical. Choosing strains with shorter flowering times can seriously speed up your grow and your harvest.

It's also essential to give your plants optimal growing conditions so they can grow as fast as possible. Make sure they get enough light, natural or artificial, at every stage. Consider quality grow lights and set the photoperiod to mimic ideal flowering conditions. And keep temperature and humidity in the right range to encourage healthy, fast growth.

Feeding matters too: use balanced, quality nutrients. Follow a feeding schedule suited to each growth stage, paying special attention to macronutrients (nitrogen, phosphorus and potassium) and the micronutrients plants need to grow healthy and fast.

What are the best fast-flowering strains?

These strains usually flower faster than others:

Northern Lights:

A classic known for fast growth and flowering. It produces dense, resinous buds and is loved for its relaxing effect.

Critical:

Another strain known for its short flowering time and high yields. It's usually easy to grow and gives you big, heavy buds.

Skunk #1:

This iconic strain has a reputation for fast growth and toughness. It's a vigorous plant that produces fragrant, potent buds.

Super Lemon Haze:

It's not strictly a "fast" strain, but it has a fairly short flowering time for a sativa. It's known for its citrusy flavor and energizing high.

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