Photoperiod Seeds

What Are Photoperiod Seeds?

The defining feature of a photoperiod strain is that the change in day length triggers flowering.

Indoors, this gives you control over when flowering begins. Plants are commonly kept under longer hours of light while they grow, then moved to a 12/12 light cycle to start flowering. Outdoors, the change happens naturally as the days get shorter towards the end of summer.

It is also worth knowing that photoperiod only describes how the plant flowers. It does not tell you whether a strain is indica, sativa or hybrid.

You can find photoperiod versions of indica seeds, sativa seeds and hybrid seeds. Photoperiod describes flowering type, while feminized and regular describe the type of seed. Feminized seeds are bred to produce female plants; regular seeds can produce male or female plants. The selection on this page brings together feminized photoperiod strains.

Why Choose Photoperiod Seeds?

The main reason to choose photoperiod cannabis seeds is control. You decide when flowering starts indoors, which gives you more say over plant size, how long plants have to grow and how you want to manage your space.

More Control Over Plant Size

Because you choose when to start flowering, you can give a photoperiod plant more or less time to grow first.

This can be useful if you're working with a certain amount of indoor space or want more control over plant size. Autoflowers work differently because they start flowering based on age. A photoperiod plant can still stretch after the light cycle changes, so allow room for further growth.

More Time Before Flowering

A longer vegetative stage gives plants more time to develop before they start producing flowers.

This can also give you more flexibility if you want to use training methods such as topping or low-stress training. You can allow the plant time to recover before switching it into flower.

More Yield Potential

Photoperiod plants can be a good choice if yield is one of your main priorities because you can give them more time to grow before flowering.

A longer vegetative stage can support a larger plant, but it does not mean every photoperiod strain is a high yielder. Genetics and growing conditions matter too. If harvest size is your main priority, our high yield cannabis seeds are a useful place to narrow down the options.

How to Choose the Right Photoperiod Seeds

Start with your available space and growing season. Then choose the flowering time and the traits that matter most to you, whether that's THC, yield, flavor or a particular breeder.

Space and growing season

Growing indoors? Plant height is one of the first things to consider. A shorter strain is easier to manage in a small tent or grow room, while taller plants need more space. You can also look through our indoor cannabis seeds for strains suited to indoor growing.

Growing outdoors? Look at flowering time as well as expected plant size. If your weather turns cold or wet early in fall, an earlier-finishing photoperiod strain is the more practical choice.

Flowering time

Want something faster? Compare flowering times. Some photoperiod strains finish much sooner than others. For a shorter schedule, our fast flowering cannabis seeds can help you narrow the range further.

THC yield and flavor

Want higher THC? Look at our high THC cannabis seeds, then weigh strength alongside flowering time and height so the strain fits your space and schedule.

Want bigger harvests? Our high yield cannabis seeds are a good place to start. A longer vegetative period offers flexibility, but the expected yield still depends on the strain and growing conditions.

Choosing by flavor? Look at the strain description and lineage for the aromas you prefer. Once you have a shortlist, compare pack size, breeder and price to make the final choice.

Photoperiod vs Autoflowering Cannabis Seeds

If you're choosing between photoperiod and autoflowering cannabis seeds, these are the main differences:

	Photoperiod Seeds	Autoflowering Seeds
Flowering starts	When the light cycle changes	Based mainly on the plant's age
Indoor light schedule	Typically switched to 12 hours of light and 12 hours of dark to start flowering	No light-cycle change is needed to start flowering
Time before flowering	You can choose how long to keep plants growing indoors	The plant begins flowering on its own schedule
Best if you want	More control over the growing stage and plant size	Flowering without changing the indoor light cycle

If you're still deciding between the two, our autoflower vs photoperiod guide explains the differences in more detail.

Are Photoperiod Cannabis Seeds Right for You?

Photoperiod cannabis seeds are a good choice if you want more control over when your plants start flowering and how much time they have to grow first.

If you'd rather grow plants that start flowering by age and don't need a change in the indoor light cycle, autoflowering seeds may be a better fit.

Compare Photoperiod Seeds From Leading Cannabis Breeders

At 420 Seeds, you aren't limited to photoperiod cannabis seeds from just one breeder.

We stock photoperiod strains from breeders including Barney's Farm, Dutch Passion and Sensi Seeds, as well as our own 420 Seeds genetics at a lower price point.

Having different breeders to choose from makes it easier to find a strain that suits what you want. Two strains may have similar names or lineage, but they can differ in flowering time, THC, yield, plant height and price.

Why Buy Photoperiod Cannabis Seeds From 420 Seeds?

Quality matters too. We batch-test our seed stock, branded seeds come in their original breeder packaging, and eligible seeds are covered by our Germination Guarantee.

You can choose between breeder-branded packs and our own lower-priced 420 Seeds genetics, with different strains, pack sizes and price points to compare.

Photoperiod Seeds FAQs

Are photoperiod seeds always feminized?

No. Photoperiod describes how flowering begins. Feminized seeds are bred to produce female plants, while regular seeds can produce male or female plants. The photoperiod strains in this collection are feminized.

How long can photoperiod cannabis seeds be stored?

Photoperiod cannabis seeds can stay viable for years if they are stored properly. Keep them somewhere cool, dark and dry, and avoid big changes in temperature or humidity.

Do photoperiod seeds need a different germination method?

No. Photoperiod seeds germinate in the same way as other cannabis seeds. The term photoperiod only refers to how the plant starts flowering later in its life.

Can you clone a photoperiod cannabis plant?

Yes. Photoperiod plants can be cloned, which is one reason some growers keep a plant they like and take cuttings from it.