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The Easy Guide to Understanding the Different Cannabis Photoperiod Types

Cannabis is a photoperiodic plant meaning its growth responds to any changes in day length. To be more specific, these kinds of plants react differently to changes in the light cycle, which is something that happens many times throughout the year. For example, in the Northern Hemisphere, daytime in the summer usually lasts much longer than in the winter.

One important thing to take note of with cannabis plants is how their responses are very noticeable to photoperiod changes. On paper, growing cannabis seeds seems like an easy thing to do, but as you start to dig deeper and gain more knowledge, you’ll soon realize that not all cannabis seeds are made the same. Basically, there are three kinds of cannabis seeds:

  • regular,
  • feminized,
  • and auto-flowering.

Each seed type has different flowering periods, yields, and growing requirements. Knowing how the seeds differ from one another and the conditions they need to grow is essential for beginners.

So, let’s have a closer look at the different types of cannabis seeds.

Feminized Seeds

These seeds are genetically altered so they produce no male parts. When fully mature they produce an all-female crop 95% of the time. This is beneficial for growers seeing as how female plants are the only ones that produce flowers. Male plants do not produce any flowers, have very little THC, and are known to negatively affect the production of THC in female plants.

Female plants contain many of cannabis’ important components such as CBD, THC, and CBN compared to male plants. Before being sold in the market, female seeds sometimes undergo thorough testing and further cultivation to ensure that they are stable and genetically consistent. However, most cannabis seed companies that produce female seeds usually avoid this lengthy and costly procedure.

In many instances, feminized seeds will end up becoming hermaphrodites meaning they will produce have male parts that will produce pollen, thus leading to seeds. Additionally, feminized seeds tend to have lower yields. Using colloidal silver to produce female seeds helps reduce the likelihood of them becoming hermaphrodites.

Many experienced growers don’t use feminized seeds, and they should never be used for breeding. This is because they were made without true males meaning they will be genetically inferior.

Unlike with regular seeds, growers don’t have to germinate twice the amount of seeds with feminized seeds since they’re all already guaranteed to be females. Instead, you only need to start go with as many as you need. Then during the flowering stage, you can expect females will produce calyx-shaped pods like teardrops.

Auto-flowering Seeds

Auto-flowering seeds are produced when ruderalis genes are introduced to a regular strain. These plants are generally smaller in size when matured making them ideal for outdoor growing. Unlike feminized strains, auto-flowers do not rely on seasonal light cycles to flower. While most cannabis strains will flower at the end of summer right when the amount of light starts to drop due to the days becoming shorter, auto-flowers are different. These strains will go through the flowering stage even if they get light for 24 hours.

Auto-flowering seeds will reach maturity within 10 weeks at most from start to finish. There are also feminized auto-flowering seeds that give growers a quick harvest without any males to worry about. Auto-flowering seeds can produce 2 harvests in the span of one summer. However, autos generally have lower yields and can have diminished quality compared to regular or feminized seeds.

Regular Seeds

Regular seeds are produced by one male and one female parent. When they grow, they will turn to be either male or female plants. There is virtually no way for anyone to tell if a regular seed will grow into a male or female. They become easier to identify as soon as they enter the flowering stage. Males have oval-shaped pods while females’ pods look like teardrops with one to two pistols emerging.

With regular seeds, it is best to assume that you will get 50% male and 50% female seeds. When growing regular seeds, one should germinate a few extra ones to help them make up for all the males that will get discarded once the plant enters the early flowering stages.

Certain variables come into play in determining if a grower should go with regular seeds over feminized ones. These variables include the growing conditions, level of expertise, and the amount of time and grow space available are things one should consider.


Before choosing what kind of seeds to grow, it is important for the grower to know what he/she intends to do. For instance, if you are looking to breed cannabis and produce new seeds, then you’ll need to have a male and female plant which requires the use of regular seeds. But if your intention is to simply harvest cannabis buds for personal use, or are limited by laws restricting plant count, then feminized seeds may be the better option. Growers who want to have multiple harvests in one harvest season should go with auto-flowering seeds. Remember that in the end it will come down to your personal preference.