Key facts you should know about photoperiod cannabis (2024)

What are photoperiod cannabis plants?

Photoperiod cannabis plants are popular with both indoor and outdoor growers. Until autoflowering cannabis seeds hit the mainstream, photoperiod plants were the only ones available to growers. Even today, many growers prefer to grow photoperiod plants, regarding them as the ‘original’, natural and preferred genetics.

Photoperiod plants have 2 distinct phases to their lives, growth and bloom. This allows the grower a certain degree of control over the growth and development of the photoperiod plant. For some growers, this enhances their enjoyment of the cultivation process.

Unlike autoflower strains, photoperiod plants can be used as mother plants - if necessary for many years. Numerous cuttings can be taken from a photoperiod plant. Re-vegging of harvested photoperiod plants is also possible. Autoflower seeds and feminised photoperiod seeds each have their own advantages and disadvantages. But for some old school growers, there is nothing quite as good or as flexible as photoperiod cannabis strains.

Photoperiod vs autoflowering cannabis strains

Autoflowering seeds have earned a reputation for convenience, speed and simplicity. It’s difficult to argue against some of the great benefits offered by autoflowering cannabis seeds. Autoflower seeds have become a valuable resource for many cannabis growers. But they may not always have the best fit for every grower.

Many home growers love to maintain a mother room of elite cuttings taken from their favourite photoperiod plants over their growing career. Lots of growers will harvest a plant and fall in love with the genetics. Photoperiod plants can be easily re-vegged. Just leave some green foliage on them after harvest and put the plant back under 18-24 hours of daily light and she will restart vegetative growth.

SCROG growers often prefer growing from photoperiod feminised seeds in order to have the control to fill the SCROG screen. You don't want the hassle of removing a male plant from your SCROG net!

Choosing when to start bloom and see the plant stretch is easy with photoperiod cannabis strains. You just flip the lights to bloom conditions. Conversely, autoflower plants have a rigid life cycle that can't be manipulated. For some growers and some grow techniques, autoflowering cannabis seeds are simply less preferred than photoperiod feminised seeds.

Photoperiod cannabis strains and how genetics shape them

Photoperiod cannabis strains are available with a huge range of different genetic backgrounds. Some of the genetics are selectively bred for indoor growth, others for outdoors. Some photoperiod cannabis strains are sativa-dominant, others are indica-dominant.

You can choose THC rich strains, CBD rich strains or even THCV rich seeds such as Dutch Passion's THC-Victory strain, the world’s first THCV rich cannabis strain. CBG rich feminised seeds are also available, look out for Dutch Passion’s CBG-Force seeds!

You can even grow photoperiod cannabis strains with leaves that look nothing like cannabis! Frisian Duck is a favourite with outdoor growers. The webbed leaf shape looks nothing like the iconic cannabis leaf, you could walk straight past it and not realise its cannabis.

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Frisian Duck plant of the year

Sativa or sativa-dominant photoperiod feminised strains

Sativa, or sativa-dominant cannabis strains are those that allow the sativa genetics to shine through. For the grower this can mean a somewhat longer flowering time than an indica dominant strain. Plants grown from sativa cannabis seeds (or sativa dominant cannabis seeds) often take around 10 weeks (or longer) to finish bloom.

Sativa strains may also have leaves with thinner ‘fingers’ than those on indica leaves. This can make them more suited to SCROG grows where the leaves block less light than eg a broad leaved indica variety. Sativa varieties often stretch a little more than other varieties, resulting in taller plants (or plants more suited to filling a SCROG screen, perhaps).

Outdoor growers often need to consider the harvest date when selecting their outdoor cannabis seeds. Sativa varieties can have very late harvest dates. Make sure that your local climate supports these late harvests. There is no point trying to grow a Haze variety with a November harvest date in northern Europe, for example.

Sativa buds are often a little less dense/compact than indica buds. This makes them slightly less prone to bud rot in humid conditions. The sativa high is often described as energetic, creative and cerebral. For some nothing else quite compares with the joy of a soaring, psychedelic sativa.

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Top 5 sativa cannabis seeds

Indica or indica-dominant photoperiods cannabis strains

Indica, or indica dominant cannabis has several contrasting differences to sativa strains. Indica strains tend to have a short bloom time of around 8 weeks. Often this is a couple of weeks faster than sativa strains. Indica leaves are often broad, with wide leaflets. Some SCROG growers dislike growing indica strains since the leaves can block light from penetrating lower bud points.

Plants from from indica seeds are often shorter, squatter and bushier than those grown from sativa seeds. This can make them popular with indoor growers, especially those with height restricted grow rooms. Buds grown from indica seeds often have a fast hitting effect, with a strong body stone and highly pleasurable lazy couch-lock enjoyment. For many growers, dense indica buds produce an unbeatably pleasurable body stone, a great high and Grade-A relaxation qualities.

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The best 5 indica cannabis seeds

Hybrid photoperiod cannabis strains

Hybrid strains enjoy a satisfying blend of both sativa and indica genetics. For many growers, hybrid cannabis seeds offer the best of both genetic worlds with the most enjoyable experience. You can enjoy strong cerebral and physical effects. Bloom time is usually somewhere between that of a pure indica and a pure sativa. So expect bloom times of around 9-10 weeks.

But note that some hybrid phenotypes will lean slightly towards indica dominance. Others may lean a little more towards sativa dominance. Hybrid cannabis strains tend to be taller and stretchier than indica strains. But they are often a little shorter with reduced internodal distances compared to pure sativa or Haze strains.

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The best hybrid cannabis seeds

Photoperiod cannabis plants life cycle

Photoperiod cannabis can be controlled in both main phases of its life cycle, growth and bloom. During the early part of life, vegetative growth is maintained with the use of long daylight hours e.g.18 hours (or more) of daily light. Only when the grower is ready for bloom to begin are daylight hours reduced to around 12 per day. This causes changes to plant hormone levels which initiates bloom.

Ability to manipulate growth via control of vegetative conditions

If you are growing with restricted head room then you can grow your photoperiod feminised seeds with a short period of veg growth. This allows you to control the overall size and stretch of your plant. You may also wish to select indica or indica dominant seeds to conform with your low-height grow style.

Conversely, those with larger grow rooms can offer their plants much longer veg periods. 4-6 weeks is normal. But those that wish to completely fill a tent (or a SCROG screen) with a single plant may prefer to use longer veg periods. The choice is down to the grower. But one key advantage of growing photoperiod feminised seeds is the ability to retain some degree of control over your plant size/structure as well as controlling when it starts to bloom. This option is not available to growers of autoflowering cannabis seeds.

Photoperiod plants can be re-vegged easily if you find a ‘keeper'

It can be frustrating to grow a fantastic quality autoflower and be unable to re-grow (or ‘re-veg’) the plant. However, a plant grown from photoperiod feminised seeds can be re-vegged. That means, once you have harvested your photoperiod plant, you can grow it and harvest it a second time (and even a third!).

After harvesting a photoperiod plant simply leave some green foliage (leaves, small buds etc) on the plant. This will allow it to photosynthesise when placed back under vegetative growth conditions (18 hours of daily light). Simply leave the plant for a couple of weeks, water occasionally, and you will notice the plant springing back to life. When you are ready, flip the lights to 12/12 and bloom your favourite plant once more.

Photoperiod plants are easy to take cuttings from and use as mother plants

Many growers, especially commercial growers, like to take cuttings if they find a particularly special mother plant. One advantage of taking clones is that they are genetically identical. If you have a large commercial crop it makes life easier if all your plants grow at identical rates and use the same nutrients at all stages of growth. That’s one of the advantages of growing clones. You have predictable growth and nutrient management. You also have the quality/yield guarantees that come with growing clones from a known mother plant.

One comparative disadvantage of growing from autoflowering cannabis seeds is that you can’t take dozens of cuttings and maintain a mother plant over several years. On the other hand, most home growers don’t need to do that. Many home growers just grow a few plants each year for their personal use using autoflower seeds or feminised cannabis seeds.

Photoperiod plants are easy to get into SCROG and SOG growing

Being able to manipulate the growth characteristics of your plants is one of the great benefits of using photoperiod feminised cannabis seeds. SCROG growers can keep their plants in veg as long as necessary in order to get their SCROG screen sufficiently full. Autoflower seeds may well be easy, potent and convenient to grow, but they (rather than you) decide when to start bloom.

SOG (Sea Of Green) growers like to grow large numbers of plants with large main blooms and little veg growth. Again, without the ability to control and steer veg/bloom, autoflowers are not optimised for SOG grows.

Photoperiod cannabis plants are easy to breed

Although not many people make their own seeds, photoperiod regular seeds are easy to make yourself. Just buy yourself some regular photoperiod seeds, and keep a male and female in close proximity.

Use a paint brush if you wish to apply the male pollen liberally over the female flowers, or let the grow room fan do the work! Then just wait a few weeks for the seeds to form. It’s that easy to make your own regular seeds.

Of course, making photoperiod feminised seeds is more difficult. Making feminised autoflower seeds is also demanding, most people buy them rather than try to make their own. For most home growers the fun is in the production of buds.

Indoor vs Outdoor photoperiod cannabis possibilities

Photoperiod cannabis plants can be grown indoors or outdoors. The best cannabis seed companies take many years to selectively breed their outdoor cannabis strains. Outdoor cannabis seeds are bred to grow well even in tough outdoor conditions.

They are resistant to mold and rot. Good quality outdoor cannabis seed varieties finish early, before the winter storms arrive. Often, but not always, cannabis growers often select different varieties of cannabis seeds for indoor and outdoor growing. Most outdoor growers choose feminised outdoor seeds. No-one wants to send months growing an outdoor plant in your best location only for it to turn out male.

Those that grow outdoors simply don't need to worry about electricity costs, PPFD light levels and odour control. Just find a safe and suitable grow spot and buy the best feminised outdoor cannabis seeds you can. Successful outdoor growers often produce their annual cannabis needs from a few plants, for very little cost.

Related:
Top 5 outdoor cannabis seeds

Choose your outdoor cannabis grow location wisely

Find a sunny spot with shelter from the prevailing winds if possible. Choose a spot with good quality soil, or bring your own soil to the location. You may need to protect the plants from local wildlife (rabbits, deer, goats etc).

Look out for climate changes, understand your local weather

Many outdoor growers put their photoperiod plants outdoors after the last frost. Where possible, the plants are kept in greenhouses (or indoors) until the outdoor weather is good enough. Understand when cold, winter weather arrives at your latitude and select outdoor photoperiod feminised seeds which finish in time. If winter arrives early at your latitude then you may be safer using autoflower seeds.

Beware of light exposure during nighttime

The presence of powerful outdoor lights at nighttime, such as security floodlights, can prevent a photoperiod cannabis plant transitioning into bloom phase. Photoperiod plants don't need complete darkness outdoors - they get used to the moon, for example. But intense night lights can cause problems.

Only use high quality genetics

Most people don't grow that many cannabis seeds each year. The cost difference between the cheapest cannabis seeds and the best cannabis seeds is generally just a few euros per seed. So buy the best feminised cannabis seeds you can get from a seed company that you can trust. Remember that high quality seeds are just the starting point of your grow. You also need to ensure a good quality growing environment as well as keeping your plants in the nutrient sweet spot from seed to harvest.

Best photoperiod cannabis seeds

Which are the best photoperiod feminised seeds for you? It all depends on the things that are most important to you. A really great taste? A strong high, but not too powerful? The following list of different cannabis seed categories may offer some useful inspiration.

Feminised THC rich cannabis seeds

Most people choose THC rich seeds. The most potent dozen (or so) strains in the Dutch Passion collection form the elite ‘Extremely High THC seeds’ family. If you want to get really high, without compromise, then these are the best feminised seeds for you.

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Dutch Passion’s elite ‘Extremely High THC seed’ collection

Feminised CBD cannabis seeds

Many growers also love growing some plants with a little (or a lot) of CBD in them. CBD rich cannabis seeds are popular with medical growers. But many recreational growers also enjoy a 1;1; THC:CBD strain. You can still function reasonably well after a small vape of a 1:1 strain, but you definitely feel the pleasurable effects as well as the physical benefits.

Feminised THCV cannabis seeds

THCV (Tetrahydrocannabivarin) rich strains such as THC-Victory are also available. Dutch Passion are particularly proud to be first to offer feminised THCV seeds.

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Special cannabinoid cannabis seeds

Feminised CBG cannabis seeds

CBG rich strains are also available. Dutch Passion were proud to be the first to offer CBG (Cannabigerol) rich seeds. CBG-Force feminised CBG rich seeds are particularly interesting to the medical cannabis growing community. Auto CBG Force is the world’s first autoflowering CBG seed variety.

Best cannabis seed recommendations from the experts

Each one of us has a different endo cannabinoid system. We all respond slightly differently to different ratio’s of cannabinoids found in different strains. You may be lucky enough to have already found your favourite strain that ticks every box. But if you haven’t yet found your ideal variety then the following articles listing the best cannabis seeds may be useful reading.

If you have specific needs from your next grow then try our Seed Finder tool. This asks you various questions about everything from the type of high you want to the amount of space you have to grow in.

Whether you grow indoors or outdoors, there is a photoperiod cannabis strain which will fit your growing needs as well as providing a top quality vape/smoke. If photoperiod feminised seeds don't fit with your own growing style/situation then autoflower seeds are another great possibility. However you grow your cannabis, have fun doing it!