How to grow autoflowering cannabis strains outdoors

Summer is a good time to grow autoflowering plants. The longer days, more hours of daylight and higher temperatures make the perfect scenario for growing autoflowering cannabis plants outdoors in optimal conditions. Despite there being certain misgivings about them, autoflowering genetics offer a wide variety of advantages and, after years improving them, their quality in terms of yield, flavor and potency has nothing to envy to their photoperiod counterparts. If you’re still unsure, we advise you to give these cannabis sprinters a chance. To make sure everything runs smoothly, here is how to grow autoflowering cannabis strains outdoors.

What are automatic marijuana strains?

Unlike feminized genetics, autoflowering cannabis strains aren’t subject to a photoperiod and their life cycle is far shorter. While a photoperiod plant has a lifespan of some 4 months from germination, automatic strains only need 3 months and sometimes even less. Not depending on the photoperiod, they’re easier to grow because changing the light cycle when indoors is not necessary. Outdoors, if living in warm regions, they may even be harvested more than once within a year. Besides, the more daylight and heat they receive, the more they’ll grow and the more bountiful their crops will be.

The fast growth and amazing resistance of automatic cannabis seeds are down to their Ruderalis predecessor, a strain born in Siberia that at some point had to adapt to the short summer in this kind of regions. The original Ruderalis is a small plant producing very little THC and with a strong taste of freshly-cut grass. This is because she has to devote all her energy to thriving in a hostile environment: extreme cold, very few hours of daylight and low light intensity.

The first autoflowering strains, born by the end of 2000, weren’t particularly tasty, heavy-yielding or potent because crossing them with a Ruderalis meant that the features of the other parentage were somehow cut down. However, after many generations improving them through the use of the most technologically advanced breeding techniques, the autoflowering strains now in the market offer the same quality as their photoperiod sisters do.

Benefits of autoflowering cannabis strains

  • Rapid growth: The main strength of automatic genetics is their fast growth. While photoperiod strains need at least 4 months to be ready for harvest, the life cycle of some auto genetics barely exceeds 2 months, although the average is 3 months. This means they may even yield several crops per year, two or maybe three in those southern regions where the warm season can last until late October.
  • Discretion: One man’s priceless is another’s worthless. Despite there being increasingly more exceptions, autoflowering strains are generally smaller than feminized plants, meaning they are perfect for those cultivations where discretion comes first. So you can get an idea of what we’re talking about, Blue Dream can reach up to 10 ft. outdoors whereas Blue Dream Auto rarely gets above 5 ft.
  • Easy to grow: Autoflowering genetics are particularly suitable for beginners. If indoors, there’s no need to change the life cycle for them to start the flowering phase. They’ll do so by themselves, in just a few weeks, and the size and yield they finally get to offer will solely depend on the amount of fertilizers and hours of light they’ve received.
  • Higher resistance to plagues: Their life cycle being so fast entails a higher resistance to plagues and fungi since they don’t have enough time to cause great damage.

How to grow autoflowering marijuana seeds?

Maximizing resources right from the start

The life cycle of autoflowering genetics is so short that maximizing resources from the very beginning is vital. While feminized plants have time to recover from plagues or nutritional issues, any of these mishaps could cause great trouble when growing autoflowering strains. In order to avoid this kind of problems, planning everything to the smallest detail from the start will help your plants make the most of the available resources.

When to germinate autoflowering genetics?

It all depends on the region you’ve decided to grow in and on its climate. Autoflowering genetics love warm climates where winters are mild. There, they can be grown even when summer has ended, meaning the chances of harvesting more than twice in a year are higher.

  • The Mediterranean area of Europe: You can sow the first crop in mid-April/early May, once you know for sure there’s no danger of frost and the days are longer. This way, you’ll be harvesting by late July and still have time to plant another crop in early August and harvest it in October.
  • In Atlantic, central and northern Europe: Here, it rains a lot, there is less sunlight and summers are shorter, which means you’ll only be able to harvest once. Ideally, you should sow in early June to be able to harvest in late August.

How to germinate?

Autoflowering cannabis seeds are to be germinated using the same germination methods as with the other photoperiod seeds. You can choose the one you like most but, if you still aren’t sure, we recommend following the tips provided by our expert collaborator Light Addict.

Which type of pot to choose?

We advise you to start your cultivation with a flowerpot of at least 7 L. However, using a 15 L pot will allow your plants to grow bigger. Choosing the right size is very important because it will be the definitive pot. Unlike photoperiod plants, transplanting autoflowering plants in the middle of their life cycle is not advisable because they get stressed out.

Preparing the soil

Automatic genetics need a well-aerated substrate that allows them to take advantage of all the available resources in order to develop their roots and accelerate their metabolic processes. We recommend using 10 L of substrate comprising 1/3 of coconut fiber and 2/3 already-prepared peat moss or substrate, which you can find in any grow shop. If you’ve decided to go organic, here’s how to prepare a top-quality super soil that will provide your plants with all the nutrients they need to show their best potential.


It is advisable to water them sparingly but frequently to foster oxygenation. Avoid overwatering them to prevent their roots drowning. We do know it is not easy to find the right amount because it depends on many variables like the climate or the environment. As a general rule, you have to make sure the soil is humid and the pot is not too heavy.

Fungi and pests

As mentioned before, autoflowering genetics are far more resistant to plagues than photoperiod plants because insects don’t actually have enough time to become a real problem thanks to the short life cycle of these strains. This doesn’t mean they’re immune to pests. So keeping an eye on them is still highly necessary. It’s always good to take preventive measures using a wide variety of organic methods. When it comes to fungi, avoiding overwatering your plants and making sure the growing area is clean and tidy should do.