How to grow autoflowering cannabis strains outdoors

by | Apr 28, 2021

Would you like to harvest more than once a year? Though autoflowering cannabis plants are generally smaller than their photoperiod counterparts, they also have advantages.

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 dependent on a 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 is adapted to a short summer. The original Ruderalis is a small plant producing very little THC and has 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, created in 2000, weren’t particularly tasty, heavy-yielding. However, after many generations improving them through the use of the most technologically advanced breeding techniques, the autoflowering strains now on 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: Despite there being increasingly more exceptions, autoflowering strains are generally smaller than feminized plants, meaning they are perfect for those gardens 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 adjust light 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.
  • Resistance to pests: A fast life cycle means a higher resistance to pests, disease and fungus since they don’t have enough time to cause severe 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.

When to germinate autoflowering genetics?

It all depends on your region and 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 a year are higher.

  • In warm climates: 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 cold climates: 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 can be germinated using the same germination methods as with the other photoperiod seeds. See our germination guide for tips.

Which type of pot to choose?

We advise you to start your cultivation with a flowerpot of at least 2 gallons. However, using a 5 gallon 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.

Bubba Cheese Auto

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 3 gallons 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 sparingly but frequently to foster oxygenation. Avoid over-watering to prevent drowning their roots. We cannot give you the exact amount because it depends on many variables like the climate and soil. As a general rule, 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 pests 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 organic methods. When it comes to fungi, avoiding over-watering your plants and making sure the growing area is clean and tidy.

Happy growing!
~ The Humboldt Seeds Team

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