Cultivo macetas

How to grow autoflowering cannabis seeds

  • When it comes to autoflowering strains, aspects like when and where to start the seeds, the duration of the vegetative period, why the strains flower and when to harvest them need to be taken into consideration. 
  • Autoflowering cannabis strains have the advantage of being faster that feminised strains and the disadvantage that they don’t depend on light intervals, meaning that outdoor conditions need to be as favourable as possible for the buds to develop properly.
  • We give you the lowdown on how to grow autoflowering plants for a truly successful crop.
Cultivo macetas

Autoflowering, auto, automatic, you name it. And yet all these designations refer to the same cannabis seed type, i.e. strains that do not depend on light intervals and thus grow and flower when they reach maturity, regardless of the photoperiod.

We get lots of comments and questions about growing autoflowering seeds via our social media channels, mainly from growers who wonder things like "when should I harvest," "why is the plant flowering if I started the seed just one month ago" or "shouldn't it be bigger before it starts producing flowers? In this post, we've put together some of your main concerns regarding autos and we'll look at them one by one. And if you've got any more questions, you can leave a comment below.

What are autoflowering cannabis seeds?

Autoflowering cannabis seeds are strains whose life cycle duration is pre-defined. Unlike feminised strains, they start to flower when they reach maturity and not upon a photoperiod change, meaning that they invariably flower 25-30 days after germinating the seeds. This makes them very fast, with complete life cycles of about 55-65 days. The possibility to harvest the buds in such a short period of time is definitely an advantage for those who seek speed, but there are also a couple of downsides.

If you want your crop to be generous, there are two aspects you should consider. One: Providing the plant with as much light as possible during the first 30 days of life -vegetative period - so as to encourage growth. Many of you tell us your plants start to flower when they're still too small. Why is that so? Most of the times it is simply because the plant has been grown outdoors and the weather was not good enough. If you start an auto, let's say on the balcony at the beginning of summer, but sunlight is absent and temperatures are cool, the plant won't be able to grow because cannabis thrives in temperate, sunny conditions. 


Two: Avoiding pests by all means. If the plant gets infested, there's virtually no time to turn things around before flowering, so you really need to pay close attention to the health of your autos. Let's take an example. If leaf miners infect your plant 20 days after germination, you'll only have a few days left to apply a fumigation treatment, as once the plant starts to flower, whatever you spray will contaminate the buds - and you don't want to consume those flowers.

What is the origin of autoflowering cannabis seeds?

Autoflowering seeds are cannabis species that contain ruderalis genes as part of their genetic makeup. Ruderalis strains are native to areas like southern Siberia, northern Kazakhstan and Russia, which are characterised by extreme weather conditions, meaning that ruderalis strains are used to fighting for survival in climates which are unfavourable for plant development. Hence their speed: if they weren't fast, they wouldn't survive. 

Strong and hardy, they are also very easy to grow, requiring very little maintenance and growing fast and vigorously. Again, their aim is to flower as soon as possible because they know the risk of dying is high. But since their genetic makeup was forged in extremely hostile environments, they know how to deal with adversity.

When to start autoflowering cannabis seeds

This question, of course, comes from outdoor growers, but to give you an idea of how important light is for autoflowering strains, you should know that, as a rule, indoor-grown autos receive 20 hours of light per day under the lamps - the amount of light exposure necessary to artificially create the optimum conditions for the development of autoflowering plants can be used as a reference for outdoor-grown plants. In any case, it all comes down to one very simple principle: the more light, the better. So going back to the question of when to start the seeds, a general rule of thumb is trying to make the vegetative period coincide with the sunniest time of year, which will depend on aspects like the weather and latitude of the region you live in.

When to harvest autoflowering cannabis seeds 

Seed banks usually include the duration of the plant's life cycle on the labelling, so when you start your seeds, you will already have an approximate idea of when to cut the buds off. However, if you want to nail the timing, there's nothing like observing the colour of the trichomes - the buds will be ready to harvest when they are well formed and the trichomes start to take on brownish hues. 


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