What is Autoflowering Cannabis? How does it differ from Photoperiod Cannabis? Should I grow them differently than Photoperiod Cannabis for optimal results?
My goal with this piece is to better educate the reader on Autoflowering Cannabis strains. I hope that after reading one knows the differences between Autoflowering and Photoperiod Cannabis, and how to grow Autoflowers for optimal results.
Until recently, almost all cannabis strains that were available commercially were Photoperiod, which means their life cycles change and depend upon the periods of light they receive. Longer light hours keep a photoperiod cannabis strain in vegetative mode, while shortening them will induce flowering. For example many indoor growers will run 18/6 on/off for Veg, and 12/12 or 11/13 on/off for Flower.
Autoflowers are different. They do not depend upon a shortening of light hours to begin flowering, they flower “automatically” and most finish in around 2-3 months. Why do they do this? It has to do with where they are from, far far North.
Autoflowering is a recessive gene trait that is in response to very long days and short seasons in the far north. Autoflower cannabis, or Cannabis Ruderalis, can be found natively in Canada and Russia, as well as other northern regions. In these areas there are very short growing seasons, and long days, so the recessive trait survived there as an advantage.
Do they grow differently?
Yes, they do, and an autoflower grower should be mindful of how to treat them differently. The biggest thing to take into consideration with Cannabis Ruderalis is the roots. Autoflowers are very smart, they know they only have a couple months to live, so have adapted to listen to their root system for guidance. Autoflowers react much more than photoperiods to root hormone stressors. If ruderalis roots run up against the side of a container pot early on in growth it can tell the plant “hey, this is all the space we have, stop growing!”. This is why it is often recommended to start autoflowers in a larger pot, and not transplant them. This is to reduce the possibility of root stress and harm, which generally will stunt the growth of an autoflower. Ever seen this before? This is classic stunting caused by root stress. How big would you grow if your tender only put you in that sized pot?
So, the best way to keep your autos healthy, happy, and growing to their maximum potential, is to focus on happy roots. This can be accomplished simply by starting in a larger pot so the roots have room to grow quickly, and by providing aerated loose soil, like one that has been amended with lots of perlite. One also does not want to over-water. It is best to do a watering, then a full dry before watering again. This will promote the roots to search out new soil and grow in size. When starting in a large pot it can be easier to over-water though early on, just try to only water the area where the roots are growing - they do grow quickly with autos. Autoflower roots are aggressive and fast, and sensitive, take this into greater consideration and you will have better results.
So to wrap up, don't stress the roots. Give them lots of aerated space to grow early on, and don’t over-water! Bigger root systems mean bigger autos.
additional tip: If one is using nutrients, a flowering blend can be used beginning around week 3.