A Basic Guide to Autoflowers
What is an Autoflower?
An autoflower is a plant that flowers regardless of the light cycles it receives - if you give it 24hr of light with no dark period it will still flower.
Autoflower plants came about from the introduction of cross breeding cannabis ruderalis to the beloved cannabis sativas and cannabis indicas that we enjoy. At first, most of the plants were small and lacked enough THC and CBD production to be considered ‘potent’ but they had the advantage of being able to autoflower. This changed with the introduction of the original LowRyder strain by The Joint Doctor. After its introduction, growers and consumers came to the realization that this new breed of autoflowering plants was capable of producing a decently potent product and decent yields (although still being relatively small plants). However, there was still room for improvement especially in order be accepted by mainstream growers of the time and subsequently a group of breeders dedicated work towards the improvement of autoflowers. Nowadays, there are plenty of autoflower genetics that can regularly produce upwards 20+% THC, and some even in the 25-27+% range, and plants that can easily get upwards of 6feet/1.8m in as little as 9-10 weeks from seed. Needless to say we have come a long way from some humble beginnings.
Pros and Cons
There are some advantages to a plant that flowers regardless of the light schedule it is given. When growing indoors, plants can be grown to harvest in a veg space, grown without the need for light timers, or grown in spaces that are not light tight (which would prevent photoperiods from flowering or cause stress to the plant to the point of unwanted hermaphroditism). Autoflowers typically finish in less time than photoperiods, with quite a few breeds finishing in 8-9.5 weeks from seed. Lastly, there can be a higher yield achieved in the same amount of time compared to photoperiods because autoflowers can be grown on longer light schedules (ie more energy can be provided to the plant). When growing outdoors, autoflowers can be harvested earlier due to there set lifespan, be planted at any point during a season (so long as they have time to finish), and provide for a couple of harvests per season. Autoflowers can also be grown in regions that are not conducive for outdoor photoperiod growth due to the shorter growing season (ie balance of light and dark periods).
One of the limitations of autoflowers is that it runs on a genetic clock. As such, there is less opportunity to resolve a problem during its growth period whereas issues arising from photoperiods can be resolved during the vegetative growth period. The genetic clock also limits the ability to veg a plant to fill a space or size before inducing flowering. Another limitation of autoflowers is mother plants and clones cannot be created due to the genetic clock. Clones or mother plants that are created would finish on the same time schedule as the original plant - autoflowers can only be grown from seed. As such, growers would need to either acquire more seeds or create their own seed (which I see as a good thing).
Growing autoflowers is the same as growing photoperiod plants but there are some helpful tips on how to get the most out of your autoflower plants. Autoflowers should be grown as smoothly as possible to avoid any growth issues. It is easier to adversely affect an autoflower due to its short lifespan, so it may be best to start new if there is an issue in the first couple of weeks. Autoflowers can take a punishment but the end yield and product will suffer.
Autoflower plants also should be started in their final container size in order to avoid transplanting. Transplanting can happen but, if it is not done early on, the plant can stall out due to limited root space which can result in a reduced yield or quality. Pruning and training can be done when needed but only sparingly, as any drastic changes can stunt the plants.
The standard light cycles for autoflowers range from 18/6, 20/4, to 24 hours. Plants will still flower with 10 or 12 hours of light however the yield will be reduced.
Seed Making, Breeding, and Different Autos
Autoflowers’ genetic trait is a recessive gene and this impacts seed creation. When breeding an auto with another auto, the recessive gene is carried over. However, when an auto is crossed with a photoperiod, 100% of the offspring from those pairings will carry both the dominant and recessive gene. The offsprings are crossed again and, in this second crossing, roughly 25% of those plants will be true autoflower plants.
There are two way to breed seeds. The standard is with Regular Auto genetics by using the pollen from a male plant to fertilize a female plant to produce seeds. Only a few breeders actually sell regular auto seeds, due to the lesser demand for regular autoflower seeds and because feminized seeds are more profitable.
The second and more common method is to make feminized seeds through the use of Colloidal Silver, Silver ThioSulfate “STS”, or other feminizing agent to force a female plant to produce pollen. This is different than natural hermaphroditism (do some research on the subject if you want to know more).
With the modern advent of autos, there are a few crosses or types that you should be aware of that are different than straight autos. “SuperAutos” are autoflowering genetics that have been bred to flower over a longer period of time thus allowing them to grow massive plants. These plants still retain the autoflowering gene which allows for longer light cycles.
Another breed, which is not actually an Autoflowers but use their genetics, are “Fast” versions that utilize the quick flowering rate to have photoperiods finish in a shorter time span than they otherwise (for example, 8 weeks instead of 10 weeks).
Choosing Reputable Breeders and Seedbanks
Reputable breeders and seedbanks are important and not all breeders are equal. Quite a few ‘breeders’ enter the autoflower market to try and grab market shares with bulk market seeds and seeds that they have had little part in breeding, typically with genetics that are random at best. Customers expecting autoflower plants may run their plants for 8-10+ weeks before realizing that their plant is not an auto and thus having to induce flowering like a photoperiod plant.
My opinion, you should support the companies and breeders who actually put the work and dedication into breeding their own auto genetic lines and not just an auto version of their Photoperiod counterpart. I would recommend Mephisto Genetics, Sweet Seeds, and some Dutch Passion Auto’s. I haven’t tried every breeder out there but I am confident in saying that they are excellent places to start.