Cultivation Autoflowering seeds are a relatively new innovation in the world of cannabis cultivation. Descended from C. ruderalis genetics native to Russia and Central Asia, autoflowering plants do not rely on changes in light cycle to commence flowering; instead, they rely on a different set of triggers, and flower according to age and size.
What is C. ruderalis?
Cannabis ruderalis is a putative third species (or subspecies) of cannabis, and is found in northerly latitudes of the northern hemisphere, particularly in Russia. C. ruderalis is notable for its small stature, low cannabinoid levels, hardiness and cold-resistance—and of course, the tendency to flower regardless of light cycles once a certain age and size has been achieved.
Due to the extreme climate and short growing season of C. ruderalis’ natural habitat, it has evolved to grow, flower and seed in a short period of time, and does not wait until the light levels drop at the end of summer to begin flowering, as at this time frosts will already have begun to set in and temperatures will become unfavourable. Instead, once the plant has produced four or five branches and reached a height of around 50cm, it will begin to flower.
What are commercial autos and super-autos?
Over the last decade or two, breeders have experimented with crossing C. ruderalis genetics with desirable, high-cannabinoid strains to produce commercially-useful autoflowering hybrids. It is possible that certain other autoflowering landraces may also have played a part in developing the first “autos”, such as a plant known as the “Mexican Rudy” in growing circles, which as the name suggests was a ruderalis-type plant found in Mexico. The Mexican Rudy was apparently used to produce LowRyder, one of the first commercial autoflowering strains on the market.
The first wave of commercial autos, including LowRyder, are typically very small in stature (usually reaching a maximum of 40cm in height), are low in cannabinoid content, and are somewhat lacking in flavour and potency. However, successive generations of crosses and backcrosses have led to the development of a range of higher-potency strains that are generally known as super-autos. Super-autos are also typically much taller and bushier than standard autos and their ruderalis ancestor, and may reach 90-100cm in height. A good selection of auto and super-auto strains can be found here.
Autoflowering plants do not need darkness
As autoflowering plants are not dependent on changes in the light cycle to commence flowering, they can successfully be grown using a lighting cycle of anything from 16/8 to 24/0. Many growers cultivate their autos under a 24/0 regime; however, some growers believe that anything over 18/6 is overkill and that electricity costs can be reduced with no reduction in final yield if following this regime.
There is also the possibility that certain hormonal and metabolic processes do occur in darkness, and that allowing your plants to have a “rest” at night-time leads to overall increased health and vigour. However, this is purely anecdotal and there is no empirical evidence to back this up, in the case of autoflowering cannabis at least.
Autos can be grown outdoors year-round
If you are lucky enough to live in a mild to warm climate suitable for outdoor growing, the possibilities for growing autoflowering strains are endless. Taking as little as 8-10 weeks from seed to harvest, it is possible to achieve five harvests or more per year if conditions are favourable year-round—and autoflowers are so hardy that they will grow well as long as conditions remain above freezing. Autos are generally frost-resistant, but permanently-frozen conditions are too much for even the hardiest plant to tolerate.
However, it is important to remember that autos are not fully stabilised in every case (buying seeds only from reputable outlets reduces the risk here) and may take considerably longer than stated. Despite this, even the autos that take the longest to grow outdoors (eighteen weeks from seed to harvest seems to be the upper limit) they are still favourable when compared to photoperiod-dependent plants outdoors, which may require twenty weeks or more, depending on strain.
Cloning autoflowering seeds is difficult
This has led to the general belief that autoflowering cannabis cannot be cloned, as cuttings taken from a mother plant are forced to follow her “genetic timeline” and flower according to age at the same time that she begins to flower. This logic dictates that the cuttings will not reach a useful size, and yield will be negligible. However, there is a handful of growers that believes otherwise, and that have successfully managed to clone their autos and allow them to continue to grow in vegetative mode until they are almost as large as their mother. Once they reach their maximum size, they begin to flower.
The key requirement if attempting to clone autoflowering plants is to take cuttings from the lower branches only. These lower branches seem to be more hormonally stable than newer growth at the top of the plant. The main terminal stem, known as the apical meristem, is the first part of the plant to receive the signal that it is time to flower, and this information takes time to permeate downwards and signal the lower branches to flower. Thus, there is a brief window of time between the first appearance of sexual characteristics (assuming that regular, non-feminized auto seeds are used) and the permeation of flowering hormones throughout the tissues of the plant. This window may be just a few hours, and it is therefore crucial to watch your plants for pre-flowers and take cuttings as soon as they appear.
Once cuttings are taken, they should be kept under low-intensity light in moist conditions until they have rooted. Once rooted, they will undergo vegetative growth until they have reached approximately 80% of the mother’s size, and will produce comparable final harvests.