Autoflower

Autoflower

Autoflower is the term for cannabis plants that begin to flower based on their age rather than the amount of daylight they receive. The name is short for "autoflowering", meaning the plant switches to flowering automatically.

More about Autoflower

Most cannabis plants are so-called photoperiod plants. They stay in the growth phase as long as the days are long, and only start forming flowers when the nights get longer in late summer and autumn. Autoflowers do not react to this signal. They move into flowering after a set number of weeks, regardless of how much light they get.

The trait comes from Cannabis ruderalis, a small and hardy type of cannabis that grows wild in Central Asia and Russia. In regions with short summers and long days, flowering by age rather than light is an advantage, since the plant would otherwise not finish before the cold arrives. Modern autoflower varieties are crosses between ruderalis and other cannabis types, which is why they are usually smaller and more compact than photoperiod plants.

Because autoflowers follow a fixed internal clock, the term is often mentioned alongside words such as feminized seeds and Low-Stress Training (LST), which describe other aspects of how plants are bred and shaped. Autoflowers are also rarely used as mother plants, since cuttings from them keep the same age as the original plant.

Where autoflowers come from

Cannabis ruderalis was first described by the Russian botanist Dmitrij Janischewsky in 1924. For decades it received little attention, because the wild plant is small and produces few flowers. That changed in the early 2000s, when the breeder known as the Joint Doctor released Lowryder, widely regarded as the first commercially successful autoflower. Since then, autoflowering genetics have become a large category of their own, both in cannabis and in hemp breeding.