Autoflowers: Bloom Breakdown

Autoflowers: Bloom Breakdown

The cannabis plant is an ancient and complex annual plant species that has grown alongside humans for thousands of years. Due to its versatile nature, cannabis has been used to cultivate a broad range of specimens from high resinous cannabidiol plants to industrial hemp. As we’ve adapted this plant to our diverse needs, careful and selective breeding has led to a marked increase of “autoflowers” in the current seed market. But what are autoflowers, and what's the hype?

Autoflowers, or ‘Autos’ are heralded as one of the plant specimens curated for “novice” growers. This is due to the plant’s ability to ‘automatically’ enter and maintain the flowering/reproductive phase of its life cycle without a photoperiod reduction, or manipulation of the photoperiod in an indoor environment. The reproductive phase naturally occurs based on genetic code and/or “stressors” placed upon the plant, making the plant an easy to grow plant specimen.  Stressors such as severe drought or early defoliation can prematurely induce the reproductive phase of the plant, giving them a reputation as a ‘set and forget’ plant.

Autoflowers stem from the wild subtype Ruderalis, which was once considered ‘useless hemp’. Through selective crossbreeding of ruderalis with regular hybridized photoperiodic cultivars, Indicas, and Sativas, resulted in the creation of hybridized cultivars known as the Autos that we know and enjoy today. The result of this crossbreeding was an easy-growing cannabis plant, containing elevated terpenoids (terpenes or “terps”) and cannabinoids (THC, THCA, CBD, etc.) compared to the base ruderalis plant. The genetic makeup of the ruderalis plant was also used to aid in the reduction of flowering/reproductive duration of many of the regular photoperiodic plants, allowing for faster crop turnover rates.  Ironically, what was once considered “useless hemp” became an essential genotype tool in breeding so many of the flowers enjoyed by people today!

Autoflower Pros and Cons


Due to the “set and forget” nature of autoflower plants, they are the first choice of many first-time growers. Regular photoperiod plants cultivars can range from being very easy plants to cultivate, to ones that are more difficult and need more skill for reaching optimum yields/results. Autoflowers do have some growth variance from one strain to another (along with varied care requirements based on your specific plant), the labor requirement is generally much lower and much more hands-free than regular photoperiodic plants.

Autoflower plants have a life span that is typically 60-90 days from sowing to harvest, whereas regular photoperiod plants are typically no less than 90 days from sowing to harvest. This duration can vary greatly based on latitude lines and growing zones when cultivating plants outdoors. On average, autoflowers mature and are ready for harvest approximately 10 weeks after planting, which gives outdoor growers the ability to achieve multiple harvests in a single season. Their short veg period inevitably leads to smaller plants, which can be ideal for some growers who need to be discreet and/or need a rapid turnover crop cycle.

Under ideal conditions, autoflowers require 20-24-hours of light throughout both vegetative and reproductive phases of the plant’s life cycle, and do not rely on a reduction in light to induce flowering. Even though growers can cultivate autoflower specimens under different lighting cycles (12:12, 18:6, 24:0), resin production and yield can be negatively impacted by a light reduction in both the vegetative and reproduction phases. Because autoflowers have the same light requirements throughout both the vegetative and reproductive/flowering growth phases, autoflowers allow a grower to establish a perpetual harvest model in the same growing space.



One of the great benefits of photoperiod plants is that you can maintain an extended vegetation phase to grow out your plants and increase your overall yield. Unfortunately, this isn’t possible with autoflower cultivars. Autoflowers are “set and forget” plants that shouldn’t be manipulated like with regular photoperiod plants. They were bred to automatically enter the flowering phase, which makes them easier to cultivate, but means that growers have limited control over the size of their plants.

As a result of their quick vegetation phase and small size, autoflowers have a smaller average yield than regular photoperiodic specimens. Due to the genetic makeup of autoflowers, these plants should not be used to create mother plants for clones, as any cuttings have a finite time to develop healthy roots before flowering. Taking cuttings can be a “stressor” to the plant resulting in stunted growth and lower production capacity of the plant, whereas regular photoperiodic cannabis plants can easily be used as “mother” plants that can be cloned, or tissue cultured, for monocropping production systems.

Training techniques such as topping and pruning are also not recommended for autoflowers, as the plant has a small window of time where they can recover. Some growers have found success with training and topping certain cultivars, but it is not generally recommended.


Growing Recommendations:

Since the Ruderalis plant is a very hardy and resilient plant, used in the creation of autoflower varieties, some of those properties are coded into the autoflowers we grow today. In order to reach optimum success, autoflower varieties still need a well-crafted growing media and high-quality amendments for the attaining healthy plants that are low in heavy metals, and safest for human consumption. Using organic amendments and growing mixes is an easy and surefire way to increase the health of your plants and the quality of your crop. It can also increase yields, compounds, and terp production.  It’s not every crop you get paid by having a higher quality, but in the world of cannabis cultivation, elevated terpenoid, compound and resin production with no PGRs, fungicides, pesticides, molds or heavy metals, elevates the flower to be more desirable, palatable, and safer for human consumption.

Here’s a quick overview on what you need for successful Autoflowers:

1. Start Out the Right Way (With Seed Starter):


Autoflowers, like other plants in their younger stages of development, can have rather fragile root systems. Using a curated mix with the right drainage, water retention, and nutrients are recommended to build strong root architecture, so the plant is not stressed when transplanted. Our Seed Starter Mix is formulated with seedlings in mind. Seedlings have specific nutrient requirements and can easily experience root burn or issues with growth if overloaded with nutrients too early in their life cycle. Seed Starter Mix contains a balanced complex of minerals and essential nutrients, designed to work with your plants to support the growth of vigorous seedlings.

 2. Find the Right Growing Mix for You!

When you’re ready to transplant your autoflower seedlings into a high-quality growing media, we have a selection of soil mixes for every grower:

Looking to take the guesswork out of growing? Whether growing autos or photos, cannabis is a plant that has very specific nutritional needs and the biology (microbes) included in the compost of the product, delivers the nutrients to the plant when the plant requires. Autoflowers have a rapid life cycle, so you can’t pay catch-up with nutrient deficiencies. Purple Cow IndiCanja is a water-only living supersoil, that contains the complete spectrum of macronutrients, micronutrients, and trace minerals essential for healthy plant growth. No added nutrients required! IndiCanja is OMRI Listed to support the goal of cultivating ‘cleanly’ grown plants. Crafter’s Mix is the perfect soil for growers who prefer a material high in organic matter, rich in humates, and like to “craft” the nutrient program! Made from our organic plant-based compost, peat moss, and perlite, Crafter's Mix contains a light starter fertility to help establish your plants, but is customizable to fit with any grower's program. This simple blend of high-quality ingredients can be amended with the grower’s preferred nutrient pack, can be used with either organic or synthetic nutrients (dry or liquid) and can be used in any growing conditions (indoor, outdoor, greenhouse). Crafter’s Mix is friendly mix to use and includes the microbes to make your nutrient pack more efficient and bioavailable to the crop.

 4. Biology for a Better Harvest


Whether growing in a water-only growing media, a self-formulated “build-it-yourself” soil, native soil, or used in conjunction w/ a liquid fertility model, biology is an essential variable in the growth system for increasing overall plant health and a bountiful harvest. From healthier root development to more oil and resin production, adding biology to your growing system increases nutrient uptake which can aid in higher yields. Our BIOACTIVETM Liquid Biology Bundle is an easy-to-use liquid biological program that rejuvenates your soil and aid in the plants phyllosphere microbiome’s capability to capture atmospheric gasses.  

BIOACTIVETM LiquiLife is a broad-spectrum liquid biological concentrate that preserves and delivers beneficial microbes in your soil. LiquiLife improves nutrient uptake, and helps to increase flavor, quality, and yield. BIOACTIVETM Liquid Supercharger infuses your soil with nutrients, protein, three sugars, fulvic acid, humic acid, liquid carbon, amino acids, essential nutrients to increase plant vigor, improve stress tolerance, nutrient absorption and uptake, and improve terpenoid and flavonoid profile. It supercharges your plants and your soil!

 In Conclusion: Because of the plant’s genetic ability of flowering/reproducing automatically, autos are an easy-to-grow cannabis variety that is for beginners and experts, especially when you’re growing in hand-crafted soil mixes with high quality ingredients. They cannot be manipulated compared to photoperiod plants, especially when it comes to topping, cloning, pruning, or extending the vegetation phase to increase the overall size of your plants. However, autoflowers have gained the reputation in the industry as a good option for novice growers, and cultivars are rapidly expanding to develop specimens that can compete with their regular photoperiodic cousins and mates. It’s important to grow autoflowers in high quality soil for the best grow results, and to stay one step ahead of your plant’s nutritional needs.