What are Autoflowers?

Spawned from the little known species Cannabis Ruderalis and crossed with your favorite Indica, Sativa and/or hybrids of both, today’s "autoflowering" hybrids (aka "autos") offer a straightforward growing process with some great genetics available from leading edge seed breeders these days.  

When dealing with regular cannabis seeds, plants will go through a vegetative state until you induce flowering by shortening the "daylight" period (usually after 3 months indoors and up to 7 months outdoors which occurs naturally via shorter days).   When growing indoors, you must switch to a shorter twelve hour light cycle to begin the flowering stage. Autoflowering seeds don't need this light cycle change — they will automatically kick into flowering after 3 to 4 weeks of vegetive growth (depending on the strain you are growing) with no change in lighting.

You can easily go 20 hours of “lights on” and 4 hours of darkness/sleep cycle and just leave it alone. The extra light alone will produce a bigger plant. With autoflowering seeds, this process happens all on its own and can be a great method for growers looking for a speedier harvest from their plants. In addition, almost all Autoflowering seeds sold are feminized—meaning every seed should produce a female plant. Great for the novice, but viable for any grower as the strains these days (as of the year 2020) are fantastic. Although there is some disagreement in the scientific community regarding Species or Sub-Species, we don’t address that here. We will leave that to the scientists to sort out. 

NOTE: Some growers go full tilt “boogie” and leave the lights on 24/7. We believe that every living thing needs some rest, and it can be detrimental to the plant's immune system and needlessly over-stresses them. This is a topic of much debate, but this is our position on light cycles for autos: we prefer 18/6 or 20/4.

Autoflowering 101: How to Grow Autoflower Plants

Growing autoflower cannabis plants is quite possibly the easiest way to grow. That being said, there are many failures as people try to follow "typical" procedures for regular (aka "photos" or "photosensitive") plants.  People will read online about how to defoliate, lollypop, crop, germinate, transplant and clone cannabis plants, and then will attempt that with an autoflowering hybrid. 

Experimentation is ongoing, but with a plant that literally is ready to harvest in as little as eight weeks, you can imagine what damage (stunting, even killing the plant is possible) interrupting that cycle might cause. With drastic stress involved in cropping, etc., the plant doesn't have enough time to recuperate and "bounce back" due to its incredibly shortened growth process.  In fact, autos also don't delineate "veg" from "bloom" quite as clearly as with photos  — autoflowers will start flowering while still growing, with more overlap during its transition. 

That being said, in general, autoflowering strains take the “guesswork” out of how long you should leave your plants in their vegetative state and when you should — or want to — switch your light cycle to twelve hours of light to induce the flowering phase. In addition, the complete flowering cycle is included in the “time from sprout to harvest” as opposed to adding another 8 to 12+ weeks of flower growth time to your schedule. With a proper set up and the right grow protocol, autoflowering cannabis plants can yield impressive results in regards to both quality and quantity of buds. With the right set up and protocol, 4 to 5 ounces per plant, of very high quality bud, is very achievable.

As stated, Autoflowering feminized seeds have a quick growth cycle and naturally deliver faster turnaround times, making the home grower a happy camper with more frequent harvest dates. Faster growth cycle means you'll have a timely harvest, and more harvests means more buds. You could conceivably get 5 or 6 harvests per year!

Autoflowering strains are a great way to get started with growing your own cannabis, or something new to try for a seasoned grower. Seed Banks list the Top 10 “Autos” and typically provide THC%, CBD%, medical use recommendations, yield estimates, and more.

FYI: You can typically get higher yields than published using the latest in grow equipment, latest techniques and protocol—like low stress training. For instance, just switching to a cloth pot will increase yield as the roots never get “root-bound.” Plant the seeds directly into the pot of soil you are going to harvest them from for best results. Keep the seeds hydrated (start by soaking the entire pot of soil) and they should sprout in 3 to 5 days.

Autoflower Nutrients and Schedule

Autoflowering plants naturally grow in soil. Unlike the popular methods with traditional photos, it is not recommended to germinate seeds separately (in a wet paper towel or a smaller Solo Cup style container) and then transplanting them later to a larger container once they sprout. Again, the cycle is so fast, that each stage of development can whiz by in a matter of days, and we don't want to disrupt that or we'll get subpar results.

It is also not good to grow these hydroponically. In fact, a cloth pot with a large water collection saucer is akin to hydroponically grown cannabis as far as the roots are concerned—i.e. many of the same benefits are achieved in a soil medium. Since autoflowering cannabis is a smaller plant and their vegetation periods are much shorter, you do not have to feed them quite as much—if at all. A good organic soil mix should supply all the nutrients you need for 75-90 days. That being said, some strains will use up various nutrients faster than others, so watch for color changes during your grow and act accordingly. A note of caution: use nutes sparingly, no matter what the bottle says.

The first nutrients to be used up are typically Nitrogen, and the least invasive nutrients are organic. Iguana Juice from Advanced Nutrients is a reputable brand. Your plant will need to access nutrients immediately, as grow times are short and microbes have less time to develop in the soil. Usually, good soil mixes have plenty of beneficial microbes, but you can always add more good microbes. Mykos (a specific brand of Mycorrhizae) being possibly the most important, as it will help strengthen the plant's natural immune system and push the limits of root growth — which, in turn will also help produce larger plants.  Although most important during the vegetive cycle, with some strains Nitrogen may also be needed during flowering. This is why nurturing your plants is always better than just letting them grow on their own — be it in an automated system, semi-automated system, non-automated system, tent or outdoors. Outdoor autos will always have lower yields than indoor grows due to longer light ON cycles indoors (i.e.18-20 hours).

Other great nutrients (if needed) for your autoflower strains are phosphorus, magnesium and potassium, these both help to promote growth in these types of cannabis plants.

Autoflower Light Schedules

Autoflower cannabis plants are great when it comes to light.
A) They do not require a change in lighting time to induce flowering.
B) If you “disturb” them during the sleep cycle, they don’t care.
C) These plants will automatically flower no matter the light schedule they are on.

This means you don't need any light deprivation set ups outdoors or supplemental lighting indoors. If you grow outdoors, your yields will naturally be smaller as in the US, we don’t get 20 hours of sunlight anywhere. Also, they can grow in colder weather than regular cannabis due to the genetics of the Ruderalis species hybridization. Cannabis Ruderalis hails from Siberia!

More light = larger plant = more buds! They will grow bigger and faster than their outdoor counterparts. These plants thrive on light to grow ultra-fast in their autoflowering cycles, so give them at least eighteen hours of light to maximize harvest yields.

Autoflower Grow Cycle and LST (Low Stress Training)

As stated, during the first part of the autoflower grow cycle you can expect a 2-3 week vegetative state. This is prior to flowering and is where you will want to do any stress training. Avoid causing too much stress on the plant and make sure it is truly low stress, or the plant could go into shock. This can cause stunting and take a toll on maximum yield. All that being said, up until flowering, the plant (and all stems) will be very pliable. This allows bending every which way to open the plant, which in turn gets more light deep into the canopy.

You will want 1/4” diameter bamboo (or similar) sticks and 10 to 12 inch plastic zip ties or twist ties, to train plants. Once flowering starts in earnest, it's best not to get too aggressive with LST—the plant will get less and less pliable as it gets deep into flowering and you can easily break a stem during bending at this stage. If that does happen at any point, tape it up—masking tape, painters tape, etc… works fine (as long as some hemp strands still connect the broken branch you will probably save it).

In any case, you want 95% of your training done no later than the first 3-5 days of flowering. Stress training is part art and science. The idea is to intervene in the natural growth pattern (like a Christmas tree) and make it more like a bush or hedge—creating more tops and yield by training the plant to grow like a bush or hedge with multiple tops with similar heights per branch.

Stress like this will cause the plant to produce more growth hormones, which equals more yield. LST in not the only factor in regards to higher yields, but is an important part of achieving the highest yield possible. There are many articles specific to this on the web and in this blog piece we just want to discuss what it is and what it achieves but this is not a LST focused article.

Flowering is a very exciting time for growers. They get to see their plants begin to bear "fruit" so to speak. This quick process allows for about a 8–10 week turnaround on most grows. Fantastic!

NOTE: There are 12-14 week strains, but for your first grow try a 8-10 week strain. You will be happy you did. It’s good experience and may just be what the strain calls for anyway.

How to Tell When It’s Flowering

The best way to tell when any cannabis plant is flowering is to look at the nodes and tops on each stem—including the main stem. If you are seeing what look to be white or opaque hairs coming from the tops of the stems, then it's flowering. You may even be able to start to smell hints of your autoflowering strains (the Terpenes / Aroma) as the plant begins to grow its buds. Skunk Indicia is called Skunk for a reason... Even Banana will smell like the fruit.

You can also begin to look for the cannabinoid crystals themselves (trichomes). This is a great indicator that your plant has begun to flower. For autoflower plants, time can be a good rule of thumb to go by as they usually begin flowering after one month. Ninety day strains may be a bit longer.

The coolest trait with Autos may just be that the flowering process is automatic. This takes out a lot of the “guesswork” and/or the precise “when to induce flowering” out of the equation in regards to when or “if” your plants have begun their flowering phase. A good magnifying glass comes in handy right about now. You can get small 10X to 100X magnifiers — with a light! on Amazon for $10- to $15 (and we think they're a great investment).

When to Harvest

Autoflowering plants are highly regarded in terms of fast harvest times. Usually it takes about eight to ten weeks from sprout or a autoflowering cannabis plant to reach maturity and be ready for harvest. You'll be able to see the beautiful colas standing tall above the foliage. Some strains develop long colas (a collection of buds all along each stem) and others will have one large bud at the end of each stem—or secondary stems—variations of these themes will be seen as well. The smell will also be much more concentrated and should reflect the seed’s genetics as advertised, and less like fresh cut grass, as the plants mature and become ready for harvest, the Terpenes (be it citrus, berry, pine or many other aromas) cut loose. It will smell up your entire house if you don’t have a proper growing room or enclosure and a carbon scrubber to remove orders before they reach the exhaust fan.

When harvesting your autoflowering plants, we recommend a “wet trim” (trim off all leaves without “sugar crystals” while the plant is still in the ground/pot), a few more days of growing under lights (4-5), and when ready, cut the entire plant down at its base. You can hang the entire plant to dry or cut individual branches. Some growers opt to leave the buds on the lower levels of the plant to mature a little longer while you trim and cure the buds that come from the larger cola. The idea here is that if you remove the top parts of the plants first that have had the most light, the lower levels of the plant can then get more direct light and mature in a much more hearty way. This is a better technique if growing “regular” strains (not Autos). However, it can be done with Autos, but in reality should not be necessary if you have trained the plant properly and literally “tuck” your large fan leaves along the way so other tops can get more light, the entire plant should be ready to harvest all at once.

More Information about Topping/Pruning/Cropping and Cloning Autos

“Topping” (cropping / pruning) can be a critical part of the process with “regular” cannabis plants (i.e. non-autoflowering), but the process is different for an Autoflower. Although experienced growers experiment with cropping, we don’t advise cropping or pruning an autoflowering cannabis strain—and as stated, never transplant an “Auto”. Their lives are so short that any radical interruption of the grow cycle can stunt or completely stop the plant from maturing. Cloning is another no-no for these strains for obvious reasons. If you do decide to cut/crop/prune/defoliate/clone Autos, you will most likely erase all of your nurturing and progress, and may even kill the plant. As stated, since the growth periods of autoflowering cannabis strains are so short, it's important to avoid harming/shocking the plant and stunting growth (or worse).

LST Autoflower (Low Stress Training) “explained”

Low Stress Training is one of four or five “tips and tricks” that, together, greatly increase yields. The method known as LST involves gently bending over cannabis stems while the plant is in veg mode. This is done in order to create more surface area to create a more vertical grow scenario. The main top should also be trained or your light will be too far away from the sub branches. The idea is to get all stems to the approximately the same height via LST. This allows the light to be as close as possible to all tops created via this technique. Avoid having the light too close as you don’t want to burn the plant. Conversely, if the light is too far from the tops they will stretch for the light and you will end up with spindly plants and low yield. The very act of stress training will cause the plant to release growth hormones—making more stems, tops and leaves, which equals more premium flower at harvest.

Can You Clone Autoflower Plants?

This is debatable. We do not recommend cloning Autos. However, as stated, some growers believe that it’s possible. Think about it logically.  If your plant is 3 weeks old and you clone it (just prior to flowering), the results from the clones will be miniscule. They will be about 3 inches tall and a week or so later begin to flower. You will end up with a bunch of 4” inch plants, minimizing your harvest versus if you had just followed our protocol. Also, you may kill the mother in the process, from shock, and she won’t have many tops left so why bother? 

Autoflower vs Photoperiod

Although confusing at first, the differences are really quite simple.  Photoperiod plants rely on changes in light cycles (indoors or out) in order to “know” when to flower. “Photos” (regular strains like C. Sativa / C. Indica and crosses of the two) will stay in the vegetative stage of growth indefinitely, or until the light changes sufficiently to induce flowering. This is typically twelve hours of light on and twelve hours lights out—uninterrupted.

C. Sativa can grow to 20 feet in height. C. Indica 5-6 feet. Crosses in-between depend on gene dominance but 10 feet is not uncommon outdoors. Autoflowering strains are hybridized in such a way that the plant will automatically begin to flower after it’s been growing for a certain amount of time, hence the term “Auto.”

Autos all include C. Ruderalis genes and rarely get over 3-3 ½ feet tall. The yield for Autos is typically less because they are smaller plants. That being said, there are plenty of tips, tricks and methods for producing higher yields from smaller plants as stated elsewhere in this article.

The decision to choose autoflowering or photoperiod strains will come down to personal preference and experience. Autos are often considered a good place to start for novice growers, because of their quick consistent grow cycles. Techniques such as non-cropping stress training, and in many cases equivalent THC content make it a no brainer for the novice. Many first-time growers choose this option. That being said, nowadays, there are plenty of autoflowering strains which are rewarding to even more experienced growers.

Vincent Bitetti is the President and COO of Green Goddess Supply, and the original inventor of The Armoire -- the firm's unique personal home grow system that is tuned for best results with autoflower strains.