autoflower harvestYield, the amount of bud we get from our plants, is the most valuable measurement of how well and how efficient we run our grow operation.

The harvested and dried weight of our cannabis flowers is the main reason we are growing this plant so no wonder that people are searching for ways to increase yield and what are the best yielding plants. But to be frank, there is no one answer that fits all these questions and every grow operation is different so every plant will yield different amounts.

Of course, there are general guidelines like that regular autoflowers like Fast BUD #2 will typically yield far less than SUPER autoflowers like BIG BANG. But that also is not written in stone because you can grow a small yielding plant in nearly perfect conditions or get a bigger yield than from a SUPER autoflower strain in poor conditions.

So basically every growth is different and even growing in ideal conditions plants can have different yields because the genetics have a slight variation or just some random event slowed one plant down a bit at the seedling phase and it did not catch up with its siblings.

How is yield measured?

First of all, I think all of us know that cannabis yield is measured in the dried grams of buds a particular plant produces.

But these measurements can vary because there are two standards how seed companies rate plants. They are:

  • By the grams a single plant produces.

  • By the grams a plant produces in a square meter.

Because there are two measurements this can get a bit confusing. As most us know that how much a single plant produces is easily measured. But how to know how much grams plants can produce in a square meter?

Usually, seed companies grow 9 to 12 plants in a square meter area and then get their results. But they should be taken with a grain of salt because that yield will be only achievable under ideal condition and with many small plants. So think of these yield measurements only as a guideline to compare strains who are big yielders and who are not.

pineapple express autoflower budWhat affect autoflower yield

So what exactly can affect an autoflowers yield?

This is a difficult question with many answers and even the slightest variation can decrease or increase the total bud weight a plant creates.

But I will try to count as many things I can that can influence the yield :

  • Genetics: Every plant is a little different and you can’t get 100 % equal plants if you plant them from seed and because many of the strains available in the seed markets today are not 100 % stable you can get some plants that just don’t grow as huge as others from the same seed batch. This is because the crosses are not perfectly stable and it is best to go with an older more stable variation of autoflowers if you want uniform plants that all produce similar yields.

  • Light intensity & spread: Light is the plant’s energy source and how intense the light is and how well it is spread all over your autoflower matters a great deal. This is why you don’t get huge yields from CFL bulbs but can harvest more than 100 grams from a single autoflower below a LED light or T5 grow light fixture. The spread is also important because you can get more light from a T5 fixture to your light than from a single HPS or MH light source and more light means more yield!

  • Light position: Where you position your light is also important because a light positioned at a distance won’t transfer as many photons to your plant’s leaves as a light that is few inches away. Every light has its own sweet spot and you should always grow plants in that region where the heat is not too big but the light intensity is at it’s maximum.

  • Light spectrum (color): Not all light waves are equal and some light spectrums (colors) like the red and blue are more useful to plants than others. The right light spectrum will give you much greater growth and overall efficiency. There is also green light that cannabis plants do not use at all so any light source that produces less green light will be more efficient and will give you better overall plant weight. One more thing to mention in the spectrum section is that autoflowers require a slightly different light in their flowering phase than in the vegetative or seedling phases. And this can also increase the total bud mass because if you supply only the daylight Blue spectrum light plants can start stretching but if more Red light is provided you can get smaller plants.

  • Ventilation: Ventilation is crucial. You need to change the air inside your grow room because your cannabis plants will use up all the CO2  from the surrounding area around the leaves. And if this happens their energy uptake can slow down. Here comes in the ventilation system that circulated air inside the grow room and lets fresh air in from outside of the grow room and usually this air is full of CO2.

  • Temperature: Temperature is also a main factor that can affect your total yield as too low or too high temperature also decreases the CO2 intake or slows down respiration and that in fact again slows down growth and lowers total plant mass.

  • Nutrients: Nutrients are the plants food and they are responsible for every part of your weed plant development. Nutrient deficiency or overdose can have huge impact on plant growth and can even kill them completely if not treated properly.

  • Soil: The composition of the growing material is also a factor to think about when considering the end result. Soil that is too airy or light won’t hold roots completely and will damage them. Yet soil that is too hard won’t allow roots to penetrate it easily and your plant will need extra energy to grow those roots that could have been used for bud development.

  • Insects: Insects, mold, and other parasites can damage and ruin a plant while it is growing and you can get no yield at all. So be very careful when attending your plants and always wash your hands and tools so nothing can penetrate and infect your garden.

  • Grow room design: The design and shape of the grow room affect different areas from this list that include light height, ventilation, light efficiency, and temperature. So you need to carefully plan how you build your growing environment. Also think about how your plant will fit in that room and how many pots, fans and lamps you need. This also implies that you always need to monitor your humidity and temperature.

  • Training: Training your little green buddies can also increase their total yield because it allows them to get more light and you to maximize your growing space and increase the yield you can get from that particular space.

  • PH in the growing medium and water: PH is a vital measurement you need to take when you water your garden because low or high PH value locks out vital nutrient uptake and in the process again slows down growth.

  • Light cycle: Your growing light cycle can also increase and decrease yield because autoflowers don’t require the 12/12 light cycle to start flowering and it will only decrease the yield so a true autoflowering cannabis variety will do its best growth under continuous light and the 18/6 and 20/4 cycles will do considerably better than the typical 12/12 that is used for photosensitive marijuana plants.

  • Watering: Too much water or too little water can play a major role in the end yield. Both of these extremes stress your plant and it won’t grow as fast as it could have.

  • Pot size: Growing container size also determines what the end yield will be from your autoflower girls. Small pots are very inefficient and plants get root bound so they stop growing and you will get small yields. You need at least 2 to 3 gallons (7.5 to 11.3 liter) pots for autoflowers and more than 3 gallons (1.3 liters) for super autoflowers.

How genetics affect yield?

Genetics or plant origins can affect yield in many different ways as some strains are more resilient to harsh conditions and some are better at leaf growth. The possibilities are endless and each strain is unique but breeders tend to give growers only the best and most stable strains so you should at least get a somewhat even plant growth from the same batch of seeds. Yet if you would grow out 100 plants from a bulk seed package you will probably see some differences in them.

Genetics also influence yield because of the parents the particular hybrid was made with. All autoflowers are hybrids of some sort because the real and wild autoflowering cannabis variety has almost no THC so all the strains had to be bred to get that THC in them.

If the parents have had More sativa genetics in them then your plant will be more fluffy and will not have dense and heavy buds but if the indica genes are more than any other then you can get dense and huge colas that will definitely give you larger harvests.

Inside vs outside yield

The inside VS outside debate is always interesting and growers that do one or the other usually swear by their method and say that it is the best. But here is my take.

Both indoors and outdoors can be equally good for autoflower growing. However, you need perfect condition inside and outside to get maximum yield so stress in any of those environments will diminish yield and harm your plant.

As I mentioned earlier autoflowers are really fragile when they get stressed. Outdoors strong rains or cloudy days will stress the plants and therefore they will produce less yield. The same goes for inside as you can make some of your grow room conditions wrong and your plants won’t produce as much!

Small autoflower yield

Regular autoflowering plants are usually small and will yield somewhere from 10 to 50 grams per plant. But there are some exceptions that can yield up to 100 grams a plant but that goes into the SUPER autoflower territory.

Basically, if a strain flowers really fast and stays short you can’t expect more than 20 or 30 grams from it. But if it grows a bit longer or taller a 40 to 50-gram plant is achievable.

SUPER autoflower yield

Super autoflowers are a different breed and they can produce 200 grams a plant and more in perfect conditions.

These yields are amazing but that means these plants are also much larger and busier and you will have trouble growing them in small spaces so consider what yield you want and how much growing space you have.

How can you increase yield?

Increasing your autoflower yield is again a very broad thing to consider and all the things that affect your plant can be improved. So in theory, you can almost endlessly improve your plant production by tweaking your growing conditions.

However, usually, we want to put in the least amount of work to get the best plants so we tend to change only the biggest things like lights and nutrients. These two subjects are the main factors you can also look at when thinking about increasing your next harvest.

What can decrease yield?

The weight of your harvest can be decreased again by almost any of the previously mentioned things. But usually yield is decreased when some kind of stress has been endorsed on your plant. So try to keep everything stable and don’t change growing conditions too drastically so that your plants can adapt and grow to their full potential.

As you can see the cannabis yield subject is really broad and increasing yield is in every grower’s interest.

But before thinking of any growing conditions you need to get the best seeds and only then start tweaking and changing your grow room design and interior technologies to get that desired maximum yield.


    • Tnx! Hope you enjoyed the article, and if you have any questions send me an email or ask on twitter or just here at the comment section!

  1. Tokindaily on

    dude ve never grown autos before and in the beggining they are growing a lot up but not haveng a lot of leafs, anyway the older I got has like 2 3 days of life since germination and it is only producing the seconde pair of leafs … could you tell me if thats na healthy palnt or not and if not qhat should I do?

    • Hi,
      I think you are getting ahead of things and in the first few days autoflowers are mainly producing their underground root mass and not much above ground growth will be visible.
      Have you got any comparisons to reals trains or other grow experience?

    • Growing Girl Scout Gum Super Auto. My first Auto. I’ve been stress training, pop corning, monster cropping with good results on non-autos and getting good results. This Auto #1 popped on 10 Jan. It is tent grown. All growth factors same as its 3 sisters. 2-3-4 left au natural, no cuts, no bends. The simple stress of cropping the 2 sets of top nodes after the 1st cut have set it WAY back as compared to the other 3.
      SO ! I am unsure if it is the strain (G.S.G.Auto) or if this is typical of all ruderalis autoflowring strains.
      I’ll not crop or stress any more autos until I know more about this.
      In the meantime, #1 is starting to spread out due to that stress and it should be low and wide. I will grow a strong male and hand pollenate #1 to see if the seed produced make a new strain as good as the GSG Auto. About +8 weeks to go.

  2. wymxable on

    Hi, Midowo! Can u tell me how I can find out which strains are regular or super autowlowers? I have never seen such infos on seedbanks’ sites. It is really immportant thing to me bcuz Im going to try the scrog in my box. I would be extremely grateful to you for any ifnformation. Anyway, great job dude! It’s the most informative site I have ever found in the whole web!!!

    • Hi,
      I thing there is no way of telling which ones are real super autos and which ones are regular photo-sensitive plants before growing them. Usually seed breeders supply this info but you can’t be 100% sure till you trie them out.

  3. Good article!
    I think other side we should care about watering for plants. According to my experience, using some water gel (like potassium polyacrylate) can increase 15% yield at least.

    • Thnx for the kind words.

      I haven’t heard of potassium polyacrylate but will definitely check it out. Thnx for the info!

  4. Some of your information is misleading to new growers. For instance, you say blue light makes plants stretch and red light makes shorter plants, you have this 100% backwards man. Blue light makes plants shorter, and red causes them to stretch, you can find this out by simply doing a comparison grow of F5 seeds or identical clones underneath a Metal Halide and a HPS and you will CLEARLY see that you are incorrect.

    With autos, the more you can low-stress-train the plants and get them to stretch down, the higher they will yield. Period.

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