Autoflowers, as recommended by seasoned growers, grow best when given light between 18 to 24 hours per day but there are scenarios that a grower also needs to provide only 12 hours of light on a given day. In this article, we will try to explain the details behind the autoflower switch to 12/12 light exposure and when they are ok or not ok to use.

Firstly, we need to emphasize that growing autoflowering cannabis plants on a 12/12 light schedule or autoflower 12 12 from seed to harvest is perfectly fine and can still definitely produce high-quality buds but considering that they will be only receiving a lesser amount of light, this will result in slightly smaller marijuana buds in comparison to cannabis plants grown under a 20 to 24 hour light exposure schedules.

Why perform an Autoflower Switch to 12/12?

The big question is can autoflowers grow under 12/12? Well, the answer is also a BIG Yes! In reality, there are a lot of reasons why a grower would end up giving a 12 hour light cycle to their autoflowering cannabis plants even though at best they thrive better under an 18-24 hour light exposure.

Here are the Common Reasons for an Autoflower Switch to 12/12;

Flower Room for Autoflowers – If you are growing regular seeds together with autoflowering seed and want to get your autoflowers plants to bud ahead of the photoperiods then you can move your autoflowering plants in a Flowering room. You can grow your photoperiods and autos by starting all of them on a 24 hour light cycle and then doing an autoflower switch to 12/12 when you want your photoperiod plants to start to flower. Autoflowering plants will not be affected by the changes in the light cycle contrary to the popular belief that this change will increase hermaphroditic effects.

  • Autoflower Outdoor Growing – If you are growing autoflowering cannabis plants outdoors either in autumn or spring when the natural light cycle is at a 12/12 ratio then this won’t affect your autoflowering plant’s growth and development overall. An autoflowering 12 12 light cycle is ample enough to allow optimal growth on your plant but then again, this may not produce buds that are as robust as those autoflowers grown on longer daylight.
  • High temperatures during the Day – If you are growing in a climate that has hot summers then you may want to use your grow lights at night and do an autoflower 12/12 light schedule indoors when the sun is down to give your plant an ambient cooler climate. In this scenario, you can still get some excellent buds even if you only use a 12 hour light schedule at night giving the plant a total of 24 hours light exposure including the 12 hours of natural light during the day.
  • Lowering down power Costs– If you are growing on a budget then you can do an autoflower switch to 12/12 reduced from your 24 hour light cycle to save electricity and lower its costs to half. This will still ensure you with excellent buds. But always do this with care as some autoflowering marijuana plants will usually take longer to mature with this light schedule so your grow time may still make it equivalent to the same power usage in reaching the ultimate goal or even so compromise the yield you are expected to harvest.
  • Bad Genes– If your Autoflowering plant doesn’t autoflower under non-stop light exposure after a 3 to 6 week period then it is likely that you got a seed from a bad batch with bad genetics. Doing an autoflower switch to 12/12 can trigger the plant to its flowering phase once the plant is matured physically.

As presented here, you can easily notice that there are a few good reasons why you want to perform an autoflower switch to 12/12 on your autoflowering plants but these do not come free and may result in some disadvantages to it.

Autoflower Switch to 12/12 Disadvantages

  • Excessive Stretching – If your autos only receive 12 hours of light a day with an equivalent dark period can cause your plants to stretch out excessively. Due to this, you will need to get your Autoflowering Cannabis plant as close as you can to the light source as possible when they are one and the same principle applies during the dark period that you must give them total darkness at night so that the plant will not stretch in search of this resource. An important note during the dark period is to avoid any light leaks that can complicate the signals within your plant’s internal system.
  • Slow Growth – Naturally if you provide less light to your plants they will in turn grow slower and won’t produce as much stalks and branches compared to those that are exposed longer. With this, your plants will end up smaller with fewer stalks and leaves plus less dense buds.
  • Less Yield – Overall when you provide less light to your autoflower plants they will reciprocate as well with less yield and this is truly a huge drawback for a lot of growers. But since having a 12/12 light schedule as an only choice and even less harvest from only growing a single plant. Surely you are still going to get some buds and maybe you can grow more plants on your next grow to compensate this drawback.

The most recommended light cycles for autoflowers are growing using a 12/12 from seeds or doing an auto flower switch to 12/12 from a 24/0 when the plant reaches its flowering phase.

  • 12/12 from the beginning – If you are developing autoflowers in your flower room, at that point you can expose them non stop under a 12/12 light/dark cycle however that will create the most noticeably bad outcomes as your plants will get a minimal measure of light.
  • 24/0 to start and autoflower switch to 12/12 – The most ideal alternative, if you need to utilize the 12 hour days, is to begin your plants under 24/0 or 18/6 while they are in their vegetative development stage and afterward change that light cycle to 12/12 when the first pre-blossoms show up. This will give your automobiles the most measure of development and the yield won’t endure that much.

What’s more, there are additionally some more intriguing light sheds like 14/10, 14/8, 13/11 (light/dark) that are used on photoperiod plants and where autoflower has been growing. In any case, I don’t consider them to be in these schedules as they don’t deliver more buds or if they do, at that point the thing that matters is typically minuscule.