worried girl sadly looks at her autoflower plant

Having trouble getting your autoflowers to flower? Maybe it is your first time growing with autos and you need to learn more about what it takes to get them budding. Or perhaps you are experienced with these strains and just need some helpful tips to get you back on track.
No matter what your situation may be, we have got you covered. Let us dive into more about autoflowers and how to get them to flower properly.

When to expect autoflowers to start flowering

Autoflowering strains are genetically bred; they’re a product of cannabis ruderalis. Ruderalis strains are known for their fast growth cycles -- and autoflowering strains are no different.
In contradiction to their counterparts, photoperiod strains, autos will flower based on their internal clock. With that in mind, typically your autoflower strains should be flowering within 5 weeks.
Once your auto plant has begun to flower, after a 2- to 4-week vegetative period, your plant could be ready to harvest as early as 7 weeks.

worried girl sadly looks at her autoflowering plant

Why your autoflowers aren’t flowering - and what to do

Autoflowers are some of the easiest types of cannabis strains to grow. While they are easier, it can still take some tinkering to get them to flower appropriately. Let’s look over some of the most common culprits that could make autoflowers not flower.

1. The strain is taking longer than expected

Like with all cannabis, every strain has its specific necessities. Autoflowers are no different. With autoflower strains, generally, you are given a range in which you can expect them to flower.
Sometimes, though, that range just may be off -- but try not to get discouraged! These things happen with all types of strains and it is certainly possible to find and fix the issue. Fortunately, the issue might simply be that it’s going to flower in its own time.
If it is taking longer than you were expecting for your autoflower to flower, double-check the range. You might even try researching the strain outside of the seed bank that you got it from. Consulting fellow growers can also help you pinpoint when it will start to flower.

2. It could need more (or less!) light

Even though most autoflowering strains do not require strict lighting cycles, there are a few that are the exception. Your strain could be more temperamental and need either more or less light. And if you’re finding that your cycle isn’t producing flowers, it might be time to reconsider its current light schedule.
You’re not alone, though -- some growers have reported similar issues with their autoflower strains. Most suggest that placing your plant on a 12/12 cycle might do the trick. There are even others who tried a 13/11 and started seeing buds forming by the end of the week.
However, be sure to keep in mind that if you do decide on changing your light cycle, do it gradually. A drastic change in the lighting period can stress your plant and further complications.

worried girl sadly looks at her weed plant

3. You’ve got a stubborn autoflower strain

You may have had luck in the past with your autoflowers growing and producing quickly. And with all your experience you’re still not sure why your current strain isn’t flowering.
This is when it’s time to do some research on your particular strain to better understand it as a whole. Some strains are just picky and will flower when they want to. As mentioned previously, each strain is different.
So if you’re able, take some time for some thorough research regarding your strain. We’re positive you’ll find out more about the strains' tendencies and possible needs to help get the plant back on track.

4. When it’s something else

While autoflowers are easier to grow and require “less” maintenance, sometimes you can just get a super stubborn autoflower strain. And if the above topics are all things you’ve considered or tried, here are a few other factors that could be affecting your plant:


Whether you’re a new or experienced flower grower, a common mistake that is overlooked is overwatering. The reason why overwatering your plant can become a problem is because it can lead to issues like:

  • Nutrient deficiencies
  • Root problems
  • Slow growth fungus
  • And, -- you guessed it -- slow flowering

Avoid water on a fixed schedule, which can be a quick-fix solution if you experience any of the issues listed. It is recommended to water at random and ensure the soil is dry before watering again.

worried girl sadly looks at her cannabis plant

pH Level

Another leading factor in slow flowering for autoflowers is incorrect pH level. If you are experiencing slow growth rates, it could be that the pH value in the nutrition solution is incorrect.
For example, if you’re growing your auto in soil the optimal pH range is between 6.5 and 7.0. So depending on your growing method, be sure to check what pH range is best suited for that particular method. We can recommend reading our blog; best soil for autoflowers for more in-depth info on soils.

Nutrient deficiency

One more thing to consider if your autoflower isn’t flowering on time is a possible nutrient deficiency. To steer clear of this issue be sure to check the recommended dosage for your autoflower.
Proper use of nutrients is the best way to ensure a healthy plant. And for your nutritional supplements to be effective they must be paired with the correct light intensity. So if you’re growing under sunlight, it is important to administer the right nutrients and the appropriate amount.

Unreliable seed bank source 

Sometimes, it’s not you -- it’s where you got your seeds from. Unfortunately, not every seed bank online is guaranteed to be reliable.
An easy way to avoid this is by purchasing your cannabis seeds from a trusted source, like Amsterdam Marijuana Seeds. Since ‘96, we’ve guaranteed our seeds have a high germination rate when following the instructions in our Grow Guide. If you don’t have a good germination rate after following our instructions, we will replace your ungerminated seeds.

Final thoughts on autoflowers not flowering

We’ve covered quite a bit of information today, and that may make it feel overwhelming. We assure you that when it comes to auto-flowering strains, once you identify and fix the issue, you will start seeing positive progress.

With that in mind finding a solution can be difficult with all the information available on the internet. So we took the time to provide you with this simple guide to save you the effort. We hope that you have found it to be informative and helpful. And we wish you luck on your growing journey!