FastBuds seedbank #1 with 10426 diaries and a rating of Growdiaries 8.8/10 on GrowDiaries
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When do Autoflowers Start to Smell?

Growers love that unique smell, but watch out, it could get you in trouble!
13 June 2022
5 min read
When do Autoflowers Start to Smell?

  • 1. When do autoflowers start to smell and why?
  • 2. How to control smells in the grow room
  • 2. a. Carbon filter
  • 2. b. Odor neutralizers
  • 2. c. Ozone generators
  • 2. d. Strain selection
  • 3. In conclusion

Cannabis cultivation is still illegal in many countries across the world, growers indoors try to eliminate the smell but this can be tricky especially during flowering. Eliminating smell in small grows can be achieved with carbon filters or by having a good air circulation, while big grows will need more drastic measures such as ozone generators and more than one filter.

1. When Do Autoflowers Start To Smell And Why? 

That typical cannabis smell that all growers love comes from the production of trichomes. Trichomes contain cannabinoids and terpenes, and terpenes are responsible for the smell.

With autoflowers this happens between 4-6 weeks, depending on growing conditions and strain genetics. But the general rule is your plant won’t start to smell until it enters the pre-flowering stage.

When do Autoflowers Start to Smell?: Pre-flowering stage of cannabis

Pre-flower of a Cream Cookies Auto plant on week 5, courtesy of grower stealthassassin from GrowDiaries

Sometimes the smell can start as early as 3 weeks into the vegetative stage but it gets MUCH stronger once the plant starts to produce buds and you will definitely need to control it.

From the 4th or 5th week of flower production, the smell can become a little hard to control. As cannabis enthusiasts, we all know and love the smell of top-shelf ganja, but if you have never cultivated weed before you may be unaware of just how overpowering the smell can be from weed that is still growing (or drying, for that matter).

This smell can, and usually will be, much much stronger than anything you have encountered in terms of ready-to-smoke buds. That fresh flower aroma is truly a smell to behold, but even if you live in a cannabis legal area, it is an aspect of weed growing that many cultivators want to be able to control. 

Ok, how do we go about controlling the smell?

There are a few handy products on the market that are ready-made to help you with the job. If you are growing outdoors it can be a little tricky, but the smell coming off the crop will also be less intense than that of an indoor grow room. For indoor grows, there are a couple of key pieces of equipment you can use to help in masking any and all cannabis fragrances. We have already briefly mentioned a few options above, but let’s dive right in and take a deep look at all the options.

One thing to keep in mind is to never skimp on cannabis equipment. Sure, you can go online and find grow tents, carbon filters, fans, and whatever else for slashed prices. But, these are most likely inferior knockoffs that really won’t serve you. Take a cheap tent as an example. These will leak smells like nothing else, no matter how good the carbon filter is. Do yourself a favor and buy decent equipment the first time around, you’ll save a bunch of money in the long run.

2. How To Control Smells In The Grow Room

Carbon Filter

This is possibly one of the best methods of minimizing smell in an indoor grow. It’s a proven and tested method and works with grow spaces of all sizes. Carbon filters work by pulling odor and filter impurities from the air that is pushed through the filter by an exhaust fan.

When do Autoflowers Start to Smell?: Controlling smell with Carbon Filter

How does carbon filter work in your indoor grow room.

It is important there are no air leaks and ensure all the smell goes through the filter so that nothing but odorless air comes out. Carbon filters come in different sizes (depending on the capacity of your grow room) and can be found in any grow shop.

Odor Neutralizers

A cheap solution in covering up the smell is using odor neutralizers. Unlike a carbon filter, odor neutralizers don’t clean the air, these products are designed to mask unpleasant smells. Growers may use air sprays or incenses to try to mask the smell but it won’t be much effective.

Odor neutralizers usually come in the form of gel and have active chemicals, in order to maximize the potential you have to keep them active constantly. Since they work on the chemical level, you have to be careful, by placing them close to your plants because you have a high risk of altering the taste and smell of the buds.

The downside to these products is they have a short effective period and you need to keep changing them, some growers don’t even consider this as a plausible solution unless you have a really small grow space.

Tip: Nowadays you can find environmentally safe odor neutralizers but we still recommend investing in a carbon filter.

Ozone Generators

An ozone generator is a device that can be used as an air purifier removing contaminants from the air. Ozone generators are usually used in big grow spaces with a large number of plants. They were more recently introduced in cannabis gardening and they claim to be an effective way to eliminate odor, impurities, and even pathogen bacteria from the room.

When do Autoflowers Start to Smell?: How an air ozone generator works

How an air ozone generator works: the entire process takes less than 1 second!

Despite the high cost of the device, it comes with the huge downside being harmful to the environment and causing lung irritation. Ozone generators are even banned as a product in some countries so we recommend talking to your local grow shop before using one.

Strain Selection

This method isn’t really very effective, all autoflowers smell even though some may smell less than others. Choosing a strain with less odor may help in a small grow. Indica dominant strains with softer flavors and sweet terpenes as cookies and fruit, like Girl Scout Cookies Auto and Blackberry Auto tend to smell less.

Girl Scout Cookies Auto
4 out of 5
I grew my Girl Scout plant outdoors and the weather was mostly cloudy in flower with frequent rains. There were no issues with mold though.
Verified customer
Reviewed 13 November

But we all know every grower likes that unique cannabis smell, so in any case, we still recommend investing in an air filter and growing the strain you prefer, regardless of smelling too much or not.

3. In Conclusion

Regardless of the size of your grow operation we recommend investing in an air filter. The price can vary, starting at around 50 bucks and going up to 200 or more. This is the only way to be sure all the smell is eliminated thus avoiding problems with neighbors and the law. 

13 June 2022