What’s the Difference Between Feminized and Autoflowering Seeds?

Last updated: 20 May 2022

autoflower vs feminized

Whenever you go to a seed shop, the first thing you’ll notice is that about half the seeds on offer are feminized and the other half are autoflowering. Experienced growers know exactly what this means, but it might be baffling for beginners. In this post, we’ll explain the difference between autoflower vs. feminized to help you make an informed choice.

The feminized-vs-autoflowering distinction isn’t exactly grounded in science. Rather, it’s simply a useful convention. Cannabis seeds can be feminized or autoflowering or both. Some of them are neither. To untangle this mess, one needs to understand exactly what it means for seeds to be feminized and what it means to be autoflowering, which is exactly what this article will cover.

What are Feminized Seeds?

What are feminized seeds

Feminized seeds means that the seeds’ genetics were manipulated in such a way that they produce only female plants.

Don’t forget that, naturally, cannabis produces two distinct sexes, so when you buy regular seeds, you will get both females and males and the ratio will be around 50/50. For those gardeners who only want to grow female buds to smoke, males are a useless ballast and are therefore discarded as soon as they reveal their sex. Moreover, males even harm your harvest because they pollinate female flowers and make them go to seed. As a result, you don’t get sinsemilla (buds without seeds), so the flowers are less fat, dense, and resinous.

The alternative to feminized seeds is regular seeds – the ones we’ve already mentioned.

What Does Autoflowering Mean?

While the invention of feminized seeds led to the first revolution in this industry, the emergence of autoflowers was the second and arguably even more important one. To be autoflowering means the ability of cannabis plants to start to flower automatically – when they reach the age of about 2-4 weeks from sprouts or a certain size (a certain number of nodes).

The autoflowering feature is a naturally evolved character, but it was only discovered in one weed variety – Cannabis ruderalis. This feral Siberian species has only a couple of summer months to rush through its whole life cycle, so it doesn’t waste any time. Breeders have used this amazing ability and crossed Ruderalis with various commercial varieties. Autoflowers are the result of this hybridization.

The alternative to autoflowers is photoperiod strains – meaning all the rest of the cannabis varieties that only start to flower when they notice the days get shorter. It happens at the end of summer outdoors or when the grower changes the light cycle to 12/12 indoors.

Pros and Cons of Autoflowering Seeds

Autoflowering seeds

Autoflowering seeds are a brilliant invention, and their benefits are overwhelming:

  • Outdoors, they can be planted at any time in the growing season and will finish in 70 days or less regardless of the light cycle.
  • Indoors, you don’t have to maintain different light schedules for vegging and flowering plants.
  • With more light hours in flower, autoflowers soak in more energy.
  • They don’t need complete darkness at night, so light leaks won’t disrupt budding.
  • You’ll get your harvest in record time.
  • The plants’ size is limited, which is great for small indoor setups or clandestine outdoors patches.
  • Thanks to their Siberian genes, autos are cold-resistant and hardy.

The main drawback of autoflowers is that the clock is always ticking for them, and whenever you stress or shock them, they won’t have time to recover and can stay small or even comically tiny.

Growing Feminized Seeds vs. Autoflowering

When people choose between autoflowering vs. feminized seeds, they’re really choosing between genetics that flower automatically and those that don’t, as most autoflowering seeds on the market are also feminized, meaning that they’ll only produce girls.

Choose so-called feminized (or, more correctly, feminized photoperiod) seeds if you’re okay with waiting for your harvest until fall outdoors or don’t mind switching to 12/12 indoors, or if you want bigger and consequently more high-yielding plants. Moreover, sometimes, a particular variety only comes in a photoperiod version.

Choose autoflowers for any of the reasons given above where we talked about the pros of autos. And if you’re new to this game and doubt you have green thumbs, growing a photoperiod feminized variety can be less nerve-wracking. Whenever your inexperience deals a blow to a seedling or a vegging cannabis plant, you can nurse her back to health and take all the time in the world doing it – and when she recovers, you can induce the flowering.

Autoflowering vs. Feminized: Yields

Because of their shorter life cycle, autoflowers tend to stay smaller and yield less than feminized strains. However, autos are so popular that the best minds in breeding are always working on closing the gap between autoflowering and feminized seeds in important ways, including yields. At least in indoor setups, many modern autoflowers can bring in the same yields per square meter as their photoperiod counterparts.

Autoflowering vs. Feminized: Harvesting Time

Autoflowers have a shorter vegetative phase and a shorter flowering time. As a result, they’re about 30% faster indoors than feminized varieties. Outdoors, the difference in speed can be astronomical. If you plant both autos and fems in spring, the former will be ready in around 70 days while the latter will only finish by around September or October.

Which is Better For Indoor/Outdoor Cultivation?

The answer depends on your goals and the details of your setup, but autoflowers are definitely less demanding. You can grow them successfully in smaller rooms with fewer bells and whistles. Outdoors, they’re great if you want a “quickie,” but if you don’t mind tending to your garden for a whole long season, you’ll get huge trees with pounds of buds from feminized seeds by fall.

For growers in colder climates with short summers and rainy falls, autoflowers are the only option. Feminized “late bloomers” will simply have no time to mature before bad weather comes and ruins them.


Are autoflowers less potent?

On average, they are. In the same genetic line, autoflower versions are less potent than their photoperiod originals. However, many state-of-the-art autoflowers are miracles of breeding and way more potent than many photoperiod classics of past decades.

What's better: autoflower or feminized seeds?

Autoflowers are better in terms of speed, manageable size, and demands regarding setup. Feminized seeds are better when you want bigger plants, high yields, and sometimes, more potent and flavorful smoke.

Autoflowering vs. feminized: which is better for beginners?

Autoflowers are more straightforward to grow than feminized plants. You simply have fewer things to keep in mind. They also let you get your first harvest sooner. However, if you make any serious mistakes, autos are less forgiving and often have no time to bounce back. With photoperiod feminized strains, you can always take your time before they get better. With autos, it’s often best to move on and start from scratch.

Is there a difference in weed quality between feminized and autoflowering?

This was a serious concern a couple of decades ago when autoflowering cannabis made its first appearance. Back then, autoflowers were bred for their speed and short stature alone and had little else to recommend them. However, by now, breeders have done such a great job that many autoflowers are as aromatic, tasty, and potent as any weed you’ve ever tried. On average, they’re still a little behind their photoperiod opposite numbers, but the difference in quality is too small for most newbies to notice.

Herbies Head Shop expressly refuses to support the use, production, or supply of illegal substances. For more details read our Legal Disclaimer.

Oops, no comments yet. Be the first one to give your feedback!
Add a comment

How to post a comment

Thank you for leaving a comment for us!

Your feedback will be posted shortly after our moderator checks it.

Please note that we don’t publish reviews that:

  • Are written in ALL CAPS
  • Use aggressive or offensive language
  • Promote other websites (include contact details or links)