Regular cannabis seeds will generally develop into both male and female plants.  If you’re unlucky, you may end up with the odd hermaphrodite plant.  You need to remove both males and hermies as quickly as possible.  Males don’t carry bud and you don’t want them fertilizing the females which do.  Hermies do carry bud, but it’s very low quality.  They also carry pollen and so can fertilise productive females.  Basically, they’re more hassle than they’re worth.  The best time to sex marijuana plants is during pre-flower.  This is when they first become identifiable as male or female. 

Beginner tip 

If you are new to sexing marijuana plants, you probably want to start with a maximum of five seeds.  Stick to the one strain, so you can easily compare your plants.  You also want to leave plenty of space in your growing room so you can physically move plants.  This will allow you to “sex in stages”.  In other words, if you’re sure a plant is male you can just remove it.  If you’re not sure, then you can separate your plants into “females” and “not sure”.  Keep them far enough apart that there is no chance of pollen from the “not sures” reaching the females.  Then you can work on definitely sexing the “not sures”. 

Bonus tip 

Statistics can play tricks on people.  In principle, regular seeds have a 50/50 chance of being male or female.  If you only sow one seed, then it can only be one sex or the other (unless it hermies).  If you sow more than one seed then you may or may not get a mix of genders.  The more seeds you sow, the more likely it is that you will end up with a mix of genders.  It is, however, not guaranteed.  You could still end up with all male plants or all female plants.  Remember this when you are sexing your marijuana plants.  Basically, go by what you see rather than what the statistics suggest you ought to have. 

How to sex marijuana plants 

Frankly, the easiest way to sex marijuana plants is to use feminized seeds.  If, however, you want to do it the “old-school” way, here’s what you need to know. 

Step 1 - Go online 

Look for videos showing the difference between a male cannabis plant and a female cannabis plant.  If at all possible, look for videos which relate to the strain you’ve chosen.  If you can’t find any, look for a comparable strain.  In other words, if you’re growing a strain which is 80% Indica dominant, look for someone else growing a strain which is 80% Indica dominant.  Then go and look for close-up images of the key parts.  Yes, it will be different when you do it yourself.  In fact the first time, you may find it a bit of a challenge.  Looking at online resources, however, can definitely be a big help. 

Step 2 - Stand back and look at your plants from a (bit of a) distance 

Before you get caught up in details, take a look at the bigger picture.  Male plants tend to grow quicker than females.  They also tend to be slimmer and have less foliage.  This is, of course, all relative.  A male Indica is never going to be as leggy as a female Sativa.  A female Sativa is never going to be as bushy as a male Indica.  That’s why you want to stick to one strain at first.  Then you can make like-for-like comparisons. 

Step 3 - Look for pollen sacks

Look for pollen sack for male plants

Pollen sacks look, quite literally, like tiny balls.  They can be seen with just the naked eye.  Having said that, a magnifying device can make the task a whole lot easier.  If you see a pollen sack, then a plant is definitely male.  If you don’t it may be female.  Alternatively, it may still be in the process of development.

Step 4 - Look for pistils 

Look for white pistils

In the pre-flowering stage, pistils are tiny white hairs.  They are virtually impossible to spot without a magnifying device.  Even with a magnifying device, it can be a challenge to see them at first.  Later, as flowering continues, the pistils will become both very colourful and very obvious. 


Step 5 - Clone the “not sures”

Take a cutting of the “not sures”.  Let it grow for a few days.  Then force flowering.  The sex of the clone will also be the sex of the host.  This trick is 100% accurate - as long as you keep accurate records of what cutting came from what host. 

What is a hermaphrodite cannabis plant? 

Hermaphrodite plants develop both male and female sexual parts.  Hermaphrodite weed is lower in both quantity and quality than regular bud.  Sometimes it’s still usable.  Sometimes it’s only fit for the (composting) bin. 

There are some strains which are frankly notorious for hermying.  Reputable seed banks will mention this in their descriptions.  You can also double-check with independent strain reviews.  These strains are best left to the most experienced growers. 

In general, most strains will only hermie if they are exposed to excessive stress.  The big five causes of hermying are: ventilation, lighting, temperature, hygiene and handling. 

Out of these, ventilation is usually the biggest issue.  The reason for this is that it causes so many other problems.  For example, poor ventilation means that your plants are too close together.  This makes it hard for them to capture sufficient light and easier for them to overheat.  It makes it harder for the grower to keep the growing room clean and easier for any problems to spread from one plant to another.  Last but by no means least, it makes it harder for the grower to handle the plants appropriately and so easier for them to be damaged. 

In short, if you choose a robust strain and remember your marijuana basics, then you should be able to avoid hermies.  The less experience you have, the more important it is to choose a strain with solid genetics.  Again, reputable seed banks will generally highlight strains which are particularly suitable for beginners.  You can also check online for independent strain reviews.