“A single hermaphrodite can pollinate an entire grow room, rendering the cannabis flowers useless.” Learn more about hermaphrodites in the world of cannabis here. This is what you need to know to distinguish Male, Female and Hermaphrodite cannabis plants in your garden or grow room – and avoid seeds in your harvest. As every grower knows, cannabis is a dioecious species, meaning it produces some plants that are exclusively female and others that are exclusively male. However, because mother nature loves to break her own rules, some cannabis plants actually contain both male and female sexy bits, and are the …
Hermaphrodites: A word derived from the names of the Greek deities Hermes and Aphrodite; hermaphrodite is meant to convey the presence of both sets of reproductive organs. Cannabis, as some unfortunate growers may know, can develop this trait if stress occurs in sufficient quantities. A single hermaphrodite can pollinate an entire grow room, rendering the flowers useless. Light stress is the most common culprit, in which light leaks and broken timers can spell disaster! Check for any holes in your sealed grow room, and ensure timers are operating correctly to spare yourself this pain. However, hermaphrodites are the objective for some gardeners. Hermaphrodites are an essential aspect for the production of feminized seeds. In this case growers will spray a solution of colloidal silver on their plants during the first weeks of the flower cycle. The silver solution interrupts the production of female reproductive organs leaving a hermaphrodite. These plants are then left to self-pollinate and produce seeds that are 99.9% female, while maintaining the genetic traits of the parent.
How To Spot: Male, Female and Hermaphrodite Cannabis Plants
You don’t have to be an expert on the plant to at some point have encountered the term ‘feminized’ in relation to cannabis seeds. As the name suggests, this means cannabis plants can be either female or male and in some cases have both sexes. This is what you need to know to spot Male, Female and Hermaphrodite cannabis plants in your garden:
Male Or Female Cannabis Plants
Before we dive into the more complicated matter when it comes to sexing a cannabis plant, let’s start with some basics. Cannabis plants are so called ‘dioecious plants’ (‘di-‘ is ‘two’ in Greek; ‘oikia’ means ‘house’). This means they produce either male of female reproductive organs, known as the flowers. In contrast to ‘monoecious plants’, which produce two different types of flowers on the same plant.
The cannabis plants most consumers know and love are often female. As these are the plants that produce the smokeable flowers – the dried buds – but which can also be grown at home. These weed flowers, buds, or ‘colas’ are covered in trichomes / resin which holds the plant’s active components, like cannabinoids and terpenes. Male cannabis plants however are less popular with consumers, as their only task in life is to release pollen into the air.
Feminized Cannabis Seeds
When pollen from a male cannabis plant reaches a female cannabis flower, the female flower will start producing seeds with traits from both plants involved. That’s great for growers that like crossbreeding strains and develop their own cannabis varieties. But if you’re growing for your personal consumption, you might want to avoid pollination. Not only do seeds add a harsh taste to your smoke. Producing them also takes a lot of energy from the plant. Costly energy that should rather be put into the development of cannabinoids like THC and CBD.
The best thing you can do to guarantee you’ll grow female cannabis plants, is to purchase feminized cannabis seeds. In contrast to regular cannabis seeds, which will grow 50/50 males and females, feminized seeds guarantee for 98% to grow into female cannabis plants.
So even if you use feminized seeds, it is advised to keep a close eye and determine the sex of the plant as soon as you can. As there’s always a small chance at finding a male plant in your garden which could screw up your harvest, or for the plant to turn from female to hermaphrodite and develop both sexes on one cannabis plant; as we’ll explain later on.
Female Cannabis Plants
The sex of cannabis plants can be determined by looking for the first signs of bloom on the plant. These are visible a few days to a week after you switch your light to 12/12 and give your plant the sign to switch from the growth stage to the flowering stage of its life cycle . Outdoors, the same signal is given by nature as soon as the days grow shorter than 14 hours after the summer solstice.
Female cannabis plants are easy to spot once they start showing the first signs of flowering
Female weed plants are distinguished by the development of bracts with small white hairs (stigma’s) on their nodes. A node is the part of the plant where branches and leaves emerge from the stem. After a while, the female plant starts pushing out more and more of these hairs until they swell up from the bottom up. This means the plant is now forming ‘calyxes’ that eventually stack up to become the flower as we know it.
Pollination And Seeds
These ‘calyxes’ remain empty as long as the plant is not pollinated by a male plant. When it does get pollinated, these calyxes will fill up to hold and protect the plant’s babies: seeds. It is even thought that the resin on weed plants serves only that purpose in nature: to protect the plant’s offspring from burning in the sun.
Discover our Feminized Chocolato cannabis strain (White Choco x Gelato) here!
Male Cannabis Seeds
Male Cannabis Plants are recognized by the formation of pollen sacs on the plant’s nodes. This happens around the same time as female reproductive organs should be forming. Although female plants tend to develop their reproductive organs a bit faster. Luckily, these male pollen sacs can be distinguished pretty easily. As they look like small balls hanging from the side of the plant; instead of the upward facing hairs from the female plant.
Male Cannabis Plants form small ball-shaped pollen sacs on their nodes
When left to grow, these balls will eventually open up like a flower and release pollen into the air. As we’ve explained, this pollen is only interesting when you’re trying to make your own strains or seeds. If you’re not making seeds, make sure to remove every male plant from your garden or grow room before this happens. Do it with the upmost care, as rocking the plant could force it to release the pollen.
Hermaphrodite Cannabis Plants
The first paragraph of this article explains cannabis plants grow only one set of reproductive organs. Although there is still a ‘but’ to this. Because there always remains the possibility that female cannabis plants form male reproductive organs too. This usually happens when the plant(s) experience excessive stress. And in times of stress, they try to guarantee the survival of their species. Cannabis plants can do so by turning hermaphrodite, or ‘herma’ in grower terms.
Hermaphrodite cannabis plants develop both female and male reproductive organs
Because when cannabis plants turn ‘hermaphrodite’, they do so in order to pollinate themselves. Turning hermaphrodite is an evolutionary strategy of cannabis plants, designed to save the species in hard times.It allows the plant to produce seeds no matter what; even when there are no males around (for example, because the source of the ‘stress’ killed off all male plants).
How To Prevent Stress From Turning Female Cannabis Into Hermaphrodites
Some cannabis strains are more sensitive to stress than others. Stress can arise from a number of sources, from overly enthusiastic pruning and topping to environmental factors like excessive temperatures, water shortage or surplus, soil acidity or overfeeding and lack of nutrients. It is good to know that cannabis is called a ‘weed’ for a reason: this is a hardy species with great natural resilience. Still, most cannabis seeds you can order online are crossbreeds cultivated for specific traits like taste or THC content. Years of crossbreeding and hybridization have created some strains that are more prone to stress than their natural ancestors.
When growing strains that are sensitive to stress, growers run a risk of their cannabis plants developing hermaphroditic traits – like the well-known Original Glue (Gorilla Glue #4). In our online seeds catalogue, you’ll find certain strains that are particularly resistant to stress.
Removing Sex Organs From Hermaphrodite Cannabis Plants
If for whatever reason you do spot hermaphrodite cannabis plants, all is not lost. You just have to act fast and be cautious. To avoid hermaphrodite cannabis plants from pollinating themselves, carefully remove the male reproductive organs that form on the nodes. You can do so by gently taking a pollen sac in between two fingers and twisting/pulling it off. Wash your hands thoroughly before you go near your female plants – you don’t want to cause accidental pollination because of your dirty fingers! This way you can still have a satisfying harvest from any hermaphrodite, without having to pluck the seeds from your buds.
TIP: If you want to try and create your own unique strains, you can learn more about growing regular seeds in this blog.
TIP: For anyone trying to avoid raising hermaphrodites, check our info on the benefits of buying feminized seeds here.
What To Do With Hermaphrodite Cannabis Plants
As every grower knows, cannabis is a dioecious species, meaning it produces some plants that are exclusively female and others that are exclusively male. However, because mother nature loves to break her own rules, some cannabis plants actually contain both male and female sexy bits, and are therefore known as hermaphrodites. While this is fairly rare, most growers will come across hermaphroditism in their crop from time to time, so it’s important to know how to handle these plants.
As we explained in a previous post, it’s generally pretty easy to identify the sex of a cannabis plant, as females are adorned with pistillate flowers while males are hung with stamens that are often referred to as “bananas” because of their appearance.
Hermaphrodites are female plants that also contain one or more banana. These stamens can sometimes form inside the female flower itself, replacing the pistil, but will more often appear alongside the female inflorescences, occupying some of the plant’s nodes (where the branches meet the main stem).
A recent study found signs of hermaphroditism in five to ten percent of plants that were being grown indoors under commercial conditions[i]. While the frequency at which this occurs varies between strains, it’s clearly important to keep monitoring your plants throughout the flowering phase in order to spot any unwanted hermaphrodite inflorescences before they get a chance to self-pollinate.
The development of male stamens on a female flower, from emergence (a) to full maturity (f) over a period of three weeks. Image: Holmes et al. (2020)/Fronties in Plant Science
What’s the problem with hermaphroditism?
When growing cannabis it’s essential to prevent the females from being pollinated, which means your growing area needs to be a banana-free zone. This is because all of the cannabinoids are contained within the female flowers, which will grow to their maximum size if they don’t get fertilised. However, once pollinated, these plants will divert most of their energy to the production of seeds instead of resin, resulting in low-quality weed that is full of seeds but distinctly lacking in cannabinoids and terpenes.
To avoid any unwanted hanky-panky within the growing area, it’s become common practice to remove (and often destroy) the males, leaving the females to reach their full flowering potential. Yet this arrangement can be scuppered by an undetected hermaphrodite, which can easily fertilise an entire crop if it isn’t dealt with before its anthers open and release their pollen. So if you have meticulously eradicated all of your males but still end up with weed that is full of seeds, you know that one of your females must have developed into a hermaphrodite.
The production of pollen by a hermaphrodite inflorescence, from the development of anthers (a) to the release of pollen (d). Image: Holmes et al (2020)/Frontiers in Plant Science
How to prevent hermaphroditism?
While hermaphrodites may be a real nuisance, it’s worth remembering that all life on Earth has evolved with one purpose: to survive. In keeping with this universal drive to endure, cannabis hermaphroditism has developed as an adaptation to help the plant reproduce quickly when it feels threatened.
As such, it is always more likely to occur when the plant is under stress and thinks it needs to go to seed. This stress can be caused by any number of environmental factors, such as the overuse of pesticides and fertilisers, interruptions to the photoperiod, pruning during the flowering phase, too much or too little water, undesirable temperature or the presence of pests.
Eliminating this stress by providing the optimal growing conditions is therefore the best way to reduce the frequency of hermaphroditism in your crop. To do this, you’ll need to diligently monitor and control all of the above factors, while also making sure to harvest your flowers at the right time. If flowers become too mature without being fertilised then the plant may take matters into its own hands and start sprouting bananas so that it can self-pollinate. Knowing when to harvest can be an art in itself, and is typically determined by the colour of the trichomes, which turn from clear to milky to amber as they develop.
It’s also important to bear in mind that some strains will simply be more genetically prone to hermaphroditism than others, so it’s worth doing some research on this before buying seeds.
What to do with hermaphrodite plants
Given that the priority is to prevent pollination from occurring, you’ll always want to get rid of any male flowers. If a hermaphrodite plant has numerous bananas on it then it’s probably a good idea to just eliminate the whole plant, although in some cases it may be possible to just remove the male flowers using tweezers, if there are only one or two present. However, it’s important to be extremely careful when doing so, as the last thing you want is to accidentally spread some of the pollen.
Alternatively, if you notice male flowers starting to appear on female plants at the end of the flowering period then it could be a sign that its time to harvest, in which case you’ll want to start picking your bud without delay.
Of course, all of the above only applies if you are just trying to grow high-quality bud, and it’s a bit of a different story if you are actually attempting to breed plants. Obviously, male flowers are necessary for this purpose, so you won’t be eliminating these while breeding. It’s also here that hermaphrodite plants really come into their own, as the seeds produced from self-fertilised hermaphrodites always give rise to female offspring.
Commercial breeders therefore rely on hermaphrodites when creating feminised seeds, and often introduce chemicals like silver nitrate to deliberately stimulate the production of hermaphrodite inflorescences.
The rest of us, though, need to be on the lookout for any unwanted stamens on our plants, otherwise we could find our sinsemilla dreams are dashed by an undetected hermaphrodite.