One day you might walk into your grow room and suddenly notice male flowers growing on your female plants. This might seem strange at first, but it is in fact, quite common. This article describes hermaphrodite cannabis plants and what you can do to prevent them.
Unless you are trying to breed cannabis to produce seeds, male flowers are not favourable. Most growers have the intention to grow purely female plants, which only produce bud. A hermaphrodite plant still develops flowers, but if the male bud pollinates the female bud then the final result will have seeds in it. Seeds are not tasty, however you may not mind having a few in your harvest (free plants, right?).
Male and Female Cannabis Flowers
In order to properly diagnose a hermaphrodite plant we need to understand the differences between a male and female cannabis flower.
If you obtain regular seeds, there is more or less a 50/50 chance that you will end up with males or females. Because of this randomness, there is a higher possibility of a hermaphrodite plant.
Feminized seeds have around a 99.9% chance of being female. Most growers choose feminized seeds because the priority is to produce only bud. After all, that is what most of the market is demanding. Depending on where you buy your seeds, most feminized seeds will be genetically stable. However, you must still keep a close eye just in case a hermaphrodite does suddenly appear.
A male flower looks like a small, green ball or sac. They actually resemble the shape of a seed, which has a slightly pointed tip on one end, and is rounded on the other end. The male flower will not pollinate the female flower until the sac has opened.
A female cannabis flower can be described as a small tear-drop shaped bud with one or two white 'hairs' emerging from its pointy tip. The bud is what is known as the calyx and the hairs coming out of it are called stigma. These two parts form what we refer to as a pistil.
What is a Hermaphrodite?
Put simply, a cannabis hermaphrodite is a plant that produces both male and female reproductive organs. Also known as a 'hermie', a hermaphrodite can occur naturally or develop because of plant problems.
There are two different types of hermaphrodite which can appear in cannabis plants. The first is a true hermaphrodite, and happens when both male and female flowers grow separately on the plant. A grower has little control over this type of instability because it is more to do with the strain's genetics. Even if the conditions are spot on, a true hermaphrodite will show its colours eventually.
Hermaphroditism that occurs during full flowering can be the result of stress. Mixed-gender cannabis plants actually develop a new reproductive organ called a 'banana'. The banana (or 'nanner') is an extension of the male gene that grows out of a female flower. It does this as a final attempt to survive by sexing itself.
A hermaphrodite banana flower looks like a long, yellow finger that as you may have guessed, resembles a banana. A banana spreads pollen from the moment it emerges, meaning it is likely there will be some seeds already growing within the female flowers.
| Organ |
Male |
Female |
True Hermie |
Mixed-Gender |
| Pollen Sacs |
X |
|
|
|
| Calyx With Pistil Hair |
|
X |
|
|
| Pollen Sacs + Calyx With Pistil Hair |
|
|
X |
|
| Bananas (Flowering) |
|
|
|
X |
The Causes of Hermaphrodite Cannabis
The main cause of hermaphrodites is stress. There are many factors which can stress out a cannabis plant, but most of it comes down to choosing the right strains and maintaining a stable environment.
- Light Leaks - Unless you are growing autoflowers, it is extremely important to keep the night time as dark as possible. Even a small light leak has the ability to confuse a cannabis plant.
- Temperature - Cold conditions can be responsible for turning a cannabis plant hermaphrodite. Sudden drops in temperature or overly cold nights can be enough to shock a plant.
- Drought - A lack of water is a big stress for a cannabis plant and quickly affects growth when left unattended. Dried out roots can be a signal for a plant to produce bananas because it 'thinks' it is dying.
- Deficiencies - Without the proper nutrition a cannabis plant cannot function properly, causing it to try and end it's cycle early. Buds mature before they have fully developed and may produce bananas.
- Unstable Genetics - This one is often overlooked, however choosing a breeder with a reputable history of producing seeds is one of the best ways to be sure you won't end up with a hermie.
Early signs of flowers (preflowers) can be noticed growing around the leaf nodes on branches. True hermaphrodite flowers can appear during the vegetative stage but they are very hard to catch because they are so small. Normally, the signs become visible during the pre-flowering stage, just before female flowers start growing in numbers.
What To Do With A Hermaphrodite
If you discover a hermaphrodite in your cannabis garden, it is recommended that you remove it from the grow space immediately. Pollen can spread very quickly once male flowers bloom, so unless you're trying to produce seeds, separate it from your females as soon as possible.
A hermaphrodite plant can still produce bud, and although it will have seeds in it, it is better than nothing. If you have the space and you're willing to look after the plant until the end of its cycle, then it's worth keeping. There are plenty of ways hermaphrodites can be processed. For example you could make hash, edibles or other extracts.
It is possible to slow the development of the male gene in a hermaphrodite. If the conditions are corrected and male flowers are removed early enough, you can help to prevent the problem becoming too serious. Be aware that trying to save a hermaphrodite can result in low yields of buds that have seeds in them. By keeping it, you risk other plants getting pollinated.
The point of removing male flowers is to try and prevent the male gene becoming too dominant. If you do decide to keep and control a hermaphrodite, be sure to check it daily and do not keep it in the same room as your females. Most growers scrap their hermaphrodites, but it is up to you.
Note: Wear gloves when handling hermaphrodite plants and change your clothes afterwards before going back into your unpollinated space.
How To Avoid Hermaphrodites
Your heart may sink if you suddenly discover male flowers in your cannabis crop. This is why it is important to start checking your plants early on during flowering, because it becomes much harder to spot them once buds have developed.
Tips for avoiding hermaphrodites:
- Look for male flowers at the end of the vegetative period and early blooming as preflowers develop.
- Keep stable grow room conditions.
- Take good care of the roots.
- Choose reliable strains that can handle stress.
It is important to note that seeds taken from a hermaphrodite plant are more likely to produce hermaphrodite plants. Even if the original plant was grown from a feminized seed, the genetic makeup is destabilized when hermaphroditism takes over. Make sure you know your source.
Basically anything that stresses your plants can cause them to turn hermaphrodite, so carefully monitor your environment and remember to inspect the preflowers as they appear. Regularly check your pH, replenish nutrients, and monitor temperatures and humidity.
Black Jack Bagseed (Hermie) by herewegrow from GrowDiaries
Conclusion
The first thing to do if you discover a hermie in your garden is to stay calm. Do not fret. A hermaphrodite is not the be all and end all of your hard work. Keep an eye on your ladies and you should be able to catch a hermaphrodite before its flowers manage to spread any pollen.
If you've got any tips on the topic of hermaphrodites, why not discuss them with fellow growers down in the comments section? We would love to hear from you.
External References
Hermaphroditism in Marijuana (Cannabis sativa L.) Inflorescences – Impact on Floral Morphology, Seed Formation, Progeny Sex Ratios, and Genetic Variation. Frontiers in Plant Science. - Punja, Zamir & Holmes, Janesse. (2020).
This article was updated September 2020
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