How to determine the sex of a cannabis plant

 

The gender of a cannabis plant determines multiple factors including its potency and flavor. Female plants are great for medical and recreational use while male plants are used to cultivate the plant to produce better plants via selective breeding. Marijuana has many applications including industrial ones. For example, hemp is a kind of cannabis grown to produce ropes, fabrics, and biopolymers including biofuel and resins. Hemp is used to produce industrial goods, usually, after female plants are pollinated.

However, we are not using hemp, are we? Our main goal is to grow THC and CBD rich strains of cannabis at home for personal or commercial use. Since Californian law allows us to do it, we better learn how to do it well! Learning how to distinguish male from female cannabis is one of skills that will help you harvest a great batch of exceptionally flavorful cannabis!

Why do you need to know about it?

Many cannabis enthusiasts would like how to sex cannabis plants as it helps to grow plants with higher concentrations of THC. Pollinated female plants do not produce THC and accumulate CBD instead which is not good if you are planning to use marijuana for recreational purposes. Comparing male vs female cannabis is quite simple for a marijuana hobbyist.

Female cannabis:

Contains higher amounts of THC, CBD, and CBN.
Can be used for breeding and medical purposes.

Male cannabis:

Contains less THC, CBD, and other cannabinoids.
Used predominantly for breeding purposes.

One of the problems that many breeders and hobbyists encounter is that male plants can pollinate female plants making them less useful to people who want to grow a nice bulk of buds and use them for recreational or medical purposes. It is highly important to remove male plants from the plantation as soon as possible.

Accidental pollination of the whole plantation and subsequent reduction in the quality of the final product are main reasons why you need to know how to identify a marijuana plant. Another important detail that you need to know is that the science behind gender identification of cannabis is still uncertain. We still don’t know for sure how individual plants acquire a specific gender before germination. There is also a chance that a female plant will turn hermaphrodite.

More about hermaphrodite cannabis

It is a fear of any cannabis enthusiast with a greenhouse in their backyards is that female plants turn hermaphrodite and start pollinating the whole plantation. It does not happen often but regularly enough to force all cannabis breeders and gardeners to always be on guard. The difference between hermaphrodite and female plants is apparent since it produces both female and male flowers. Hermaphrodite plants stand out immediately.

Male weed plants also can turn hermaphrodite. Some people even devised techniques to turn male plants to female/hermies via ethylene infusions (female hormone). However, having a hermie in your greenhouse is undesired if you are not planning to do any breeding. You can also purchase only female seeds to try cultivating your own weed or start caring about a pot plant.

What causes cannabis plant turn hermaphrodite? Female and male plants require a very specific environment to strive. When environmental stress is too much, plants start developing traits of both genders. There are various factors that may affect the gender of any given plant:

Temperature. Higher temperatures (above 85F) may cause the transition. Inappropriate lighting devices can heat the environment to such temperatures.
Excess light (over 40000 lumens per square meter) as well as excess red light also stress out plants.
You also should pay attention to watering. Low humidity and insufficient water supply put additional stress on cannabis plants.

Methods such as ethylene infusion can revert the process in some cases. However, it is recommended to remove plants with both male and female preflowers in order to ensure that your plantation is safe from accidental pollination.

How to sex marijuana plants

Examining preflowers is one of the things that you should be doing on a regular basis. If you purchased seeds from a trusted provider, you don’t necessarily need to check the plants as early as 1-3 weeks after planting. However, it may be necessary in cases when you want to protect your plantation from male plants when you are not sure whether seeds are female.

Determining the gender with special chemical tests is an option that any hobbyist should consider if they do not have enough experience. Such tests can be purchased from manufacturers like Phylos. Many tests allow you to identify the gender of any given plant when they are 7-days old. The method is based on DNA-testing and allows you to significantly reduce the likeliness of male plants appearing in your greenhouse unexpectedly.

Such testing is not necessary if you can check the plants regularly. You will notice that preflowers start forming on plants as early as 3-4 weeks after planting. Early preflowers mean that you are observing a male plant since female plants start developing those only when they are 4-6 weeks old. When preflowers form, you can reliably identify the gender of a plant.

Let’s take a closer look at a cannabis preflower to learn how you can distinguish male plants from female ones.

Female weed plants

Female preflowers look slimmer and usually grow from the stem. The bottom of the flower is thin and does not have a ball shape or the ball shape is barely visible. These preflowers are very small and start appearing when the plant is about 4-6 weeks old. Inspecting the plants with magnifying glass or your phone camera is a good way to find early buds on the stem. As mentioned above, male preflowers start appearing much earlier.

The picture shows that preflowers are very thin and narrow without a small ball underneath. The buds do not appear early and will be barely palpable before they pop up.

Male weed plants

Male preflowers have a bulkier form and usually grow out of big fleshy bulbs. These preflowersstart appearing very early (3-4 weeks). Hermies also start growing male flowers and you will notice them when the transition happens. It may occur at nearly any age hence you need to check the greenhouse regularly and closely inspect individual sprout to identify male weed plants as early as possible.

The picture shows that male preflowers are bulky with a bigger ball underneath. These spherical buds will start appearing early and often protrude on the stems before they start taking shape.

Hermaphrodite weed plants

Hermies have both kinds of preflowers on their stems. Male buds appear sporadically, often near female preflowers. The process can be reverted, as stated before, but it is an unproven technique and may not work out as well as one could expect. It is recommended to remove hermaphrodite sprouts in order to avoid pollination.

Checking the plantation

In order to ensure that plants in the greenhouse on pot plants do not develop pollination sacks, you will need to inspect the garden as regularly as possible. Start inspecting daily after 1-3 weeks and closely look at stems to find stipules. They are extremely small and may not have any distinct traits early on. However, you will be able to notice a characteristic change in the appearance of stems as soon as buds start appearing.

Early preflowers are often palpable before they can be seen. If you stroke the stem with your thumb, you may feel a small bump in places where preflowers are supposed to grow. It means that preflowers will start forming very soon. The process is gradual and young sprouts do not present any danger to your plantation. However, they will start producing pollen when the plant matures.

Daily inspections are a great way of sexing marijuana as early as possible. As mentioned previously, use a magnifying glass or a phone camera to see the buds. Early identifiable buds can be as small as 2-3 millimeters in size. Nonetheless, you can already tell whether these preflowersare male or female. You can take a photo with your phone and inspect photos later on by comparing them to reference images featured in the article above.

If you are not sure in your gardening abilities, by all means order a special chemical test. These tests can be helpful even when plants are about 6 weeks old. Use them to reliable determine the gender of any given plant if you have any doubts. Losing a whole plant due to misgendering is quite a bad feeling!

Optimal conditions

It is important to keep the conditions as close to optimal as possible. Marijuana is not an overly sensitive plant and strives in many environments. However, various factors significantly affect the concentrations of cannabinoids and even the gender of a plant. Both male and female plants will grow better in suitable conditions.

It recommended to keep the temperature within the 60-68F range which results in relatively high humidity. You can spray water to reach the concentration of water in the air quicker. The air will be able to hold a lot of water, more than enough to keep the plants sufficiently nourished. It is important to provide enough water to the plants during the root development. The strength of roots dramatically affects how much water and nutrients a plant can utilize over the course of its life.

Proper ventilation in your grow room will prevent artificial lamps from heating the room too much meaning that temperature control will depend on both heating and ventilation.

Many experienced breeders recommend keeping the relative humidity close to 70% in a room where you grow cuttings. Here, you will need to keep the temperature at about 71F and ensure that humidity is high enough to provide plants with water despite their relatively weak root systems. Many recommend gradually reducing the humidity as the plant matures. Plants age 1-3 weeks require 70% relative humidity while plants age 7-9 weeks in their flowering phase will need 40% relative humidity.

Maintaining optimal conditions is the only way to ensure that the plants won’t develop male flowers during early stages of growth.

It is very important to regularly check the conditions with thermometers and hygrometers that you can purchase for a couple of bucks. Hygrometers are usually placed above the plants in the middle of the room. Outdoor gardening is harder. It requires you to regularly inspect the plants over the course of the preflowering stage to identify male buds early. You won’t be able to control the environment and the growing process takes slightly more time due to the lack of artificial 24/7 lighting. Humidity in drier regions is also a problem often enhanced by winds that may erode the soil even in a pot that you leave on the balcony.

Ordering seeds and equipment

Whether you want to start breeding your own strains of cannabis or prefer homemade marijuana, you will need to get high-quality seeds from a trusted supplier. You cannot identify the gender of seeds on you own so purchasing seeds from people who know how to produce female seeds is critical to the success of your endeavors.

Knowing the difference between male and female cannabis is extremely important for people who want to grow marijuana at home for personal use. Pollinated and male cannabis plants do not produce enough THC and CBD to make you high or provide a strong healing effect. The lack of cannabinoids will also render these plants useless for oil making. You won’t be able to infuse any oil with cannabinoids and enjoy remedies based on medical marijuana.

When it comes to recreational and medical use, growing male weed plants is a complete waste of time. To ensure that your crop is of high-quality, we recommend you to purchase all the necessary equipment including chemical tests, hygrometers, thermometers, and a good magnifying glass in addition to pots, lighting, heating, and watering equipment that you will require to set up a nice greenhouse or an indoor grow room.

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