Herming can be a total nightmare for cannabis cultivators. Marijuana typically comes in male or female versions. However, a female plant may sometimes show fully developed male structures that pollinate female buds and other plants. Cannabis cultivators call these sexually confused plants hermies or hermaphroditic.
Sadly, hermies can destroy your harvest—so you must spot them early. However, it’s not all bad news: some hermaphroditism is genetic; you can’t avoid it. On the other hand, stress may lead to plants becoming hermies too, so you may need to change your growing environment. In this article, we’ll detail why plants start herming and how to prevent it:
The Main Causes for Cannabis Plants Herming
1. Leaving Marijuana Plants in the Bloom Phase
If you leave your cannabis plants in the bloom stage for too long, you may begin to witness hermie clusters. If you have strong resin glands and your plants are in the last two weeks of the bloom stage, you should test a bud to see how potent it is. Moreover, you should consider harvesting those plants before the seeds have time to develop.
It only takes around 2 to 3 weeks for seeds to mature. If you witness some hermie features before harvest time, let those plants grow in an isolated tent so their pollen won’t pollinate the other plants.
2. Your Lighting Is Excessive
If you’re using LED lights to grow cannabis, you can easily overdose on light radiation without knowing if you’ve burnt the leaves. However, using a professional light meter can help. You should maintain PPDF readings of around 500-700 during the bloom phase without additional CO2. If you use more light than that, you may stress the plants.
You can also trigger hermie flowering by placing your plants too close to the lights, thus creating excess bud heat. However, you can avoid burning your plants by using a thermometer. Keep your temperature below 87 Fahrenheit, and you should be fine. It’s even better if you keep the leaf surface temperature below 78 Fahrenheit.
3. Your Plant’s Genetics
Some cannabis strains—such as Sativa dominant or pure—may naturally develop hermie flowers. That’s because hermaphroditism is sometimes a female marijuana plant’s attempt to supply pollen to itself when the male plants aren’t supplying them.
In addition, breeders sometimes cause hermie traits when trying to create autoflowering seeds and feminized seeds.
4. Irregular Light Cycles
Having regular light cycles is incredibly important when growing cannabis. You should ensure you have zero light leaks. Even small amounts of light—such as a tiny glow from an active power strip—can cause hermie flowers.
However, light issues typically aren’t a problem with autoflowering plants, which don’t require a specific dark period and flower on their own.
5. Environmental Stress
Many environmental problems can cause hermies. These include raised room temperatures, relative humidity, and vapor pressure deficit. If pests, gray mold, and powdery mildew attack cannabis plants, the stress can create hermie flowers.
6. Root Zone Stress
Causing stress to the root zones is one of the best creators of hermie flowers. You can stress your root zones by underfeeding, over-fertilizing, using incorrect root zone PH, the wrong nutrients, and inferior root zone substrate management.
How To Stop Your Cannabis Plants From Herming
1. Use High-Quality Clones and Seeds
One of the best ways to avoid hermie flowers is by purchasing the best cannabis seeds from reputable breeders. Before you buy any cannabis seeds, conduct research on the breeder and read previous reviews. You may spot reports of hermaphroditism.
In addition, be careful with the seeds you choose. Sativa strains, landrace strains, and feminized photoperiod strains develop hermie flowers more often than hybrid strains, Indica/Kush strains, and non-feminized strains. Autoflowering strains rarely develop hermie flowers either.
2. Perfect Your Growing Environment
Regardless of your cultivation experience, perfecting your growing conditions is rarely straightforward. Still, you should strive for perfection; it will reduce the likelihood of sprouting annoying hermie flowers.
For example, ensure you monitor the lighting, feeding, watering, CO2, air movement, and climate control daily. Remember, giving your plants too much heat, light, CO2, and nutrients can create stress and make your flowers go hermie.
3. Remove All Pests
Pests are your worst nightmare when growing cannabis, and you must ensure you monitor the number of pests near your flowers. Common pests include broad mites, caterpillars, russet mites, stink bugs, whiteflies, grasshoppers, and crickets.
However, it’s possible to reduce the number of pests in your harvest with some simple techniques. Using caterpillar spray, for example, can be a lifesaver on your cannabis farm.
4. Monitor All Your Flowers Closely
Closely examining all your flowers at the start of the bloom phase is critical. You should use a jeweler or magnifying glass to observe your plants. Not only are you looking for male floral clusters, but you should also look for pistols turning from white to red. That’s a sign that pollen has fertilized your buds.
If you don’t have male cannabis plants nearby, you know what’s caused the redness: hermie flowers.
Let’s be honest: hermie flowers are a pain in the neck. Unfortunately, they are hard to track and maintain—especially if you’re new to growing cannabis. If you notice hermie flowers in your harvest, you should remove them. That way, you’ll minimize the risk of spreading pollen sacs around your harvest.
If you follow the tips in this article, you’ll reduce the number of hermie flowers in your harvest and create the best possible cannabis.