Pest ControlPests and Problems

How To Get Rid Of Whiteflies On Marijuana

How To Get Rid Of White flies On Marijuana

Probably all or most marijuana growers have at some time or another an infestation of whitefly, those tiny whitish mosquitoes that  can leave our plants sick or even worse destroy them completely. In indoor crops can be very susceptible and infestations can quickly reach critical numbers due to the perfect conditions and no natural preditors

Treating our plants to eliminate this pest is essential if we are to get good results at the end of the harvest, but as always the best way to avoid it is to prevent it. Below we will explain everything about this bug, since knowing the enemy will make it easier to dispose of it more easily. Likewise we give the best solutions and methodologies for use.

How To Get Rid Of Whiteflies On MarijuanaWhat are whitefly?

It is a flying insect that lives and reproduces in warm climates where the temperature is above 15 degrees Celsius and 35 degrees Celsius Temperatures below or above these parameters and the whitefly cannot survive. There are dozens of varieties of white fly but the most common in cultivation of marijuana is the species Trialeurodes vaporiorum. Its size is very small, between one and two millimetres. Its colour is whitish or yellowish.

Indoor grow rooms where the temperature is usually optimal for these insects means they can multiply their population x 200 every month. Since the females lay an average of between 180 and 200 eggs, which means it can quickly become an overly abundant and damaging pest for our plants.

Eggs are laid on the undersides of the leaves of the marijuana plant and is where they mature until hatching. The egg size is really small, just 0.25 millimeters, so unless you have a widespread population … it can be difficult to see these eggs without the help of a lens or microscope.

What are whitefly?

How whitefly affects your Marijuana plant?

This type of insect is very harmful to our plants as it feeds on plant sap. Having a couple of white flies is not a problem, but it is likely that once you have seen the eggs a couple will soon turn into hundreds.

Imagine thousands of insects sucking sap from a cannabis plant, the plant’s future if the pest is not removed is very likely death.  If the plant does not die, production of buds and their quality will be much lower. If the plant is in veg it will be seriously affected, losing vigour and even stopping growth entirely.

Furthermore, these insects can transmit different kinds of viruses to our plants, which weakened by the removal of sap by the whitefly …. will be very badly affected.

How whitefly affects your Marijuana plant?

How to detect whitefly on Marijuana plants?

How to tell if we have whitefly in our grow or not, it’s really simple. Whiteflies feed on the sap of our plants and when this happens, small circles occur in the leaves of a lighter colour. It is very easy to see that we have some kind of insect on our plant.

When we see that leaves our plant have this kind of discolouration or pitting, we must look on the underside (bottom) of the leaves to find the source. If we see these small flies or their eggs … we know for sure that it is a plague of whiteflies.

If the pest is already widespread in our grow,  shake a little leaf and see dozens of small white or yellowish flies fly out. Luckily they are easy to identify, without using microscopes or lenses.

How to detect whitefly on Marijuana plants?

Preventing whitefly in crops of marijuana

The best medicine for all diseases and pests is always prevention. Insects such as those most often interested in our cannabis plants are also susceptible to certain plants in nature, some of which the odour is repelling or are  toxic to these insects.

Neem oil is one of the best repellents can use, is completely natural (100% BIO) and is economical. It is enough to spray our plants with water and a little diluted neem oil in it every fifteen or twenty days to keep whitefly and many other insects away from our crops.

In indoor growing we can also make a filter in the air inlet of our grow room, thus preventing the entry of insects. For instance stockings can make a excellent filter, letting the air pass whilst preventing certain insects sneaking through

Preventing whitefly in crops of marijuana

Eliminating whitefly infestation on my cannabis plants

If we already have a infestation on our plants, we must act immediately. Since they reproduce exponentially and in just one month could multiply its population by two hundred. We have two options we can use, remove the whitefly with natural products (biological) or chemicals.

If we are in flowering stage chemicals should no longer be considered an option, as they may damage the buds or leave traces of toxins in them.

Eliminating whitefly infestation on my cannabis plants

Remove the whitefly with natural options:

Mix potassium soap (or soap) in a bucket of water and add neem oil. With the help of a sponge we can wash all the leaves individually on our plant, being careful not to break the stem, wipe both the top and the bottom of the leaf. Repeat this every 10 days.

Use an yellow adhesive anti-mosquito trap near our marijuana plants which are infected by whitefly. The whitefly are attracted to this colour and remain stuck in the trap.

Use a natural pyrethrin-based insecticide (chrysanthemum extract) and spray our plant every 10 days.

Chemical options to kill whitefly:

We must NEVER use chemicals if our plant is in the process of flowering, because toxins could stay in the buds that later we smoke or eat. Go to a nursery or grow shop to buy the chemicals which can be used on food crops.  NEVER use chemical solutions in our plant if in Flower. Spray our plant with products purchased and follow the instructions dont be tempted to mix a concentrated solution as this could kill your plants as well as the pests! use in conjunction with the yellow anti-mosquito traps we mentioned earlier.Chemical options to kill whitefly

If you have any questions or suggestions, you can leave a comment and we will help you solve it.


Cannabis Sativa, Cannabis Indica, and Cannabis Ruderalis: Thank you for being the “Gateway drug” to perpetual inspiration, compassion, benevolence, and medicinal miracles: Cannabis grower, photographer with a long experience in cannabis cultivation. His articles are journalistic reports of places where cannabis is already legally cultivated and owned. They are intended to give an impression of the wide range of cannabis cultivation. These reports are intended to help identify the truth about cannabis and reduce prejudice.


  1. They thrive on CO2 when the ppm is in the 1200-1500 range, I would have thought 100% CO2 would kill your plants pretty quickly high doses would internally affect the PH of your plant (making it acidic)

    I wouldn’t recommend it but if in the interest of science you want to try it and report back I for one would be interested ; )


  2. Since plants thrive on CO2, would a 100% CO2 environment really hurt the plants? I may have to regulate the inside temperature (keep in shade, water down can maybe). I may also have to leave a small opening with the lid for gases to escape (and maybe a few lucky white flies).

  3. Hello Quete
    I think you might suffocate the plants instead!. Seriously you would be better spraying the plants just before the dark period with a dilute soap solution or neem spray. Both are very effective at killing whitefly.

    good luck


  4. I have small, 2-3 foot plants and am considering placing the flowering plants inside a lidded trash can with a CO2 generator and hopefully suffocate the bugs within the 6 hour dark period.
    Any comments on this idea?

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