whiteflies cannabis


White Flies / Whitefly

White flies look like tiny white moths when they’re flying around and otherwise behave a bit like spider mites; hanging out underneath the leaves and stealing essential nutrients from the plant. This results in white spots on the top side of the leaf, though most growers will notice the tiny white bugs (around 2 mm long) fluttering around before they notice any actual leaf damage. White flies are easily spotted with the naked eye. If you shake the plant a little, they’ll take off into the air.

An infestation can get out of control if you ignore it! The eggs they lay are practically glued to the plant, so you can’t wipe them off.

They look like tiny moths flying around your plants

Whitefly nymphs on the back of a leaf

Adult whiteflies & round young whiteflies (nymphs)

Proven White Fly Remedies

1.) Insecticidal soaps

Fatty acid salts or insecticidal soaps can be a good choice against whiteflies. They weaken the outer shell of aphids but are safe to use on your plants and they don’t leave much of a residue.

With soaps, coverage is very important as it does not stay on your plant for long, so follow-up applications may be necessary. Although this is considered safe, avoid getting any on your buds!

2.) ​Neem Oil

Neem Oil will leave an unpleasant taste/smell on buds when used to treat flowering plants, so again, don’t let this stuff get near your buds! There’s also some evidence Neem oil may be harmful to humans so use with care! That being said, Neem oil is an all-natural remedy that is very effective against many different types of bugs and mold. You will need a mister (also called a “One-Hand Pressure Sprayer”) to spray all the leaves evenly, since neem oil and water can separate easily.

3.) Spinosad

Spinosad Products (safe & organic) – Spinosad products are organic and completely harmless to pets, children, and plants. Spinosad products can be used directly to kill whiteflies on contact and should be sprayed liberally anywhere you see aphids and especially under the leaves. Although maybe not as strong against pests as some of the more harsh insecticides, it does work and it’s very safe for plants, animals and humans!

Spinosad is an organic insecticide made from the fermentation of a specific soil bacteria (actinomycete Saccharopolyspora spinosa) and kills whiteflies via ingestion or contact by effecting the insect’s nervous system. Spinosad can be a good choice for organic and outdoor growers, because it is very toxic to whtieflies, but is less toxic to many beneficial insects and spiders.

Note: Most spinosad products are effective for only about 24 hours after being mixed with water, so only mix as much as you will need per application. Anything left over will be waste.

You will need a mister (also called a “One-Hand Pressure Sprayer”) to cover all the leaves evenly when spraying them with spinosad products.

4.) Essentria IC3

Essentria IC3 Insecticide is a mix of various horticultural oils that is organic and safe for humans. It is often marketed as a “bed bug killer” but it can be effective against whiteflies when the plants are treated regularly. Unfortunately it only stays effective on the plant for about 8 hours so you will want to either apply this daily or combine with other options. You will need a mister (also called a “One-Hand Pressure Sprayer”) to spray all the leaves evenly.

Whiteflies almost look cute… until you see what they do to your plants!

Plant Symptoms

  • Bronze or brown patches
  • Brown or slimy roots
  • Brown or yellow leaf tips/edges
  • Buds dying
  • Buds look odd
  • Bugs are visible
  • Curling or clawing leaves
  • Dark leaves
  • Drooping plant
  • Holes in leaves
  • Mold or powder
  • Pink or purple on leaves
  • Red stems
  • Shiny or smooth leaves
  • Spots or markings
  • Twisted growth
  • Webbing
  • Wilting leaves
  • Yellow between leaf veins
  • Yellow leaves

This page is part of our Plant Doctor series. You can use our tool to filter by symptom and help diagnose your plant.

Learn how to identify and get rid of white flies and prevent this common indoor plants pest from ever attacking your cannabis again.

Most Common Pests In Cannabis: White Flies

White flies affect all plants, including cannabis. They hide on the underside of the leaves, where they reproduce and suck on the nutrients your plant has.

1. What Are White Flies?

White-flies are sap-sucking aphids that hide on the underside of the cannabis leaves. These white moth-looking bugs feed on the contents of your plant’s leaves, draining out its energy. Lucky for you, they can be easily controlled and eliminated with insecticidal soaps, yellow sticky and a good airflow.

These tiny white moths feed on the nutrients your plant holds and glue their eggs to your plant, making it difficult to remove them without damaging it.

They can reproduce super fast, being able to lay up to 300 eggs that will hatch in around 24hs.

Note: Even though they’re called flies, they’re not flies at all. White flies are related to sap-sucking aphids.

2. What Do White Flies Look Like?

These bugs looks like a tiny white moth, they can grow up to 2mm long, have wings, antennae and can easily be spotted flying around your plant if you shake it a little bit.

They usually have fluffy-looking legs and depending on where you live, they can have red eyes and a yellowish head.

3. Where Are They Found?

White flies can be found on any part of the plant, although they usually hide on the underside of the leaves, where they lay their eggs.

It can be fairly easy to spot them, because they will fly if you shake your plant.

So if you shake it and look closely, you will be able to see them, despite their small size.

4. What Do White Flies Do?

White flies feed on the nutrients your plant contains, just like spider mites , they bite the leaves and suck out their content.

They can lay up to 300 eggs, which can hatch in a day and completely mature in around four weeks, making it a pest that spreads fast.

The eggs will hatch and the new born white flies will start feeding on your plant, this is super dangerous because white flies can carry diseases that can gravely affect your plant.

5. White Flies Symptoms

You can find signs of white flies since the beginning, although the yellow spots they leave when feeding on your plant can be confused for other things, there is a way to be sure white flies are attacking your plants.

To spot them, you need to shake your plant, this will cause them to fly off and you will clearly see them.

Another way is to check the underside of fan leaves for eggs, you should be able to see small white eggs glued under your leaves.

Signs that a white flies infestation is getting serious is the yellowing and drying of the leaves.

At this stage, leaves will start to die and fall off, and you will start to see a reduced growth and overall development.

6. How To Prevent Them?

There’s not much you can do to prevent white flies, it is crucial to have a good air flow because this will cause them to not feel safe and look for another place to lay their eggs.

Other than that, you should check your plants thoroughly everyday.

You can also place yellow sticky traps all throughout your growing space, although this won’t exactly prevent them but you will see when they start to appear.

7. How To Deal With Them?

If you happen to get white flies you should spray your plant with organic insecticides and only move on to more aggressive insecticides if they’re not working.

You can deal with them with Neem Oil or insecticidal soaps.

Remember everything you spray on your plant can affect its growth, especially in the flowering stage, where it can affect the smell, flavor and effect your buds will have.

8. In conclusion

White flies won’t risk your harvest unless you let them be for a long time.

Even though they reproduce quite fast, it will take a lot of white flies to kill your plant.

Your plant will go through a process of slowly running out of nutrients, yellow and the leaves falling off before it starts dying, so you have a fair amount of time to deal with them.

As always, remember the best way to avoid having any problems is growing in a good environment and checking for any kind of bugs everyday.

White flies affect all plants, including cannabis. They hide on the underside of the leaves, where they reproduce and suck on the nutrients your plant has. 1.