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Cannabis Aphids: How To Get Rid of Them

November 15, 2021

Aphids are a widespread pest that affects cannabis farmers in many countries. On this page, you’ll learn all about cannabis aphids, including what they are, how to identify them, and how to keep your plants free of aphids.

There are many kinds of aphids, but the one that affects cannabis plants is called “plant lice.” These tiny insects come in colors ranging from gray to green and pink. It’s difficult to see cannabis aphids with the naked eye, making them very hard to eradicate.

Aphids nurse on a plant’s sap, and their saliva can be toxic, which is why cannabis plants infested with aphids have discoloration and curling leaves. 

If not dealt with quickly, aphids will suck plants dry. A single aphid on weed can reproduce asexually very quickly and create a whole new colony in a matter of weeks. 

Read on to stop these pests from interrupting your cannabis plant’s growth. 

Cannabis aphid

What are aphids?

Aphids are tiny insects known for sucking the sap out of plants. They are between one and three millimeters in size and can vary in color. There are different kinds of aphids, such as the blackfly, greenfly, and of course, the infamous cannabis aphids. 

Cannabis aphids also have a variety of colors in which they like to present themselves, although generally, they are a light shade. 

Their colors can range from a pale yellow to a creamy color during the early season. As time progresses and the season gets late, you will see darker shades of aphids appear. Around this time, they can manifest many colors, from light green to light brown.

There are winged and wingless cannabis aphids, as well as spotted and unspotted. One thing is for sure though, they all possess the same traits and will cause equal amounts of damage to your marijuana plant if not dealt with ASAP. 

Where do aphids live?

You can normally find these critters roaming around the bottom parts of cannabis leaves. Aphids on weed try their best to hide, so be sure to check your precious marijuana plants regularly for these unwanted guests. 

Otherwise, they may also appear on your plant stem. Always check everything carefully, because as mentioned, they tend to play chameleon from time to time. 

Aphid life cycle

During early spring, a cannabis aphids’ life starts as a miniature egg, which has overwintered and then had an incubation period of around a week. Once hatched, they are known as nymphs. As nymphs, they will do a lot of growing and even molt.

Cannabis aphids will shed their exoskeleton between 3-4 times before reaching their adult stage. The overall nymph stage takes 1-2 weeks. 

Once they are adults, if they can last that long, they can live up to the ripe age of one month.

The above process is only the sexual reproduction aphid life cycle, which includes the males born in the late summer or autumn. We will discuss the asexual cycle under the next heading. 

Aphid reproduction

From late spring to early summer, female aphids will normally reproduce asexually, giving birth to live offspring. Aphids’ young are genetically identical females, and they can birth up to 5 per day. 

In the late summer stages, males will provoke a mating ritual, which results in sexual aphid reproduction. After they mate, the females will lay eggs on leaves or stems

The eggs will overwinter and hatch during the early stages of spring, and so the next generation of cannabis aphids colonize on nearby plants. 

Where do aphids lay eggs?

As briefly mentioned above, female aphids will normally lay their eggs on the cannabis leaves or stems. They can either be glued on directly or attached by a thread. 

Their eggs may appear translucent to avoid any predators seeking eggs benedict for breakfast. Another way aphids might ward off predators is by covering the eggs in a wax-like substance. 

Cannabis aphids
Cannabis aphids

What do aphids do to cannabis plants?

Cannabis aphids, also known as black flies or plant lice, are a serious problem for cannabis farmers since they drain the vitality from your plants

Cannabis aphids are an annoyance for marijuana growers because they sap the plant juices from the plant tissue. It is bad for your plant’s health and your wallet as aphid excrement attracts ants that herd them away from predators. 

Honeydew is the name given to the concentrated sugar solution that’s excreted by aphids. It can also cause sooty fungus on leaf parts.

Aphids on cannabis usually start near the top of a plant and work their way down, especially towards the bottom branches. You will see your leaves getting infested with greenish-brown aphids that suck on the plant’s juices and excrete a sticky honeydew simultaneously. 

How to identify a cannabis aphids infestation?

Do you want to know how to identify a cannabis aphids infestation? Aphids can usually be seen on the leaves and stems of cannabis plants. 

Green varieties may be harder to spot. They especially like hiding on the underside of leaves, away from direct sight. 

Look for little green or white dots, anywhere from one or two up into the hundreds per plant. Often, aphids on weed will show up in clusters at first before spreading out across your crop, getting ready for their feast. What causes an aphid infestation?

If winged “colonizer” aphids land on your plant and lay eggs, your plant will likely be infested. Cannabis aphids quickly lay eggs when landing on your leaves. 

Because of their high reproduction rate, a few colonizers may quickly result in hundreds or even thousands of aphids on a plant in just a couple of weeks.

How to get rid of aphids on cannabis plants

Here we will discuss the various methods you can use to get rid of those pesky cannabis aphids. Read on!

How to kill aphids on marijuana

As mentioned, cannabis aphids can be quite a pain if they find their way to your plant. The best way to kill the infestation is by simply taking preventative precautions

A good way to kill these colonizers is by getting hold of some beneficial predators. They will gladly feast on any pests that may be unlucky enough to land on your plant. These include ladybugs, damsel bugs, and many more.

In the below sections, we will further discuss the different methods to kill aphids on marijuana. 

Adding insecticide to weed plant
Adding insecticide to weed plant

How to get rid of aphids in grow room

Grow rooms are a great way to prevent most pests overall, but that doesn’t mean they won’t find their way in. 

Here are a few great ways to get rid of cannabis aphids in a grow room:

  • Keep the room closed as much as possible.
  • Get a couple of sticky traps to hang at the entrance of your grow room. They could catch some of the colonizers. 
  • Always have good airflow in the room. Many different fans will help with this, making the room undesirable and blowing away any winged aphids trying to enter the room. 

How to get rid of aphids during flowering

If you see big colonies of greenfly or blackfly sucking sap from your cannabis plants leaves during the flowering stage, here’s what you do

  1. Remove buds affected by cannabis aphids. 
  1. Put cannabis plants in a separate room (or bag) and allow them to dry out for one or two days. Aphids will fall off your plant when it’s dry!
  1. Wash cannabis plant leaves with water, which you need to clean afterward so that no aphid eggs remain on the cannabis plant.
  1. Spray cannabis leaves with neem oil or regular insecticide soap, which will kill cannabis aphids and their eggs.
  1. Repeat the steps every other day until all cannabis aphid infestation is gone. Using a small fan can help speed up the cannabis drying process by creating air circulation around cannabis plants affected by cannabis aphids.

Natural ways to get rid of aphids on cannabis

As mentioned, try aphid predators. There are several biological controls available for cannabis growers who want to control cannabis pests without using pesticides. Ladybugs and lacewings feed on cannabis aphids but may not be effective if infestations are moderate or severe. 

Aphids can reproduce rapidly—the best way to get rid of cannabis aphids is to destroy their eggs before they hatch. Good ideas include:

  • Introducing parasitic wasps and fungi can reduce aphid numbers, but this may take a few weeks to become effective.
  • Use insecticidal soap sprays to kill aphids on cannabis plants but not pose any risk to people or pets.
  • Use a strong stream of water directed at the cannabis plants to knock aphids off, and reduce plant stress by watering cannabis properly.
  • Turn off any nearby street lights if they attract flying insects, as this will reduce the number of cannabis pests that come into your grow room.
  • You can reduce aphid infestations by planting cannabis plants more widely apart. Leave around 12 inches between plants if cannabis aphids pose a threat.
  • Don’t let cannabis leaves sit on the ground, as this will create humid conditions that encourage pests and diseases.

Using chemical pesticides to get rid of aphids on cannabis plants

In short, it is not recommended to use chemical pesticides on cannabis plants

Pesticides that you may use to kill aphids on marijuana plants are available, but you run the risk of affecting the buds once flowering starts. If you want to give it a whirl, only use them during very early vegetative stages, so they are long gone by the time flowering starts. 

Any chemical residue left during flowering might make those who consume the buds very ill. 

How to prevent aphids on weed?

Aphid prevention is the best way to go when cultivating your glorious cannabis seeds. 

A good method for getting rid of cannabis aphids is to avoid them altogether. Aphid prevention stops infestations and allows you to grow healthy plants without any worries about pests or diseases. It also saves time and money in the long run! 

Here are some tips on how you can prevent aphids from attacking your precious weed:  

  • Use beneficial predators such as ladybugs, lacewing larvae, syrphid flies, damsel bugs, and spiders. These will eat all those nasty little cannabis aphids that are ruining your crop! 
  • Choose resistant strains of weed that have a natural resistance to cannabis pests
  • Make sure there are no other plants near your grow area. Aphids are notorious for being easily transportable pests that come from all sorts of places.
  • Use yellow sticky traps around the grow room to catch flying overwintering insects such as fungus gnats, winged cannabis aphids, and black flies. 
Ladybug eating aphids
Ladybug eating aphids

What should you do with the buds after stopping aphids?

Once you have terminated the threat, your beautiful buds will continue to grow as usual. Extra precautions are necessary when harvest time rolls around. It is highly recommended to cleanse your nugs of any cannabis aphids’ feces, shed exoskeletons, urine, and eggs

A good way to start this is by preparing three cleaning buckets:

  1. Add warm water (not boiling) to the bucket, along with two tablespoons of baking soda and lemon juice per liter. 
  2. Warm water (not boiling) with nothing added.
  3. Clean cold water. 

Follow these steps to clean your nugs of any cannabis aphid residue easily and safely:

  1. Submerge your cannabis bud in the first bucket.
  2. Gently shake it underwater for 20-30 seconds.
  3. Remove it from the bucket.
  4. Carefully shake off any excess water.
  5. Repeat these steps for buckets 2 and 3 in that order. 

It is important not to shake your nugs too hard. Otherwise, you might remove some of those rich trichomes your weed plant has worked so hard to grow. 


You have the questions; we have the answers. Here are some FAQs about aphids on weed that could help you on your growing journey. 

Can aphids kill cannabis?

The short answer is yes, they can kill your plant. Cannabis aphids suck on the plant’s sap, which could cause a fluid deficiency in your plant. Seeing as there are normally thousands of them in a colony, they can destroy a cannabis plant. 

How do you get rid of aphids permanently?

A good way of getting rid of and preventing cannabis aphids is by introducing your plant to some beneficial aphid predators. These range from ladybugs to certain spiders. They will not only feed on any current aphids but also kill any future colonizers. 

What does aphid damage on cannabis look like?

If your plant’s leaves start yellowing and looking unhealthy, then you probably have an aphid infestation. Cannabis aphids also egest, shed, urinate, and lay eggs on your plant. The shedding can be identified by small white exoskeletons that are left behind. 

Aphids on the leaf
Aphids on a plant leaf

Enjoy an aphid free life

Cannabis aphids can be quite a nuisance to cannabis growers. Luckily, it is possible to get rid of them without using harmful chemicals or harming your cannabis plants. 

You can also buy marijuana seeds that are less prone to pest infestation. With cannabis aphids and cannabis mites out of the way, you can focus on growing your tasty nugs to their full potential.

Here at Homegrown, we have a wide range of glorious seeds. Pick our pest-resistant strains and grow a safe, aphid-free, and delectable weed at home. 

About the author: Parker Curtis

Parker Curtis has around a decade of cannabis-growing experience, specialising in soil-less and hydro grows. He’s mastering outdoor, greenhouse, and indoor grows.

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