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Aphids Bothering Your Plants? Here’s How You Kill Them! 

Added 11 January 2022

If you grow cannabis, you must always be on the lookout for pests — they can significantly damage your crop to the point of no return. 

Of all cannabis pests, aphids are the worst because they are stubborn enough to attack and suck the life out of your plants. 

Aphids don’t give up — they are determined to kill your plants. Plus, they get ample support from ants! 

Both ants and aphids have a great relationship because the ants love the honeydew the aphids secrete. 

So, how do you prevent these pesky pests? And, how do you get rid of them if they have invaded your grow room already? 

Here’s everything you need to know about protecting your cannabis from aphids.

What are Aphids?

Aphids on a plant

Aphids are parasite insects belonging to the Hemiptera order; they are small and live by sucking the plant. They love the sap produced by the plants and enjoy sucking the living daylights out of them. This is what makes them one of the most destructive pests for cannabis plants.

Their parasitic nature deprives your cannabis of vital nutrients, affecting the plant’s growth and yield. 

Apart from them hogging your plant’s nutrients, they also carry various viruses and diseases that can disrupt your plant’s growth cycle. In fact, aphids are on par with spider mites because both of them destroy the plants if they aren’t eliminated on time. 

They also secrete honeydew, a sugary juice, that attracts bees and ants, which can be a nuisance to deal with in the grow room. Although we suggest you never hurt the bees — they are good insects.

Perhaps the worst thing about aphids is how fast they multiply, so if you see one, expect to see hundreds in a couple of days because their populations increase at rapid speed. They are even faster during summer when the temperatures are high. 

As a grower, you should be scared of aphids because they are brilliant. So much that they produce babies instead of eggs! They do this since they don’t have to wait and hatch the eggs! Furthermore, a small aphid nymph can become a full-grown adult and start reproducing in just a week!

Therefore, it can sometimes seem like the aphids appeared out of nowhere. And, once they do, they just don’t go away. 

How to Spot Aphids on Cannabis?

Aphids and ants

One way to spot aphids is to look for ants. If you see ants on the leaves, you can be sure there’s an aphid colony somewhere.

Aphids love warm climates and environmental dryness, which is why they are most often found on cannabis plants worldwide. 

They are easy to recognise, too, as they are pretty small — 2-3 mm — of different colours like black, green, and yellow. Their body is oval, consisting of a head, thorax, and abdomen. While some have two pairs of wings, some don’t. 

One of their distinguishing features is two appendages in the rear that secrete sugary juice to deter predators. 

You can usually find these parasitic insects under the leaves and on stems in colonies of hundreds (scary, yikes!). Kill aphids on cannabis as soon as you spot them. 

What are the Symptoms of Aphids?

Pests are pests, but aphids have a unique way of affecting your cannabis plant. Here are a few of the symptoms that signal aphids infestation in your grow room.

  • Nutrition Deficiency

Cannabis nutrient deficiency

Aphids suck on your plant’s nutrients, but they don’t leave any marks on the surface like spider mites. So, instead, you need to look at your plant’s health. 

Aphids cause a nutrient deficiency in cannabis, making the leaves turn yellow, dry out, or curl up. So, you need to prevent aphids on cannabis as much as possible.

  • Presence of Ants


Ants are another symptom of aphids infestation on cannabis because aphids secrete a sugary substance the ants use. As a result, aphids and ants form a symbiotic relationship where the aphids feed the ants, and ants protect the aphids. 

So, if you have a lot of ants in the grow room, it’s time to turn the leaves over and prevent aphids on your cannabis.

  • Diseases 

Sooty mold

Perhaps the worst symptom of aphids is that they cause diseases to your plant. This is because their droppings contain various viruses and microbes harmful to the plant. 

Plus, they can cause sooty mold and fungi to grow on the stems and leaves. In such cases, we recommend using copper oxychloride to treat your plant. 

Always be on the lookout for these signs on your cannabis plant, and never take them lightly. 

How to Prevent and Kill Aphids on Cannabis?

Aphids and ladybugs

Now you know how to spot and recognize aphids, but that’s not enough. It’s often too late to save your crop if aphids have infested it. So if you want to protect your plants from aphids, you need to first prevent them from colonizing your plant. 

And in the worst-case scenario where they do enter your grow room, you need to be quick with remedies to kill them. 

So, here are a few ways you can prevent and kill aphids on your cannabis plants.

  • Keep the Grow Room Clean

This goes without saying — keep your grow room clean if you want to prevent aphids on your cannabis plants. Prepare a schedule to clear out the decaying plant debris and pull out dead leaves and debris from your grow room, so no aphids get attracted to your grow room in the first place.

  • Host Friendly Insects

Not all insects are destructive for your cannabis — some can act as your plant’s bodyguards! So, we recommend bringing in some insects that are aphids’ natural predators.

Insects that protect cannabis are ladybugs, crab spiders, and lacewings. They primarily prey on aphids and keep their population under control. 

And, if you’re someone that appreciates nature, you’ll find them cute — just another reason to get these insects in your cannabis grow room. (But don’t confuse crab spiders with spider crabs — those things are terrifying!)

  • Use Natural Pesticides

Keeping your grow room clean will prevent aphids on your cannabis, and natural predators will kill those brave enough to enter your grow room, but what if they don’t work?

It’s time to bring out the big guns — pesticides. 

We only recommend using natural, organic pesticides as they are entirely harmless to your cannabis plant, yourself, and pets. Chemical fertilizers can be dangerous for everyone, and they may leave a nasty flavor on the buds. 

So, if you ever get aphids infestation in your grow room, you need to be quick and use organic pesticides, such as the following:

  • Spinosad
  • Horticultural oils (vegetable oil, canola, soybean, or cottonseed)
  • Rotenone
  • Nettle flour
  • Tobacco-based insecticide (nicotine acts as poison)
  • Neem oil
  • Potassium soap

Using these pesticides is quite simple — just spray them regularly, as directed, on the affected areas of the plant once the lights go off or the sun goes down (to prevent burning the leaves). 

You may have to bathe the plant after spraying some of the pesticides as they leave a thin film on the plant, and as much as possible, avoid spraying on the buds or plants in the flowering stage as it can affect the flavor and smell.

Also, if you are growing cannabis for others, only use pesticides that are non-allergic.

  • Remove the Damaged Parts

In the end, once you have unleashed your army of friendly insects and sprayed enough pesticide to kill aphids, it’s time to clean the plant. Remove any damaged leaves or those that display signs of stress or mold on them as they may affect your plant’s growth. Doing so also removes any traces of eggs or insects.

  • Get Rid of Ants

Ants generally act as pack leaders by tending to aphid herds indoors and outdoors. Amazingly, both pests form a quid pro quo relationship.

How? The aphids feed on the plants and suck the juices. Meanwhile, they also transmit various diseases to the plants in the process. The aphids convert the sap into a sweet substance or honeydew.

While we humans detest aphids, ants, on the other hand, love aphids because they hunt for the very honeydew the aphids secrete.

Ants are determined to protect the aphids from humans and other predators. Although ants do not hunt for ladybugs, they will attack them if they are found troubling the aphids.

Therefore, a sure-shot way of preventing aphids is to control ants in the first place. This is pretty easy for hydroponic growers since there's no soil for the ants to hide. However, if you're growing cannabis plants in soil, your priority must be to prevent ants. The same goes for those growing cannabis plants outdoors as well because it's pretty easy for the ants to invade your plants and support aphid colonies.

Here are a few things you can do to get rid of ants in the soil and plants:

  1. First, identify the ants' preferred location. Typically, you'll see holes with several ants hanging out there.
  2. Next, start filling the holes with freshly powdered cinnamon or water diluted with cinnamon to force the ants out of the soil.
  3. You can also use neem oil diluted in soap water to get rid of the ants. The ants will move out in both cases due to the strong scent.
  4. If you notice the ants coming back, spread some diatomaceous earth all over the soil. Diatomaceous earth targets the exoskeleton of insects due to its abrasive nature, but it won't harm the roots.
  5. If nothing works, make a 3G spray solution — Ginger, Garlic, and Green chilies paste mixed in soap water — and spray on the soil and leaves.

Avoid spraying leaves when the lights are off because it can increase the humidity and create other issues. If you have no choice other than to keep the lights on while spraying, use a fan to dry the leaves immediately.

Summary: Aphids Bothering Your Plants? Here’s How You Kill Them!

Aphids are notorious pests that can affect your cannabis plants, but there are many things you can do to prevent them. Keep your grow room clean, bring home some friendly insects that prey on aphids, and regularly rinse your plants in organic pesticides. 

These techniques are enough to make your plant a hostile environment for aphids and prevent an infestation.

Stay tuned to know more about protecting your cannabis plants from such notorious pests!



Hi there, nice,
these females lay pregnant females and no males, this is called parthenogenesis. Since they do not lay eggs the frost can kill them :+1: a cold can with spray does the trick, yep