How To Kill Aphids On Marijuana

How To Kill Aphids on Cannabis Plants

Aphids are small insects that prefer attacking your plants in little groups. They are pretty destructive. They suck the sap from your plants, leaving the leaves wilting and yellowing. Read on to know how to identify an aphids infestation, prevent it, and get rid of aphids from your pot plants.

Aphids are a common plant pest. However, many pests invade cannabis plants that it can be tough to identify aphids. Here’s how you know that you’re dealing with aphids.

Aphids are small-sized pests— between 1 to 10 millimeters in size. They love forming colonies on the back of the plant’s leaves to avoid direct light and hide from predating insects. They come in varied colors, from green, brown, black, red, or white. They also have whip-like antennae.

Also, when aphids suck sap from your plant’s stems and leaves, they leave a dark, sticky substance. The sticky substance, known as honeydew, grows into a sooty mold. The honeydew attracts other insects that feed on predatory insects that might eat the aphids.

If you spot dark patches on your pot’s leaves and stems, you’re most likely dealing with aphids.

The aphid spread pretty fast, and if you fail to contain them at the right time, you might lose a healthy portion of your buds. They begin by winged aphids jetting into your garden, laying eggs on plants. These eggs hatch pretty fast, and before you know it, the young ones have grown into reproductive age, mating around and populating your garden with loads more colonies of sap-sucking aphids.

The female aphids hatch in spring, and by summer, their young ones are laying more eggs, escalating the infestation further.

How does an aphid infestation affect your cannabis plants?

Like most insect infestations, aphids will draw sap and nutrients from your plant, leaving them sickly and forlorn. Due to the strain the aphids put on your plants, the leaves will turn yellow and curl.


The plant will, therefore, be forced to focus its energy on healing and renewal which stunts its growth. An aphid infestation can inhibit flowering and bud formation.


Aphids are not only coming to eat, but they also transfer viruses to your plants. The honeydew they leave behind also attracts more pests that’ll eat your plants and destroy their development.

How to prevent aphids in cannabis

Aphids can invade your garden at any time. The winged aphids can arrive in your garden when you least expect and begin laying eggs that quickly spread. It is, therefore, pretty tough preventing them.


However, there are a few things you can do to make your cannabis plants less prone to aphids infestation. To begin with, you need to avoid stale air and too humid conditions. These are the conditions that aphids, among other pests thrive at. Keep the temperatures in your grow room between 20-25°C, and use fans to encourage airflow.


Apart from keeping ideal conditions in your grow room, here are other tips to help prevent or control aphids.

Bring predatory insects into your garden

Unlike outdoor plants, indoor plants are less prone to aphids. Luckily, nature has a way to deal with the overpopulation of such pests. Predatory insects like ladybirds, crab spiders, and parasitic wasps will make a meal out of the problematic aphids.

How To Kill Aphids On Marijuana

You can buy live ladybirds and introduce them into your garden during spring when the female aphids begin to hatch and summer to eat their young ones before they reproduce.

Predatory insects can save you from using chemical insecticides on your organic grow, but you have to time it well. This strategy will fail if you deploy it too late.

Spray your plants with plant oils

Neem oil is commonly used in protecting plants from pests. Essential oils repel pests, but also kill the pest already on the leaves. Mix neem oil with water and apply it on your plants with a mister. Other essential plant oils you can use include cinnamon oil, eucalyptus, and rosemary.

How to get rid of aphids from cannabis plants

Depending on the level of infestation, you will begin by removing the affected leaves and branches and disposing of them appropriately. Never leave any of these in your garden.


Pruning the affected parts will reveal to you the extent of the infestation and is physical means to destroy huge colonies of aphids. But also, pruning opens up the plant for better air circulation. Improved air circulation inhibits pest infestations and improves your plant’s health.


After pruning, you can wash down the plant with a mixture of water and vinegar.  Washing the plant with the mix will kill the remaining aphids and their eggs on the plant.

Use pesticides

Your choice of pesticides depends entirely on your preference. You can go for organic pesticides like Spinosad, and I hope you try organic pesticides first.


Organic pesticides will not leave any harmful chemical residues in your buds. However, most organic pesticides require multiple applications before they can get rid of the aphids.


If you don’t mind using chemical-based pesticides, you won’t struggle to find one that works. However, limit the use of chemical-based pesticides as they degrade your garden and leave residues in your buds.


Use home remedies for getting rid of aphids from cannabis plants

The best thing with home remedies is that they won’t cost you much—in terms of money and effects on your buds. Home remedies work well to clear the aphids, but you have to get your ‘concoctions’ right. Here are options to try;

Tomato leaf spray: You can use tomato leaves to make an organic spray for your plant leaves. Mix two cups of water with two cups of chopped tomato leaves.

Leave the mixture to steep for a night then sieve off the leaves. Add two more cups to the mix and use a spray can to attack the aphids, concentrating more on the lower side of the leaves. The tomato leaf spray is an effective home remedy for killing common plant pests, including aphids.

Garlic and onion spray: Chop an onion and two garlic cloves, then add two cups of water into the mixture. Squeeze the pulp out and use the mixture to spray your plants.

In conclusion

Aphids can ruin your cannabis plants in many ways. And it gets worse because aphids multiply pretty fast. Keep an eye on your plant so you can save them before the pests destroy them.