How to Kill Aphids on a Cannabis PlantOctober 16, 2019
Finding any bugs on a cannabis plant can be devastating. Your first instinct is to panic and find the quickest way to treat the problem. Each pest should be treated in a different way. In this guide we will cover how to kill aphids on a cannabis plant.
There is a process to treating any bug problem. Identify what the bug is, find out how it got in to the grow room, and then treat the plants accordingly.
By the end of this guide you will know how to diagnose aphids on your cannabis plant, how to treat them, and how to prevent an aphid infestation arising in the future.
- What are Aphids
- What do Aphids do to a Cannabis Plant
- Symptoms of Aphids on a Cannabis Plant
- How to Kill Aphids on a Cannabis Plant
- Pesticides for Treating Aphids on a Cannabis Plant
- Treating Aphids without Pesticides
- Bud Washing After Harvest
What are Aphids
Aphids are a small bug, that range in colour and size, but are a very destructive pest on a cannabis plant. The most common type of aphid to be found on a cannabis plant is the green type, that can also been called “Green Fly”.
Aphids are sap sucking insects, that will bite into your plants, and suck the juices from it. This can cause massive damage to your crop.
If you suspect that your plants may be suffering with an aphid problem, you should act quickly to fix it. But first, you need to make sure that the problem is aphids, correct diagnosis will give a much better chance of successful treatment.
What do Aphids Look Like
This is an adult aphid, they all look similar to this. Some may have wings, some may be a different colour. They will all cause unwanted damage to your plants, and in high numbers, they can completely kill a crop.
Once they get into your grow room, they will lay eggs, and it within a week and infestation will start.
The Life Cycle of Aphids
Each type of aphid will have slight differences in their life cycle, but there are some traits they all share.
If a wingless adult female aphid gets into your grow room, it will lay 50 to 100 eggs in a week. When these eggs hatch, the baby aphids will grow and be able to reproduce within a week, when they will lay around 12 eggs per day for the rest of their lives (around 30 days).
If left untreated, aphids can quickly grow into huge numbers, and they will cause your plants growth to slow down, or even stop.
What do Aphids do to a Cannabis Plant
Aphids will feed on your cannabis plant by biting into it, and sucking the juices out of the plant. This takes much needed food from the plant, and it will soon start to suffer with stunted growth.
Another major problem caused by aphids is the increased risk of sooty mould. The aphids will produce a sap like liquid called honey dew. This increases the chances of black sooty mould, and also increases the chances of more insects coming into the grow room.
Aphids provide ants with this sugary honey dew, and ants like it so much, they will defend the aphids from predatory insects so they can make more of it.
Luckily, aphids are not difficult to treat, and they are not hard to spot. Once they have been identified, they can be removed from the grow room within a few days.
Symptoms of Aphids on a Cannabis Plant
Aphids are big, and the problem will begin by a female getting into your grow room. She will begin to lay eggs, and within a week they will hatch, and the infestation begins.
If you’re lucky, you may be able to spot the adult female on the plants before the eggs hatch. If you see an actual aphid, act immediately, check on the underside of the leaves and look for more, this is where they will spend most of their time.
You may not see the aphids, but instead notice small white dots appearing on your leaves. This is from where the aphids have bitten into the leaves and sucked out the juices. This leaves a small coloured patch on the leaves.
In extreme cases, large amounts of aphids will produce a large amount of honey dew, and this will encourage the growth of sooty mould.
Sooty mould is black, and can cause damage to your plants, and if you smoke cannabis infected with mould, it is bad for your health too.
Early diagnosis and treatment is key to killing aphids. If you have these symptoms, and have seen an aphid on your cannabis plant, then you need to know how to kill them, and stop them from coming back.
How to Kill Aphids on a Cannabis Plant
Like any pest invasion in your grow room, the bugs got in somewhere, or some how. It is a waste of time treating your plants, if you don’t find out where the bugs came from.
The bugs mostly likely came from an external source. There may be easy access through a vent, some ducting, or they might even be getting in from you, off your clothes, when you check in on your crop.
The first step, in treating any bugs or pest problems with your cannabis plants, is to find out where they came from.
Find the Source
Aphids can get into your grow room in many ways, you need to make it harder for them to get into the grow room.
Check your intake vents, and see if there is a gap where bugs can get in. In some cases, growers will have ducting coming into the tent directly from a window, or external vent. If this is how your intake vent is, then it may be a good idea to cover the ends of the vent with some nylon stockings.
You can use many things to stop bugs coming in through the vents, even an old carbon filter will work. The harder you make it for bugs to get in, the less likely you are to have a problem.
Always wash your hands and take any outdoor jackets off before going to the grow room, especially if you have just been outside. Some growers will be extreme, and shower before visiting their plants. This is up to you. Prevention is better than cure. The cleaner you are before visiting the grow room, the less likely you are to find bugs on your plants.
Aphids come in many forms, and some of the adult females will develop wings, and fly. Any flying insect can be caught by sticky traps, and they are a necessity in the grow room for bug prevention.
If the initial aphid that started the problem, in your grow room was a flying one, a sticky trap may have caught her on the way in, and you wouldn’t have a problem at all.
Add some sticky traps to your grow room. Some hanging above the canopy, and some below the canopy too. These can catch thrips, aphids, white fly, fungus gnats, and can really help prevent more pests getting into the grow room, and catch them before they start laying thousands of eggs.
Pesticides for Treating Aphids on a Cannabis Plant
Chemical pesticides are a very effective way to kill aphids on a cannabis plant. They are designed specifically to kill aphids, and their eggs, but, chemical pesticides can be harmful to the environment, and to you as the grower and user of the cannabis.
Only use chemical pesticides if you have to, and never use them during the flowering period.
When using pesticides of any kind, you should wear a mask to prevent breathing in any of the chemicals. Also, treat the plant on the top, and underneath the leaves. Don’t spray the plant too much, only to wet it, you don’t want water dripping off it, that’s too much.
If you are growing indoors, you should also remove the plants from under the lights, or turn the lights off during treatment to prevent light burn.
Chemical Pesticides for Killing Aphids
Bug Clear Ultra will kill most bugs on a cannabis plant, aphids being one of them. It does say on the bottle that it can be used for fruits and flowers, but that does not mean cannabis flowers.
Using pesticides likes this on fruits you can wash, and ornamental flowers is fine, but you should not spray any chemicals at all on the flowers of a cannabis plant.
Only use pesticides like this during the vegetative stage, and if you have a big pest problem. There are cheaper and more environmentally friendly ways to treat a cannabis plant pest problem.
Aphids are pretty easy to get rid of by using some things found at home. You can begin by taking the plant outside, and washing it down with a hose if this is possible. This will remove the larger bugs quickly and easily, with no pesticides involved.
You can use an epsom salts spray, or make a garlic and pepper spray to treat most bugs on a cannabis plant. It takes consistent treatment, after treating your plant, it is a good idea to treat it again 3 days after, and then 3 days after that.
Treating Aphids without Pesticides
If your plants are heavy into flower, you will not want to use any kind of spray or chemicals on them. Doing so may taint the flavour of the buds, or add harsh, toxic chemicals to them.
There are a number of ways you can treat aphids on a cannabis plant without using pesticides. Some of the methods may not kill them entirely, but it will keep the numbers below a level where it is too harmful to the plant.
Just by simply taking the plant outside and washing it down with a hose will remove a lot of the bigger aphids. If you do this just a couple of times, you will be able to bring the numbers down to a maintainable level.
Not all insects are bad for a cannabis plant. Some insects will not eat the plant at all , but instead eat insects that live on it. These insects are called “Predatory”. They are carnivorous, and will not eat your plants.
If you have a pest problem late in flower, using predatory insects is a great way to solve the problem. You can either go out and find these insects and place them onto your plants, or it is possible to buy them online, and have them delivered.
Lady birds, aka lady beetles, are notorious for killing aphids and other bugs on a cannabis plant. They only eat the bugs, and will not eat your plants. You can buy ladybirds online, and in some grow shops, and they are a good natural way to treat any bug on a cannabis plant. Just buy them, and release them into the grow room.
Having extra bugs on your buds will make them dirty. The insects will produce waste, that will be left on your flowers. If you have had any bug problems on your cannabis plant during flower, then you should wash your buds after harvesting them.
For insects to live in your grow room, it has to be a suitable environment for them. If the conditions of the grow room are not suitable for aphids, they will not live there.
If you turn your fans up, and have a strong breeze blowing at the plants, the aphids will have trouble holding on to the plant and laying eggs. This will reduce the amount of eggs that are laid, and in turn reduce the amount in the grow room.
You can also increase the level of CO², and heat in the grow room to kill aphids on a cannabis plant. Slow down the extractors, and add some extra CO² around the plants. After a few hours, the aphids will not be able to breathe, and they will begin to die.
Making the grow room hotter than it should be is not always good for the plants. But a short period at around 30°c will not cause too much stress to the plants, but will really stress out the aphids. If they are too stressed, they will leave the grow room or die. Also, being stressed will prevent them from laying eggs.
Bud Washing After Harvest
After harvesting a cannabis plant that has had a bug problem, even if you haven’t used pesticides, you should wash the buds before drying them.
The insects that have lived on your plant, would have produced waste, that will be left on your buds. There may be insect carcasses, eggs, there will definitely be feces and urine.
You don’t want to smoke this, and you don’t want it in your extracts either. Washing the buds after harvest will remove a lot of the contaminants that gather on the plants during the flowering period.
Finals Thoughts on Aphids on a Cannabis Plant
It is important not only to treat the aphids, but to find out how they got into your grow room in the first place. Treating bugs on a cannabis plant can be stressful to them, so you don’t want to treat them more than you really have to.
Find out how the bugs got in there before you do anything. And then move on to killing the invaders.
Bugs happen, it is part of nature, and it can be fixed. If you need any help at all, then let us know in our cannabis growers forum. We will help you identify your cannabis plant problems, and get you on the right track to a good harvest.
Thanks for reading, Happy Growing.