bugs in my weed

Pests, Bugs & Viruses

Unfortunately, bugs and other garden pests can totally mess up your marijuana harvest!

This page aims to be a comprehensive resource on the different types of bugs / pests / mold that can affect your marijuana crop, along with tips for preventing and solving each problem.

Pests that can affect your marijuana plants include aphids, fungus gnats, thrips, green flies, black flies, mosaic virus, spider mites, caterpillars, inchworms, whiteflies, white powdery mildew / white powdery mold, stem rot, and even mammals such as deer or cats!

If you want a list of safe, all-natural pesticides that can get rid of most of the pests on this list, check out this page:

It’s time to fight back against cannabis bugs, mold and pests!

Quick Tip! Whenever you spray plants with anything, make sure to get the undersides of the leaves too, as this is where many pests like to hang out! A one-hand pressure sprayer / mister is also really helpful for spraying leaves.

Aphids live under leaves & have different forms depending on their stage of life

Barnacles / Scale Insects
These bugs that look like barnacles and stick to the plant on stems and underneath leaves

Broad Mites
These mites are so small you will likely never see them even under a magnifier. However, you can tell your plant has been infected because your new leaves will be blistered, twisted and glossy. The overall plant will also be growing poorly and if it’s flowering the buds may turn brown. Broad mites are often mistaken for other problems like nutrient deficiencies, heat stress or pH problems.

Bud Rot or Mold
When bud rot strikes, certain buds may start looking sickly overnight, with leaves turning yellow and/or bud becoming discolored. When opened up the inside of the bud is dead or moldy.

Caterpillars, Inchworms & Cabbage Loopers
Caterpillars and worms eat holes in leaves and leave droppings that look like black specks

“Regular” crickets will munch on your leaves while “mole crickets” can tunnel under your plants and disturb their roots!

Mole Cricket – these can tunnel under your cannabis plants like moles

Fungus Gnats
Fungus gnats look like tiny dark flies. They hang around soil that stays wet for long periods of time, and their worm-like larvae crawl around in the wet top soil. Plants start getting sick if a gnat infestation gets out of control.

You’ve probably seen these before, but these seemingly harmless garden creatures will happily eat your cannabis leaves!

These bugs come in almost every color known to man so sometimes it can be tough to tell what they are just from looking. However, they all make clusters of spots on your leaves where they’ve sucked out all the sap, so if you see spots like this you know you’ve got leafhoppers!

Leaf Miners
Leaf miners are larva that actually live inside your leaves and tunnel through them to eat!

Leaf Septoria / Yellow Leaf Spot
This fungus causes round yellow or brown spots, with symptoms often starting on lower parts of the plant

These tiny white bugs look “hairy” and are found crawling on leaves and buds

Each species looks quite a bit different as an adult. Some look like pretty leaves. As youngsters, they create white and fuzzy patches that look like cotton on their butts and on your plants. Planthoppers suck the life out of cannabis plants if they start a colony.

Root Rot
Root rot is a common problem in hydroponic systems though overwatered plants in containers often display similar symptoms. Plants with root rot wilt and leaves may become discolored. In the reservoir the roots turn brown, smelly and slimy.

Russet mites are so small you can only see them with a magnifier unless there are thousands of them infesting your plant. They live the the crevices of leaves, stems or buds.

Slugs / Snails
Slugs and snails usually come out at night, leaving holes in leaves with scalloped edges from their individual bite marks. They also leave slime trails on leaves and on the ground.

Spider Mites
Spider mites are often caught from another grow room, and their bites leave small white speckles all over your leaves. They’re so small they can be hard to see, though the best place to look is underneath leaves. You may see webbing if there are enough of them living on the plant.

​ Thrips leave irregular bronze or silver marks that may look like “dried spit” or tiny snail trails. Their young look like fat, tiny worms.

Tobacco Mosaic Virus
It’s not known whether mosaic virus has jumped from tobacco to cannabis plants, but in this article I’ll share what I’ve learned so far…

Whiteflies/ White fly
Whiteflies look like tiny white moths and hang out under your cannabis leaves

White Powdery Mold
WPM leaves a white powdery substance that looks like flour or powder on leaves and stems

This easy picture guide will help you quickly diagnose your sick plants. Learn how to get rid of the most common marijuana pests!

Harvesting Cannabis With Bugs Or Mildew

Common Outdoor Cannabis Pests

Besides police, neighbours and crop-thieves, the cannabis plant has a lot of natural enemies. Indoor cannabis cultivation allows a grower to completely control the environment and prevent anything from entering the grow space. Growing a cannabis plant outdoors however, there’s virtually no chance of getting away without at least some attention from bugs and fungi. Infestations are usually kept in check perfectly by predator insects, but unfortunately these won’t remove every single aphid or mite.

Most Important Outdoor Pests And Fungi

Of the numerous tiny animals out to get your precious cannabis plant thrips, whitefly, spider mites, gnats and aphids are by far the largest threats. These pests can all be warded off by using natural enemies during the grow, but often you’ll discover a bunch of them, or their eggs, tucked away under a branch while harvesting. Finding pests while harvesting cannabis is never fun, but smoking bugs or throwing out otherwise good buds aren’t very appealing options either. Fortunately it is possible to remove the majority of these bugs quite easily by washing your buds directly after harvest.

These bugs came off a few colas. Even if they don’t kill your cannabis plant, you’d probably still rather avoid smoking them.

Unfortunately botrytis can’t be fixed and will leave you in complete damage-control mode, clipping away affected areas and hoping it doesn’t spread. Learn more about preventing mold and bud rot when growing marijuana in our blog article on this subject. Powdery mildew however, can be fixed because it doesn’t grow deeper than the surface of a cannabis plant. Washing off powdery mildew is actually quite easily removed during all cannabis plant stages, we’ll discuss how to remove it at harvest in the following section.

Harvesting Cannabis And Washing

Washing is a great way to remove bugs and powdery mildew from your cannabis plant. Everyone has their own crop harvesting techniques when it comes to washing, but the general workflow is very straightforward: you gently wash your buds with water.

How To Wash A Cannabis Plant

Let’s assume you’ve just cut down your outdoor cannabis plant and started trimming it. All looks well from a distance, but now that you’re up close you see a bunch of aphid eggs all over a few of the lower buds. Let’s say you also found some powdery mildew, just to make things worse.

This picture shows the three general steps to washing your buds. By removing mildew and sterilizing your buds, followed by a wash with clean water, your buds will be pest and mildew-free!

Preparing Your Bud Washing Buckets

In the first bucket you’ll wash off powdery mildew, leaving a bunch of nasty residue in your bucket. This will be your dirtiest bucket, so you’ll replace this one the most often. Using alkaline water will be your best bet to clean the buds as powdery mildew does not like an alkaline pH range. A sudden shift in pH will also shock the bugs on your cannabis plant, which will hopefully cause them to fall off in this first bucket.

The gunk in this water is powdery mildew, you’d be surprised how easily the spores come off your cannabis plant with a little wash

Avoid pre-squeezed lemon juice, bottles like this often contain oils that can absorb some of your cannabinoids.

This bud is in the middle of step two and is almost ready for drying!

Washing Workflow Variations

The washing workflow we outlined in the previous paragraph is a global, universal type of workflow, but washing is one of those things every grower does differently. Depending on the strain of cannabis plant, time of year, soil quality etc. you might want to modify your washing regime. One of the most common variations is to use the same bucket for the first two steps outlined in the last section. Taking this route would mean using one bucket with baking soda, lemon juice and hydrogen peroxide for the first round of washing. Because the first bucket always gets dirty quickly it will usually need to be replaced several times, making this a less resource-efficient approach than using two separate buckets. If you are 100% sure your cannabis plant does not have any powdery mildew however, you can even skip the baking soda bucket.

A lot of growers also prefer leaving out the hydrogen peroxide, as it is does not sound very biological. Despite the fact that the human body produces hydrogen peroxide itself, a scary chemical name can make substances like this feel quite dangerous. We prefer using hydrogen peroxide to be sure our wash is successful, but washing without hydrogen peroxide is also a perfectly viable option. Lemon juice essentially fills the same antimicrobial role as hydrogen peroxide, but we like to add in as much certainty as we can.

Another popular modification to this workflow is adding more washing steps after the baking soda, lemon juice and hydrogen peroxide. While a single wash will generally take care of the already low concentrations on your cannabis plant, adding a second or even third washing step can be a good way to ensure a super clean smoke. We prefer leaving it at one final washing step to prevent more trichome damage, as we’re using low concentrations anyway. You can also perform the final wash in the sink by carefully washing your buds under a room temperature tap. This might be a bit rougher on your buds and might cost you a bit of trichomes, but it does make washing a lot quicker and easier.

For the “quick and dirty” approach, simply wash your buds in the sink under a room temperature tap.

Drying Washed Cannabis Buds

After washing your freshly harvested cannabis buds, you’ll have some soaking wet flowers on your hands. If this is your first time washing buds this is probably the point where you start to think you’ve wasted your entire harvest. But don’t be alarmed, it might take a few extra days to dry, but your buds will be fine.

Blowing a fan under these buds for an hour or two will get rid of the big droplets of water. After those are gone you can dry your buds as you normally would.

Final Thoughts On Washing Cannabis Buds

We hope this article has given you an idea on how and why you should wash your cannabis buds. By breaking down the different steps involved in washing buds, you should now be able to figure out which buds are salvageable and how you can develop your own unique method

Be thorough though, or you might be unpleasantly surprised!

Because harvesting cannabis is already very time consuming however, most growers will avoid washing buds as much as possible. The risk of breaking off trichomes is also always present, so washing buds can potentially diminish the potency of your harvest. We prefer to look at washing cannabis buds as an extremely effective way to save a crop after finding pests or mildew near the harvest date. Whatever you do, wash or no wash, we wish you the best of luck with your next grow, and hope your cannabis plantwon’t have any of the problems mentioned in this article at all!

These bugs came off a few colas. Even if they don’t kill your cannabis plant, you’d probably still rather avoid smoking them.