What are spider mites? A closer look at the tiny pests that could ruin your cannabis yield

Growing your own cannabis is rewarding, but it’s a great deal of work as well.

One of the things you’re going to have to deal with from time to time is plant pests affecting your yield. Spider mites, in particular, love feeding on chlorophyll and sap, and will spread webs all over your cannabis plants.

But what are spider mites? And how do you keep them from destroying your crop?

Spider mites are the most common cannabis pests out there. So, in an effort to keep our enemies close, we took a deep dive into what makes these little creatures tick—their likes, their dislikes, and their feeding habits.

Here’s what we learned.

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What Are Spider Mites?

Spider mites are tiny bugs that often hide in cannabis buds, ingesting the liquid in the plants and spinning webs. As they drain the buds of their key nutrients, you’ll find yourself looking at rotting and a ruined yield.

They seek dark places in the cannabis plant and reproduce frequently. If you don’t take the proper measures to get rid of them, they can quickly become the bane of your cannabis-growing existence.

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How to Spot Spider Mites

A spider mite is only about 0.5 mm in size and they’re either bright red or black with 8 legs – hence the name. Since they’re so small, you have to look closely to see them with the naked eye.

They’ll appear as tiny spots running around your plants when out in the open. More commonly, however, you’ll see them on the underside of the fan leaves where they lay eggs and stay out of the sun.

With bad infestations, you’ll see lots of yellow and white dots on the plants, which indicates feeding. You’ll also see more spider mites running all over the leaves.

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What Do They Do to Cannabis?

As mentioned, spider mites feed on chlorophyll and sap, but that’s not the worst of it. If undetected, spider mites will start to lay eggs in the dark crevices of the cannabis plant.

They then cover their eggs in webbing, and this web may end up covering the entire plant if they’re left to reproduce freely. When the eggs hatch, they start to eat the buds from the inside out, which is what causes rot.

How to Prevent Spider Mites from Finding Your Plants

Keeping a perfect growing environment for your cannabis plants is the best way to keep spider mites away, but they’re very common. Keep your space clean and sequester clones before integrating them in with your other plants.

Spider mites don’t like wind, so ventilating your growing area is a good way to keep them at bay. Additionally, try to keep the room at a good growing temperature and keep the humidity at the right level.

Getting Rid of Spider Mites

If spider mites have already found your cannabis yield, don’t despair. In the early stages, you can simply spray the spider mites off of the plants with a water sprayer. Neem oil should take care of the rest, but bigger infestations will require more drastic measures.

For large infestations, you’ll either have to spray your plants with harsher chemicals (which may cause different problems) or throw the infested plants out to save the others.

Needless to say, you’ll want to catch a spider mite infestation early for the best chance of saving all your plants.


Spider mites are very tricky to deal with despite being so common in cannabis plants. However, if you catch them early, you shouldn’t have any issues with your yield.

When it comes to growing cannabis, it’s one plant pest after another, so you need to pay close attention to your plants as they grow to be sure spider mites or other pests have not found them.

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