Marijuana pests and diseases – bugs, mites, aphids, thrips, curled leaves and other plant issues

Every garden, no matter what type of plants are grown in it, should be protected from pests and pathogens.

If you’ve made the decision to grow your own cannabis plants, protecting them from pests and other growth problems is something you’ll have to figure out beforehand. That’s because taking a preventative approach will help give your plant the necessary strength and health it needs to fight off anything that attacks it.

In order to know how to protect your plants you’ll first have to get familiar with which pests attack the marijuana plant and what other problems can arise while the plant is growing both indoors and outdoors.

If you can’t manage to prevent these pests from attacking the plant in the first place, you’ll need to familiarize yourself with the methods and remedies which are best suited to help you eliminate these pests and pathogens and apply them as soon as possible, to prevent further infestation.

Common Pests that Attack the Marijuana Plant

Small insects and other garden pests love hanging out on your Marijuana plants. They can affect your harvest very badly and even destroy your whole crop.

There are a lot of pests which can endanger your marijuana plants. If you’re a cannabis grower, you’ve probably heard of spider mites, thrips, caterpillars, aphids and more, but even if you’re new to the whole process, soon enough you’ll start to hear about these pests, and none of it will be good news.

Fortunately for you, even if they occur, if you manage to catch them on time and stop them from spreading you’ll be able to avoid suffering a lot of damage and will be able to save your crop.

Let’s have a look at some of the most common pests that can attack the Marijuana plant, their common symptoms as well as ways to identify and successfully treat them.


Aphids are among the larger pests that attack the marijuana plant. They can be seen with a naked eye, and without any magnification.

They can be green, yellow or black in appearance and can grow up to the size of the tip of a pencil.

They start out as eggs underneath the leaves, and eventually they hatch, start feeding on the leaves and cause problems.

Cause and Symptoms

Your plants can get infected when winged aphids, also known as colonizers land on your plants and start laying eggs. Winged aphides are also known as blackflies, because of their color and because they look like tiny flies.

Although they often go undetected until they start making damage, causing the leaves to pucker and seem distorted, if you observe your plants closely and frequently you might notice the black winged aphids flying around or see a colony of green/yellow aphids under the leaves and on the stems of your plants.

Another typical symptom to look out for is drying or yellowing of the leaves which occurs due to the aphids feeding on your plant until it becomes too stressed and can no longer bear the infestation.

Aphids Remedy

Although it’s difficult to prevent aphids from attacking your Marijuana plants, especially your outdoor ones, there is a quick and easy way to get rid of them once they do.

All it takes is spraying your plants with a mixture of:

  • 1L of water (although most need no more than 250 ml to cover all their plants)
  • Dish soap
  • A pinch of cayenne pepper

Mix those three ingredients in a bottle and spray it all over your plants, particularly under the leaves. Make sure to spray in your growing medium and around your pots as well, to make sure you’ve covered every spot.

Spider mites

Spider mites are also pretty easy to identify. They have oval bodies and look like small spiders.

They use up all the chlorophyll from the plant and interrupt or slow down the plant’s growth. They are quite a common pest that affects your Marijuana plant, and they can be quite difficult to get rid of.

Cause and Symptoms

Spider mites are very tiny and can often be found under the leaves of the Marijuana plant. They eat the leaves and leave tiny bite marks, which look like orange, yellow or white speckles on the leaves. This is one of the main signs of a spider mite infestation, and a reason to act quickly.

Spider Mites Remedy

Spider mites can be very common, both in indoor and outdoor plants, especially those growing in soil.

Although they can be difficult to get rid of, there are a few steps you can follow to eliminate them for good. Early detection is key, when it comes to the successful elimination of the pest, which is why you need to inspect your plants frequently.

First off, you’ll need to turn on the fans, and turn down the temperature below 25 degrees, making it harder for them to reproduce. After this step, you’ll need to spray the affected leaves with either an alcohol and water solution using 40% alcohol, or with some of the other commonly used products available on the market, like potassium soap, neem oil, pyrethrum oil, SM-90 or Ecotenona.


Thrips are small insects that come in many different forms. While they are young they have a wormy appearance and they rarely move, but once they mature, they become fast-moving golden or dark winged insects.

Cause and Symptoms

Thrips are a common problem that Marijuana growers face, especially those with indoor grow rooms. They bite the leaves of the Marijuana plants, leaving silver or bronze snail-like trails or spots on the leaves as they suck out the plants’ minerals and nutrients.

Other symptoms include: dry and brittle leaves, shiny spots on the leaves, and damage to leaves and buds.

Thrips Remedy

Even though there are a lot of possible ways which you can use to get rid of thrips, if you’re looking for 100% natural ways to stop the infestation and eliminate them quickly and efficiently, then some of the best remedies to use include:

  • Yellow sticky traps, which work for other insects as well
  • Neem oil
  • Spinosad and other organic insecticides and
  • Lady bugs.