Pests and deficiencies

Every grower, especially in the beginning, will bump into some problems and most of the times they are being caused by diseases or pests (insects/bugs/fungus). Luckily for every problem there is always a solution but it might be tricky to find the right solution for that particulair problem. You need to know: The solution for one can be the cause for others…

For example: Bud rot can be treated by lowering the humidity drastically while other pests love dry conditions.

Most problems in a grow are caused by the wrong growing conditions. So by offering your plants the perfect place to grow, you decrease the chances of problems big time! However even then, there is a chance you will encouter some struggles.

What can I find on this page?

Also check out our “Ultimate pest guide for cannabis” to find out how to treat the most common cannabis pests!

The first step to treat a disease is by simply avoiding them.

Before the grow, make sure the growing conditions are perfect. Think about things like:

  • Healthy grow medium

Make sure the medium your grow in is able to drain the water easily. Use airy soil and make sure there are no chemical additions to them. Dark airy wood soil is good for cannabis plants when growing in the ground/outdoor.

  • Good water (Right PH and PPM)

Using the right water is very imporant is this is what your plant lives on. Make sure the PH is around 6-7 to get good results. The PPM measures the harshness of your water (amount of minerals and solutions). The tap water you’ll use should not be higher then 350-400 PPM. (More about PPM and how to measure it)

  • Temperature

The right temperature will take care of a healthy plant. It’s metabolism and other biological processes only work properly with a temperature of 20-25C for younger plants. When they grow older temperatures can go up to 30C. Make sure the temp’s at night won’t go lower then 20C.

  • Humidity

The humidity for a cannabis plant is quite important. Cannabis loves a very high humidity, especially in the growing phase you can make it’s environment as moist as possible. However once she starts to bloom and produces buds you should lower it to around 40-60% to avoid fungus and problems like budrot and powdery mildew. (they love a high humidity)

  • Nutrients

A cannabis plant does need certain nutrients to improve natural processes and their overall growth. However you need to make sure to give the right (organic) ones and in the right amount. Not enough/wrong nutrients will result in stunted growth and fluffy plant/buds but too much nutrients will cause something called “Nutrient burn” and leaves you with burnt/crispy leaves while slowly killing your plant.

Recognizing the problem

If your growing conditions are well but you’re still experiencing troubles, it’s important to act quick. We always say: The longer you wait, the bigger the chance it’s to treat the problem. So the first thing you need to do is finding out what exactly you’re dealing with as quick as possible. To help you, we have listed up the most common ones:

Leaf problems/Deficiencies/PH and PPM

Leaf problems (colouring, burnt leafs or leafs dying/falling off) are pretty common and could be quite easy to solve. The trick is finding out what causes a specific problem by looking at the  differences of the leaf. A leaf is the perfect indicator to find out what’s wrong with your plant as it shows unique signs for a specific problem.

Leaf problems are often a result of a problem with the water that your plant is consuming. So thats the first thing to check. Especially nutrient deficiencies and wrong PH will be shown in the colouring of your leaves.  A certain deficiency (of a mineral) will show a unique colouring on the leaf which makes it easier to detect what specific nutrient your plant is missing. Next to that, the wrong PH and PPM levels of the water can also be seen in the colouring and state of the leafs.

A leaf is also able to tell you if it’s over-/under watered or the temperature is too high/low. If your plant is not getting the amount of water it needs, it will show very dark, curling, hanging leaves. So immediatly check out the dryness of your soil and adjust it the right way (too dry, add water and too wet, let it dry for a few days)

If the temperatures are way too hot the leaves will also turn dark/yellow, starts to curl and eventually crumbles down. Too cold? They will also turn dark and it’s possible that some stemps occurs dark purple. Give your plants the right temperatures!

Recognizing deficiencies! (coming soon)

More about PH and PPM


Almost any kind of fungus, mould or rot is being caused by an environment that is not suitable for a cannabis plant. Fungus/rot loves an environment that contains specific temperatures, air circulation and humidity. So the number one rule to avoid or treat them is creating the right environment in your growroom/area. The most important factor in this is the humidity. The right humidity for cannabis plants is:

  • Clones: 70-80%
  • Vegetative phase: 40-70%
  • Flowering phase: 30% and lower

More about the right humidity for cannabis

As you can see in the last phase of the plant (when the buds grow and evolve) the humidity has to be very low. The dense buds will suck up lot’s of moist and it will evaporate very slowly. These warm and moist conditions are perfect for bud rot/fungus.

Did you know: Bud rot is one of the most common problems in the flowering phase? Always keep your humidity low in this period! Find out how to treat Bud Rot!

Next to the common issue called Bud Rot there are multiple other fungus problems that could ruin your plants. Always closely watch every aspect of your plant while you grow, the earlier you detect a rot or fungus, the easier it is to get rid of.

More about fungus/mold found on cannabis plants!

Pests and bugs

If you have been able to keep your plants free from fungus, rot, deficincies and more, there are still some bugs and other insects that could attack your plant. Especially outdoor grows are vulnerable for these little animals. You could get creative with nets like some do, but it’s very hard keep them out. However growing indoors will not prevent any insects from coming to your plants, Some of them are so small that they will find their way in (Some are even carried in by you, on your clothes or material your bring in).

The thing with bugs is that you can’t spray any chemicals/poison around to kill them. These toxic chemicals will will stay on the plants and eventually end up in your dried nugs. One method is to find a natural “enemy” of the insect. This could be the temperature, humidity (climate) or you could find another insect that lives off the attacker of your plant.

A great example is the Ladybug! These little creatures love to eat all kind of small plant-eating insects without harming the plant itself!

Recognizing the bug/insect

However, before you could even start thinking about natural enemies or other ways to treat a pest, you definitly need to know what you’re dealing with. Insects look very familiar to each other but they al have their own characteristcs. Some like to eat plants, others like to eat the plant-eaters. Next to that there are many insects around! No one is able to recognize and know them all so it might be tricky to find out if one is harmfull or not.

However, in our “Ultimate pest guide for cannabis growers” we have listed up al common pests that cannabis growers deal with. Here you can find how to recognize and treat them in a succesfull way.

If the insect you’re dealing with isn’t in our guide, we have the internet! One great tip if you are suffering from a pest is to share it on this reddit page:  What’s this bug? Just share a picture and you’ll quickly be getting responses.

While there are thousands species of bugs/insects, there are a few that are more common to find on cannabis plants. They are somehow more attracted to them. If you have experience with growing, you will have heared about: “spider mite”,”white flies” or  “aphids”. These are well known and researched pests so we have some methods to get rid of them and they are not alone!

Thats why we made a “Complete Pest Guide” which helps you treating particulair animals/bugs/insects.