pythium cannabis

Pythium, The Hidden Terror For Cannabis Plants

Pythium is the unseen enemy of the root zone of cannabis plants both indoors and outdoors. Don’t allow this nasty fungus to turn the roots of your precious marijuana plants into brown foul smelling sludge. Root rot will plague your ganja no more after reading this guide.


Pythium is commonly referred to as “root rot” by most cannabis cultivators. This stealthy pathogen is a fungus with a nasty habit of wreaking havoc on root zones in hydroponic systems and any other damp medium it manages to infest.

Seeds and seedlings are especially vulnerable to the plague of Pythium and cannabis plants at any stage of their lifecycle can be attacked by Pythium should the grow environment be allowed to become habitable by fungus.

The scary truth about root rot is that it is 100% preventable. Pythium is best avoided altogether but should it happen to strike your root zone it can be treated and often cured.

However, simple preventative measures are advisable rather than finding yourself playing botanist come alchemist at 3 am mixing potions of home brewed fungicide to exterminate microbial nasties.

As a root zone parasite, Pythium can often go undetected by the cannabis grower until it’s spread throughout the garden and planning on staying.

By this time Pythium has already been damaging the plant’s roots for quite a while before the above ground symptoms of unhealthy plants grabs visual attention and raises the alarm.


Detecting Pythium in the weed garden can be a real head-scratcher. Outdoor growers and indoor out of the bag soil cultivators are not immune to the blight of root fungus either. In fact, Pythium is even more difficult to readily identify in non-hydro grow ops.

If you happen to be a hydroponics grower then you must be especially wary of Pythium, but you have the huge advantage over all other growers of being able to eye-ball inspect the root zone, well in most active hydro set-ups anyway.

Passive hydro systems like “Hempy Buckets” and most organic grows in soil/coco obviously don’t allow for this.

Brown discolouration and a gungy mass growing in and around the roots is indicative of a text book case of root rot, and the Pythium fungus is responsible for the root zone horror show 9 times out of 10.

Unfortunatevictimised hydro growers that witness this mess will never forget it and never ever want to see it again.

As well as looking disgusting, Pythium also has a foul smelling odour similar to mildew. What adds to the confusion with diagnosis of root rot is the above ground symptoms displayed by infected cannabis plants often mirrors numerous other common problems from over fertilisation to light burn and everything in between.

Leaves can curl, sometimes they drop and sag, all kinds of discolorations from near white to mottled brown spots and every shade of yellow can drive a ganja farmer round the bend with misdiagnosis.


Getting your precious little beans off to the perfect start is the first step towards that final lush cannabis harvest. Germination really is an all or nothing affair so we recommend our Royal Queen Seeds Starter Kit, it’s got everything you need to get your grow on including a propagator, rooting medium and of course a choice high quality feminised seeds.

During vegetative growth, especially when it’s time to transplant, regardless of the cultivation medium cannabis plants are at risk of shock and/or stress if the grower is not diligent. Getting your grow optimally balanced – from nutrients to environmental control, in so far as possible – is the best way to prevent fungus attack.

Pythium loves an overwatered cannabis plant, and if the roots are sitting in a pool of run-off water all the better for this micro-predator root destroyer. Feed your cannabis crop only when it needs to be fed, dialling in an effective wet-dry cycle is crucial.

Hydroponics growers must ensure the water in the reservoir is highly oxygenated, not only to ensure optimal nutrient uptake but also because Pythium perishes in a well aerated medium. Aeroponics cultivators are probably grinning and well they should!

Hydro growers would be wise to invest in a quality air pump to keep that water bubbly and at room temp, as Pythium prefers a lukewarm low oxygen bath to spore in. Ideally, a misty air gap between roots and the reservoir should be the objective to keep the root zone thriving and Pythium free.

Air-pots are designed to facilitate air pruning of roots, plus they work great in both old school hand watered dirt grows and fancy automated hydroponics systems alike. They cost a little more than standard plastic pots but they are also less susceptible to Pythium invasion.

Healthy root zone development can also be encouraged by supplementing your feeding regime with beneficial bacteria and fungi. These days the 21st-century cannabis cultivator is spoiled for choice when it comes to friendly fungi additives.

Some can be costly but even a modest investment in some budget priced Mycorrhiza and/or liquid enzymes will pay dividends come harvest time.


We’ve got good news and bad news when it comes to effectively purging your cannabis garden of Pythium. The good news is Pythium can be treated and eradicated, the bad news is it’s going to cost and it’s always a high a price to pay to defeat an embedded enemy.

Specialist root rot treatment products are available, but virtually all of the effective one’s are definitely in the premium price category. Moreover, and to be perfectly honest, they really only are effective on early diagnosed indoor plants still in vegetative growth.

The nuclear option to guarantee fungi elimination is to scrap the whole grow and thoroughly clean the grow environment and start afresh with new medium and hygienic practices. If Pythium is ravaging seedlings it’s probably best to push the button and clean up your act for the next crop.

Battling a Pythium plague is a war of attrition and even if you eventually prevail the damage caused by Pythium is permanent so the grow will invariably be delayed to allow time for the cannabis plants to regain their vitality and marijuana yields are certain to be impacted negatively.

As usual when it comes to pests and diseases prevention is always the best medicine and Pythium is no exception.

Pythium is a fungus that loves to munch and pollute a cannabis plants root zone. Follow our advice and be prepared to combat root rot in your marijuana crop.

What is Pythium

What is pythium? Causes and prevention of this fungus

When it comes to growing our marijuana seeds, we can encounter several complications that can spoil our plants and spoil our harvest..

✨ What is Pythium?

One of the best known is the Pythium fungus, also known as ‘root rot’, which occurs and proliferates in indoor wet crops, greenhouses and seedbeds. This fungus is characterized by going unnoticed at first and acting very quickly once it has infected the plant, causing its death without you having had time to detect it, and can remain active for many years in the substrate of the soil once contaminated.

In addition to attacking the roots of the marijuana plant, Pythium can be found in irrigation water itself and even in flies and mosquitoes, so it is extremely difficult to control its presence and is highly recommended to anticipate its occurrence

Fortunately, the appearance of Pythium is completely controllable and preventable with proper care, and there are treatments available on the market for this powerful fungus.

✅ Typical symptoms

If you suspect that the Pythium fungus has been able to make a visit to your plantation, be aware of and check the following symptoms before moving on to the attack:

  • The first place this powerful fungus attacks is at the roots of the plant.
  • Pythium prevents the absorption of nutrients, so you will notice that your marijuana plant begins to rot.
  • Starting at the root, the fungus then spreads through the stem to the leaves. For this reason, you may find that the leaves yellow because they begin to wither until, in many cases, they die.
  • The infection caused by this fungus can reach up to 10 cm. above the base of your marijuana plant.
  • If Pythium has affected the seeds, you will notice that they will be soft and blackish in appearance.

▶ How to avoid it or prevent it?

As we have already mentioned, Pythium is a very fast fungus that, once infected, kills the plant in almost a blink of an eye. To avoid ruining all your work, we recommend that you avoid the following conditions:

  • Floor temperature too high.
  • Growing areas with too much moisture.
  • Extreme hygiene in the growing area.
  • A dirty and poorly aerated substrate
  • Overwater the plant. Prevents puddles from forming on the substrate.

On the other hand, if what you are looking for is to prevent its appearance in your new crops. You should keep in mind that:

  • Proper cleaning and hygiene are essential throughout the growing area.
  • Hygiene is also essential in ALL the utensils you are going to use (including your hands). It’s a good idea to sterilize them properly before using them for growing your marijuana plant.
  • A clean and aerated substrate is essential.
  • The temperature must be warm, as the heat encourages the appearance of this type of fungus. A temperature of 30 degrees and a humidity of 80% are the perfect conditions for the Pythium to decide to feast on your crops, so don’t make it easy for them!
  • Keep your crops free of flies and mosquitoes, as they can carry the fungus.
  • You can use fungicides to prevent it. In Pevgrow we have a wide variety of them and we can recommend the most suitable one for your case. Ask us about it!

The Pythium fungus characteristics

🎯 How to fight it or treat it?

At Pevgrow we are concerned that this fungus may ruin your work for months and spoil your crop, so we bring you a varied selection of fungicides that will help you prevent the appearance of this undesirable fungus. Because you know…. you can’t be too careful!

The most appropriate fungicides for the treatment of Pythium are as follows:

  • Greendel Copper Fungicide for Fungus / Algae / Bacteria: a biological, preventive and curative product. With this natural product you will fight fungi, bacteria and algae.
  • Anti-mildew fungicide Flower (MIclobutanil): This product has a great benefit in the treatment of fungi. It is used for the preventive and curative control of numerous diseases caused by fungi such as powdery mildew, white spot, speckle, rust, oidiopsis, black-rot and anthracnose.

I forgot!. If you’re looking for a 100% natural alternative, you may be surprised to discover that even bees produce their own natural remedy for this fungus. It is propolis, a 100% natural bio-stimulator and fungicide made by them. Did you know that they actually secrete this substance to use as a kind of cement? They seal all the fissures of the hive, thus preventing the entry of any parasite or infection

You can find this natural substance in products such as Trabe Revihemp regenerador, which stimulates biochemical processes thanks to its composition rich in vitamins B, C and E. It will also improve the yield of your crops and stimulate your plant’s natural defenses by strengthening them against possible future attacks by fungi or bacteria.

In addition, we would not like to end this article without giving you one last recommendation for the prevention of Pythium. Renewing the mother plant from time to time is a very good option to fight against this fungus, as it can carry contaminated spores and also convert cuttings into carriers, which would ruin your new crop from the beginning..

Replacing it with one of the new plants after one or two uses would be ideal for a health cure. In this way, we will obtain young and strong mothers who will prevent the appearance of the feared fungus.

➕ Conclusion

In short, to talk about Pythium is to talk about a powerful and fast fungus that is worth being well informed and prepared to fight it before it ruins your entire marijuana crop

You can’t be too careful when trying to take care of your cannabis crops, but at Pevgrow we offer you all the information you need and all our most effective fungicide products against Pythium, to ensure that you can enjoy your weed without any surprises. We hope you found them useful!!?

If so, don’t hesitate to share this article with your friends and colleagues, it sure can help a lot of marijuana lovers and growers fight Pythium! We’d love to hear what you think of this post so don’t hesitate to leave us a comment ;).

Pythium can be eliminated and prevented by using appropriate fungicides ⚡. Keep your plants from spoiling ❤️ Before it's too late! ]]>