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Damping Off in Cannabis Seedling: Causes, Cure, Prevention

The damping off disease is actually a response to an illness which may happen to your Marijuana seedling due to an intrusion on either the roots, seed or seedlings, from a fungi found in your soil. Unfortunately if this has happened to you, there is a low chance that you will be able to save it, however let’s dive into this subject further and see what may have caused your plant to damp off, how to cure it and how to avoid this from happened in future.

Cannabis Damping off Disease Process

When there are optimal conditions for the development of fungus, your plant will be affected at the bottom of the stem and get weakened by having its supply of fluids cut. When this happens, it becomes impossible for nutrients to reach the top side of your seedling, and in doing so, the stem becomes mushy, weak and die.

damping off cannabis seedling

Damping off Causes: How Did it Happen?

The best environment for a fungus to survive and thrive is in a warm and moist soil with plenty of nitrogen. This is why it is know that you are not supposed to give your plant nutrients in its first two weeks of her life, as it can help the growth of fungi and other unwanted pathogens which will impede the succesful growth of your Cannabis seedling.

A fungus can also already exist in the soil which you are using to germinate your Cannabis seeds, especially when you haven’t sterilized it before hand. Make sure that you always sterilize or at the very least ‘clean’ growing pots, especially the pots which you have used before. Using water and bleach for this purpose is good enough.

There are other factors as well which can contribute to this deadly disease of your seedlings, so make sure you keep an eye on bad drainage, over-watering, poor air circulation and excess humidity. Here is an article with a twist on maximizing the success rate for Marijuana seed germination.

Damping off Symptoms

The stem has lesions between nodes with brownish red cankers, it suffers discoloration near its base and atrophy appears in stalk and lower leaves. The stem narrows at soil level, is browning, gets softer, the plant falls over, wilting (loss of rigidity) happens and all these eventually leading to the plant’s death.

damping off seedling symptoms

Damping off Cure

There is a good chance that you won’t be able to save your seedling in most cases, however if the plant is mature enough, there is still hope! Start by gently removing the affects parts, pour a capful of Hydrogen Peroxide in a glass of water (make sure your solution is diluted enough) and apply it over the wounds. Besides this, you can also try spraying the affected stems with copper fungicide, sesame oil, coriander or clove oil.

Damping off Prevention

One of the first things you should keep in mind and apply is to maintain optimal air circulation, as this is very important in preventing damping off.

Most gardeners avoid damping off by using a classic homemade solution made from combining chamomile tea and garlic. There can also be used anti-fungal treatments such as Copper Oxychloride for spraying and drenching the soil, controlling the resistant fungus to other fungicides as well.


Now you are aware of pretty much everything you need to know and keep in mind the next time you successfully sprout your Marijuana seeds. Damping off disease can be easily avoided if you realize that during this stage your plant’s life, she needs a meticulous attention to detail in order to grow strong roots and a great healthy foundation.

Let us know in the comments below about your experience or perhaps advice on the topic of Cannabis seedlings damping off.

2 thoughts on “Damping Off in Cannabis Seedling: Causes, Cure, Prevention”

  1. Thank you.
    This article is the first I’ve found giving no nonsense info on damping off (and I’ve a lot of weed info!)
    I’m an old man now but have always enjoyed growing plants – in younger days mainly fruit & veg in the garden. In later years mostly houseplants in pots. I live in Spain now and for the last few years I’ve grown various strains of cannabis, in pots, out on my South facing balcony.
    Accepting that I’m a stubborn and contrary old man – I’ve sought advice on some of the problems I’ve had in growing “The God Plant” usually from Nirvana, my affordable (just) seed supplier.
    I’ve reluctantly concluded that they’re not really interested in their customers as their “advice” is usually ambiguous and not helpful – they seem to only be interested in sales.
    So – it’s very refreshing to come across your site. I’ll be back.
    Thanks again.

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