root rot in cannabis plant

How to prevent root rot in cannabis plants

Root rot is one of the main problems in the cultivation of medicinal cannabis. It directly affects the cultivation, making the plant sick and affecting the production and the yield, to the point that it might cause the total loss of the crop.

Many growers are constantly looking for chemical solutions to a problem that can be solved in a much more sustainable and healthy way for the plant and the consumer.

Root rot disease can be caused by different fungi, yet they all have a common characteristic: they attack the most important part of the plant: the roots.

“These fungi, such as Fusarium, Phytophthora or Pythium, do not need host plants to survive, so they can remain and live for months or even years in culture media such as soil or dead plant matter, until they find an ideal host to colonize”, says María José Ferrando, Product Manager at Projar.

“For this development of fungi to occur, there are some very specific and quite common factors that must occur in most cases, such as a warm soil temperature (15º-30º), an excess of humidity, little drainage and fertilizations rich in nitrogen.”add Ferrando.

In addition, once infected, the plant takes several days to show signs of disease. It could take even weeks before first symptoms become visible in the aerial part, such as a slow development and a slight chlorosis in the leaves: the plant can take up to one week to die. For this reason, it’s highly important to anticipate the conditions and prevent the spread of the pathogen.

There are many chemical remedies that artificially strengthen the roots, affecting the product and its use. But there are also simple tricks that help solving such problems in a much more sustainable way.

The most important part of a plant is its roots, since these are the engine of the plant: they transport water and minerals that they absorb from the soil and store the nutrients that are elaborated during photosynthesis, in addition to their function of anchorage.

medicinal cannabis production

In order for plants to develop roots as healthy as possible, it is critical to choose a good growing medium and opt for good techniques that guarantee success. Thus, it is very important to choose a good substrate that provides a good drainage and optimum root aeration, so to avoid waterlogging that damages the roots.

In addition, it is essential to choose pots that help solve these problems and become allies of the crop.

Pots fundamental characteristics

Growing containers with supporting legs: As the base is elevated, the root part will never be in contact with the soil and we will prevent it from becoming infected with any pathogen that may be in it.

Pot with a mesh base: These guarantee a very good drainage. In the event of an irrigation excess, the water does not accumulate in the root ball, thus avoiding potential problems. In addition, this raised grid of the soil will allow continuous air circulation, which will promote root oxygenation at all times: this helps the roots to colonize the entire volume of substrate.

Square pot with grooves on the inner sides, which favors root growth directed downwards and expanded throughout the substrate, thus preventing the roots from growing in a circular manner and not allowing the secondary roots and capillaries to develop properly.


At Projar we have developed pots, lifts and cultivation accessories specifically designed for the production of cannabis. “We have worked for years hand in hand with our clients to offer them the best tools that allow them to avoid cultivation problems and maximize the result of their efforts. Our solutions are the result of customization and active listening to the needs of our customer.” María José points out.

Projar offers the professional cannabis grower the range of Growpot and Growpot Plus pots, with 7 and 10 L capacity. “Our range of pots ensures adequate drainage and the necessary aeration for the cannabis plant so that puddles do not occur that can cause root suffocation and root rot”. These solutions are available at

Subscribe to the Projar family and keep up to date with our news