What to do if you have an outbreak of Fusarium fungus

Mention the word Fusarium to any experienced grower of cannabis plants and you will likely see them turn a whiter shade of pale and start to sweat.

Despite the fact that this fungus has been known about for many decades, and despite the fact it has been known to totally wipe out commercial crops of tomatoes, beans, asparagus and peas, nobody has found a cure or prevention for the fungus.

If your cannabis plants become infected with Fusarium, you have only one option, and that is to take drastic action.

When we say drastic, we’re politely telling you to destroy any affected plants the moment they show any signs of being infected.

So, what’s so deadly about Fusarium fungus.

One of the main reasons it is impossible to treat this fungus is because it works beneath the soil, not above ground.

It attacks the roots of the cannabis plant, to the point where the plant becomes unable to draw up moisture and nutrients from the soil, leading to a slow and painful death.

So, what are the signs, as you don’t want to destroy a healthy crop because some leaves are discolouring only because the plant is lacking a few nutrients?

The first thing to notice is the rapid decline of the plant’s health once it starts to display problems.

This fungus works fast!

Leaves can turn yellow and wilt. Growth can slow right down. Stems can swell and split, or decay and necrosis can be seen working its way up the stem. Is there any orange, pink or white fungus on the stem?

Check one plant before jumping to conclusions. Are the roots red in colour just under the topsoil. If you dissect the stem, is there a reddish tinge to the xylem vessel?

If you have convinced yourself that Fusarium is at work, then you have only one option available to you.

Remove and destroy all affected plants and watch your other plants very carefully.

If you are growing your plants outdoors, that soil won’t be usable again for several years.
To minimize the risk of an attack from Fusarium fungus, try these three things:

First, grow your plants in pots, so if one is affected, the fungus can be contained, and you don’t have to write off a section of land.

Make sure the soil is never too acidic and use dolomite lime if the pH level increases.
Add beneficial fungi, such as mycorrhizal. This helps plants absorb minerals while also helping to fight off other fungal pathogens.

We hope this is something you never experience, but if you do we’d love to know how you dealt with the situation in the comment section below.