One of my potted mints has been looking a bit sick for a while.
While the rest of my mints are happily celebrating Spring and putting on heaps of new growth, this one has been looking sadder and sadder by the minute. On close examination you can see orange dots all over many of its stems. They look like this:
I had a bit of an explore on google and diagnosed mint rust. Now there are a couple of recommended treatments for mint rust. Apparently you could remove the plant from the pot and wash it, including roots, in a mixture of bleach and detergent. But I had no bleach and besides the other suggested option involved setting stuff alight, so naturally that’s the course of action I took.
I cut the plant to ground level. I put foil around the exposed plastic of the pot it is planted in.
The foil protects the plastic for the heat of the fire. You can employ a similar technique when sowing seeds, which require smoke to germinate (many Australian native plants do), in plastic seed trays. I then covered the top of the pot with scrunched up newspaper and topped it with some chicken wire to stop flaming paper from blowing around the garden.
Then I set it alight.
The idea behind this is that the heat from the fire kills the rust spores but the mint roots are protected by the potting mix and survive to grow again.
Whether or not it works remains to be seen. A few things could have gone wrong. I may not have killed all the rust spores. The fire may have been so hot it killed the mint roots. The plant may simply not want to grow for someone who sets it on fire…
I removed most of the ash after this photo was taken. I will water the pot tomorrow, but not too much as the rust likes damp conditions. Hopefully it wont take too long before the plant grows back, I do have other healthy plants but I also eat a lot of mint.