Optimal Conditions
Following a wet summer
Signature
Coloured spots on the leaves, typically a rust-like colour
Prevention
Regularly fertilise with seaweed extract that contains plenty of potassium, sulphur, and other trace elements (including copper) that boost the plants’ immune systems. However, don’t overfeed with nitrogen, as the young, soft plant growth is more likely to host the spores.
Coping
For mild cases of rust, remove damaged parts of the affected plant and burn these, or dispose of them in a sealed plastic bag. Don’t ever compost them, as the spores may not be killed.
Eradicating
You can make an organic fungicide using 100 parts water, 10 parts bicarbonate of soda (baking soda), 1 part oil and 1 part liquid detergent. The bicarbonate is the active ingredient that helps to kill the fungal spores, while the oil and detergent help to fix and spread the mix over the leaf foliage respectively.
