Mint Rust
Answered by: Richters Staff
Question from: Erik Nielsen
Posted: Before April 1998
Do you know of any cure or growing tips against mint rust?


Rust (Puccinia menthae) is a fungus that attacks mints (Mentha) and other members of the mint family such as bergamot, germander, mountain-mint and yerba buena. It is a serious problem for mint farmers in the United States because it reduces oil yields by as much as 40% and even kills some plants.

It appears in early summer as light yellow or brown raised spots on deformed stems, leafstalks and on the veins of leaves. In late summer or fall it is golden to chocolate brown in colour.

Overcrowded plants are particularly susceptible to rust. Mints are such prolific growers that they can form dense, tangled masses in just two or three years.

To reduce the severity of rust damage, remove dead foliage in fall. This will reduce the chance of spores overwintering. In early spring thin plants by rooting up rhizomes and roots. If symptoms reappear dust with sulfur and harvest early before rust damage becomes severe.

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