flax rust is a wet spring thang. we had a wet spring and we got the thang.
summer should cook it off. it overwinters on the old duff. my guess is that once the burning begins and the old duff becomes charcoal, the problem will go away.

if its an individual garden plant, u need a different mulch. and clean up the place.

just a note, i just saw this spring a daddy longlegs 1/2 covered w/ rust along with everything else living under a osb board i had laying on the ground over winter. by the time i ran and got my camera, i couldnt find the poor girl.

froggy

Oh poor Daddy Longlegs!
Yep,, we had a good few weeks of cool, wet weather, but no these are not individual garden plants that were affected but are in my prairie area. I cannot burn here because this area (60x16) runs along the side of my house.

You could try spraying with garden sulphur.