sage rust

Symptoms

Yellow-orange pustules on the underside of leaves with corresponding chlorotic spots above, premature leaf drop, reduced harvest of aromatic leaves.

Plants affected

• common sage

Easily confused with

• overwatering / waterlogging

  How to tell them apart: Turn a yellowing leaf over: Puccinia salviae (sage rust) shows discrete raised yellow-orange to rusty-brown powdery pustules on the leaf UNDERSIDE, each matched by a bright chlorotic spot directly above; rub a finger across them and orange spores come off. Overwatering (abiotic waterlogging) gives NO pustules or spores at all — instead the whole lower, oldest leaves yellow evenly and go limp, the stem base near the soil turns soft, brown and mushy, roots smell sour and rot, and the symptom pattern follows wet, poorly drained soil rather than spreading leaf-to-leaf. Rust spreads upward and to neighbouring plants by wind; overwatering stays with the soggiest pots and improves when the soil dries out.

Common questions

How do I recognise sage rust on common sage?

Yellow-orange pustules on the underside of leaves with corresponding chlorotic spots above, premature leaf drop, reduced harvest of aromatic leaves.

Do I have to report sage rust?

No. sage rust is not a notifiable organism, so there is nothing to report to an authority. Treat it as a normal garden problem.

How is sage rust treated?

Mainly with biological and cultural measures — removing affected material, changing the conditions that favour it, and treating with agents approved in your country. The exact steps and their timing depend on the plant, the season and where you live: Dr. Phyto works them out in a free diagnosis.