Lime (linden) powdery mildew

Symptoms

A thin, white to greyish powdery coating develops on the upper (and sometimes lower) surface of the heart-shaped leaves, often starting as discrete circular patches on young foliage and shoot tips in mid- to late summer. Affected leaves may be slightly distorted, cupped or stunted, and a faint chlorotic mottling can show through the fungal film; heavily colonised young leaves can yellow and drop early. By late season tiny pinhead-sized fruiting bodies (cleistothecia) appear as amber-to-black specks scattered in the white mat. Mature trees usually tolerate the infection with cosmetic leaf coating, while nursery stock, suckers and water-shoots are the most heavily affected.

Plants affected

• small-leaved lime

Common questions

How do I recognise Lime (linden) powdery mildew on small-leaved lime?

A thin, white to greyish powdery coating develops on the upper (and sometimes lower) surface of the heart-shaped leaves, often starting as discrete circular patches on young foliage and shoot tips in mid- to late summer. Affected leaves may be slightly distorted, cupped or stunted, and a faint chlorotic mottling can show through the fungal film; heavily colonised young leaves can yellow and drop early.

Do I have to report Lime (linden) powdery mildew?

No. Lime (linden) powdery mildew is not a notifiable organism, so there is nothing to report to an authority. Treat it as a normal garden problem.

How is Lime (linden) powdery mildew 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.