powdery mildew

noun

1

: an ascomycetous fungus (family Erysiphaceae) producing abundant powdery conidia on the host

2

: a plant disease caused by a powdery mildew

Examples of powdery mildew in a Sentence

Recent Examples on the Web

Prune bee balm, phlox, and peonies in fall to prevent diseases like powdery mildew; do not compost diseased foliage. — Lauren Landers, Better Homes & Gardens, 28 Sep. 2026

Do cut back plants with diseased foliage (peonies with powdery mildew, for example) to prevent reinfection next year. — Pam Rosendal, Denver Post, 27 Sep. 2026

Reduced airflow can make the plant susceptible to diseases like powdery mildew and dieback disease, as well as pests. — Karen Brewer Grossman, Southern Living, 14 Sep. 2026

Wet leaves encourage diseases such as black spot and powdery mildew. — Michele Laufik, Martha Stewart, 25 Aug. 2026

Word History

First Known Use

1889, in the meaning defined at sense 1

Rhymes for powdery mildew

• accrue
• ado
• ainu
• aircrew
• airscrew
• anew
• askew
• baboo
• babu
• bamboo
• beaucoup
• bijou

Kids Definition

powdery mildew

noun

: a fungus that is a parasite and produces a large number of powdery spores on the host

also : a plant disease caused by such a fungus