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

Space plants 12 inches apart and water at the base to prevent powdery mildew. — Karen Brewer Grossman, Southern Living, 29 June 2026

For best results, water plants slowly and deeply and direct your hose at the soil line so plant leaves stay dry and are less likely to develop powdery mildew and other problems. — Lauren Landers, Better Homes & Gardens, 28 June 2026

Trellising plants keeps them lifted off the ground, reducing pest infestations and improving airflow to reduce the risk of powdery mildew. — Madeline Buiano, Martha Stewart, 27 June 2026

Excessive watering, especially late in the day from overhead sprinklers, can cause fungal diseases like powdery mildew. — Mary Marlowe Leverette, The Spruce, 17 June 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