downy mildew

noun

1

: any of various parasitic lower fungi (family Peronosporaceae) that produce whitish masses of sporangiophores or conidiophores on the undersurface of the leaves of the host

2

: a plant disease caused by a downy mildew

Examples of downy mildew in a Sentence

Recent Examples on the Web

New Guinea impatiens produce larger flowers on larger plants than traditional impatiens and have better resistance to downy mildew. —Kim Toscano, Southern Living, 2 May 2026

Unlike black spot, downy mildew often starts at the top of the plant. —Rita Perwich, San Diego Union-Tribune, 2 May 2026

Another common spinach ailment is downy mildew, which causes yellow or light-green spots on the upper surface of the leaves and a white fungus on the lower surface. —Michelle Mastro, Martha Stewart, 29 Apr. 2026

Gardeners will be glad to know plants are resistant to impatiens downy mildew. —Dawn Pettinelli, Hartford Courant, 12 Jan. 2024

Minor diseases like powdery mildew or nuisance pests like aphids are less of a concern, but more substantial diseases like downy mildew and pests like allium leaf miner are best managed with prevention. —Miri Talabac, Baltimore Sun, 7 Sep. 2023

Word History

First Known Use

1886, in the meaning defined at sense 1

Rhymes for downy mildew

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