In this review of literature published from 1999 to 2016, 99 products representing 57 active ingredients were screened in greenhouse and field experiments against several species causing powdery mildew on ornamentals. These pathogens included: Erysiphe azaleae, Erysiphe knautiae, Erysiphe lagerstroemia, Erysiphe lonicerae var. lonicerae, Erysiphe monardae, Erysiphe polygoni, Erysiphe pulchra, Golovinomyces cichoracearum, Oidium spp., Podosphaera pannosa, and Podosphaera xanthii. The established products like 3336, Banner MAXX, Compass, Eagle, Heritage, Insignia, Pageant, Pipron, and Terraguard generally provided consistent efficacy. Although there were insufficient data for definitive conclusions, several new products included in the IR-4 efficacy experiments looked promising. These include IKI-309, Mural, NF-149, and Orkestra. Other products in this research – F9110, Mettle, Milstop, Regalia and ZeroTol – provided generally inconsistent results. Milsana was ineffective in IR-4-sponsered research. Other new products that looked promising include Picatina and other pydiflumetofen products (Picatina Flora and Picatina Gold). Further research is needed to obtain additional efficacy data to recommend actions to register or amend labels for these pests.