University of Vermont Extension System
Department of Plant and Soil Science

Powdery Mildew on Phlox and Monarda:                 COH 40
Control Studies, References

Dr. Leonard P. Perry, Extension Professor

Organic Controls Research (Vermont)

1991-93 in Vermont, 'White Admiral' Phlox, replicated

4 Baking soda, 0.5% (1.5Tbsp/gal water, weekly)

4 Sunspray Horticultural Oil (3Tbsp/gal water, every 2 weeks)

4 Both combined (every 2 weeks)

t Antidessicants (Wilt-Pruf, ForEverGreen)

t Mulch, 2" (bark, marble chips)

t Spacing (1 or 2 ft)

1999, ‘Mr. Fuji’ Phlox, replicated 4 WiltPruf, followed by Remedy t Neem 2000-2001, ‘Snow White’ Bee Balm (Monarda didyma) 4 WiltPruf and SunSpray in 2000, Sunspray and Remedy (potassium bicarbonate) in 2001 t Neem in 2000 (not used in 2001), Sulfur (not used in 2000) and baking soda in 2001

Chemical Controls Research

3 Significant control by horticultural oil at 2% and 3% rates, and at 2 and 3 week intervals

3 Often Funginex provided the least control

3 Bayleton control was intermediate

Some Useful References

Return to Perry's Perennial Pages

Issued in furtherance of Cooperative Extension work, Acts of May 8 and June 30, 1914, in cooperation with the United States Department of Agriculture. Lawrence Forcier, Director, UVM Extension System, Burlington, Vermont. University of Vermont Extension System and U.S. Department of Agriculture cooperating, offer education and employment to everyone, without regard to race, color, national origin, sex, religion, age, disability, political beliefs, and marital or familial status.

Last reviewed 11/15/01