Verbena Diseases

Disease	Symptoms	Pathogen/Cause	Management
Botrytis Blight	Tan spots develop on leaves. Established plants rot at the crown. Infected tissue is covered with dusty gray fungal growth.	Botrytis cinerea	Maintain low humidity by spacing plants and venting to improve air circulation. Remove dead and dying flowers and leaves. To protect healthy plants, apply fenhexamid or fludioxonil.
Powdery Mildew	White fungal growth forms on the upper surface of leaves and may form on flower petals.	Erysiphe cichoracearum	Apply Ampelomyces, trifloxystrobin, or kresoxim methyl to protect plants
Pythium Root Rot	Roots are dark brown. Plants are wilted and yellowed.	Pythium spp.	Do not over water plants. Pot in pasteurized media. Keep hose ends off the ground. To protect healthy plants, apply mefenoxam.

COMMON NAME	TRADE NAME
Ampelomyces quisqualis	AQ10 (biological control agent)
fenhexamid	Decree
fludioxonil	Medallion
flutolanil	Contrast
triflumizole	Terraguard
kresoxim methyl	Cygnus
mefenoxam	Subdue Maxx