Go to Mizzou without going to Mizzou
Instant access
Soil Testing
and Plant Diagnostic Services
MU affiliations
Other alliances
Plant Diagnostic Clinic
573-882-3019
Irregular brown areas on fading flowers and leaves occur in wet springs. May be covered with gray mold in wet weather. Apply fungicide just before, during and after bloom, especially during wet periods. Use iprodione or thiophanate-methyl.
Dogwood
anthracnose is a lethal disease of Pacific dogwoods, flowering dogwoods and some
varieties of Kousa dog woods. It is not established in Missouri to date, but be
alert for symptoms: leaf spot, blotches and shoot dieback that are obvious in
early spring to mid-summer, twig and branch die back occurring throughout the
season, and proliferation of succulent shoots on the lower stem. Avoid bringing
in planting stock from Eastern states. If you notice symptoms, please send samples
to the Extension Plant Disease Clinic.
Margins
of leaves turn brown. Most likely to occur when trees are planted in full sun,
following transplant, or when nutrient deficient. Dogwoods may be nutrient deficient
in soils with pH above 7. See leaf scorch in General Problems table. Avoid planting
dogwoods on exposed sites.
Leaves appear gray or white powdery on the surface. Young leaves may be distorted. Seriously affected leaves may brown and die. Powdery mildews have become serious in some areas of the South, but serious levels have not been seen in Missouri. If you think you have seriously damaging levels of this disease, please submit a sample to the Extension Plant Disease Clinic. Myclobutanil, thiophanate-methyl, thiophanate-methyl plus mancozeb, or triadimefon may be used if serious.
Common in wet seasons. Spots of various sizes, shapes and colors, often with dark-purple to brown borders. Apply fungicide once a month, starting in April when flower buds are in the cup stage and continuing until the flower buds for the following year are formed in late summer. Use copper fungicides (see label), quaternary ammonium compounds, mancozeb or thiophanate-methyl.
Updated 3/31/05
On this page
Related page
On this site
Contact
