Wet Feet (physiological): Elaeagnus (Russian olive) is a hardy woody shrub with few disease problems. It is, however, vulnerable to excessively wet soils. Elaeagnus should be planted on well-drained sites and not in low spots or in soils that retain water.
Leaf Spots (fungi – Cercospora carii, Cercospora elaeagni, Phyllosticta argyrea, Septoria argyrea): Spots may vary in size, color and shape. These fungi are rarely severe enough to warrant control measures. Prune out heavily infected foliage if it becomes unsightly.
Southern Blight (fungus – Sclerotium rolfsii): Southern blight primarily attacks elaeagnus in the seedling stage. Plants usually wilt as the stems rot at or below the soil line. A white, cottony mold may be evident on the lower stems near the ground line. Brown fruiting bodies (sclerotia) are often scattered through the cottony fungus growing on the stem. This disease does not normally attack older plants.
Cotton Root Rot (fungus -Phymatotrichum omnivorum): As with most woody ornamentals, elaeagnus will die quite rapidly when infected with the cotton root rot fungus. Plants will die so rapidly that leaves are not shed but are retained on the plant. Cutting the base of the plant with a knife soon after it dies will show that the base of the plant and the roots died before the upper part of the plant. The woody portion of the crown will be darker than in the branches and stems. No controls are known.