Sooty Mold Of Conifers And Hardwoods
The presence of a black, soot-like fungus, frequently appearing as a thin crust over the surface of leaves, is the best indicator of this problem (Fig. 1). However, some species of sooty molds grow as a thick, spongy ... [... more]
Virginia Tech Extension |
Powdery Mildew Of Ornamental Plants
The prolific growth and sporulation of the fungus on the surface of leaves and other plant parts give the affected tissue a talcum powder-like appearance, hence the name "powdery mildew" (Fig. 1). The new growth of ... [... more]
Virginia Tech Extension |
Fire Blight Of Ornamentals
Blossoms, young fruits, small twigs, leaves and water sprouts are susceptible to infection. Blossoms and leaves wilt suddenly, turn dark brown to black, shrivel, and die, but usually remain attached to the plant. ... [... more]
Virginia Tech Extension |
Verticillium Wilt Of Shade Trees
The fact that Verticillium species are able to attack both herbaceous and woody plants complicates control. Verticillium-susceptible weeds, such as lamb's quarters, amaranth (pigweed), nightshade (horse nettle), and ... [... more]
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Foliar Diseases Of Dogwood
Few cultivars of flowering dogwood have resistance to Discula anthracnose. Breeding programs to identify sources of resistance are ongoing. The 'Spring Grove' and 'Cherokee Sunset' cultivars of flowering dogwood have ... [... more]
Virginia Tech Extension |
Powdery Mildew-Resistant Woody Ornamentals
Powdery mildew is a common fungal disease of many ornamental plant species. Although plants are not often killed by the disease, they may become unsightly when heavy fungal growth develops on leaves and flowers. ... [... more]
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Anthracnose - A Fungal Disease Of Shade Trees
On sycamore, leaves and growing tips of the twigs may die as they emerge from the bud. This damage is often confused with late frost injury. Sudden browning and killing of single leaves or leaf clusters may occur as ... [... more]
Virginia Tech Extension |
Crown Gall Of Woody Ornamentals
A biological control agent consisting of certain strains of the related bacterium Agrobacterium radiobacter has been shown to be very effective in reducing the incidence of crown gall on susceptible plants. ... [... more]
Virginia Tech Extension |
A Guide To Successful Pruning: Pruning Basics And Tools
Use hand pruners to cut stems up to 3/4 inches in diameter. Two types of pruners are available: bypass and anvil. Bypass pruners have sharpened, curved, scissors-type blades that overlap. Anvil pruners have straight ... [... more]
Virginia Tech Extension |
Eriophyid Mites On Pine
The observable damage varies from tree to tree and can vary within a single planting. The most common symptom is sickly yellow needles with browned tips, although some needles may have a blotched appearance. Mites ... [... more]
Virginia Tech Extension |
Fertilizing Trees And Shrubs
Complete fertilizers contain the three nutrients plants need in the largest amount for optimum growth - nitrogen (N), phosphorus (P), and potassium (K). A fertilizer labeled "10-10-10" contains 10% nitrogen, 10% ... [... more]
Virginia Tech Extension |
Fertilizing Landscape Trees And Shrubs
Fertilizer should be applied when plants need it, when it will be most effective, and when plants can readily take it up. Late summer and early fall fertilization may stimulate new growth that is not winter hardy, ... [... more]
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