Rose Black Spot
Small, round spots, ranging in size from 1/16" to 1/2" in diameter, appear on the upper sides of leaves. Leaf tissue adjacent to the spot turns yellow. Whole leaves eventually turn yellow and fall prematurely. Black ... [... 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 |
Juniper Tip Blights
In Virginia, juniper tip blight is caused by one of two different fungi, Phomopsis juniperovora or Kabatina juniperi. Symptoms of the two diseases are identical; however, some aspects of their control differ. ... [... more]
Virginia Tech Extension |
Entomosporium Leaf Spot Of Photinia
Leaf spots on photinia first appear as minute, slightly raised dots on either surface of the leaf. Older spots have a slightly depressed center with raised margins (Fig. 1). On the juvenile, reddish colored foliage ... [... 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]
Virginia Tech Extension |
Phytophthora Root Rot Of Rhododendron And Azalea
Disease development is favored by high soil moisture and soil temperatures of 80°F and above. Infected plants growing on sandy soils are generally not as seriously affected by the disease, whereas those growing on ... [... more]
Virginia Tech Extension |
Azalea Leaf And Flower Gall
Exobasidium vaccinii causes leaves and flowers to become swollen, curled, waxy and fleshy (Fig. 1). The swollen plant tissues or "galls" are made up of abnormal plant tissue. Infected leaf tissue is usually pale ... [... 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 |
Black Root Rot Of Japanese Holly
Black root rot has been reported on many herbaceous ornamentals and several important vegetable and field crops, including bean, tobacco, and peanut. Thielaviopsis basicola has also caused the failure of scion ... [... 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 |
Boxwood Leafminer
Damage is caused by yellow-orange larvae that feed between the upper and lower layers of leaves. Infested leaves appear blistered on the underside and are often discolored. As the larvae matures and the damage ... [... more]
Virginia Tech Extension |
