Rose: Black mold categories: Flowers Ornamentals Rose Rose Diseases revision date: 2023-02-07 12:00 Biology Black mold primarily affects material used for propagation. The fungus grows on cut surfaces, such as at the contact points between rootstocks and scions and rootstocks and bud shields. This causes graft failures. A gray-white fungus growth is the first symptom […]
Rose: Black spot categories: Flowers Ornamentals Rose Rose Diseases revision date: 2023-02-07 12:00 Rose black spot on leavesPhoto by: R.S. Byther Biology Black spot is a very common fungal infection of the leaves and canes of roses. Round black leaf spots (sometimes with fringed or feathery edges) may be accompanied by leaf yellowing and leaf […]
Rose: Botrytis bud and twig blight categories: Flowers Ornamentals Rose Rose Diseases revision date: 2023-02-07 12:00 Botrytis on rose canesPhoto by: R.S. Byther Biology Botrytis can infect stems and flowers, including stubs left from pruning or flower removal. Infected tissues are usually covered with a fuzzy, gray-brown growth. Infected flower buds may not open, and […]
Rose: Brand canker categories: Flowers Ornamentals Rose Rose Diseases revision date: 2023-02-07 12:00 Rose brand cankerPhoto by: R.S. Byther Biology Brand canker is a fungal disease that often infects plants in the winter, especially when winter protection of roses keeps the canes moist. Initial symptoms of infection are small dark red spots on the canes. […]
Rose: Bullheading (cold damage) categories: Flowers Ornamentals Rose Rose Diseases revision date: 2023-02-07 12:00 Rose bullheadPhoto by: R.S. Byther Biology Bullheads are the most prevalent when temperatures dip to 53-59 degrees Fahrenheit during early flower development. Low temperatures appear to alter metabolic activity, which results in the abnormal appearance of buds and resulting flowers. Flower […]
Rose: Common canker categories: Flowers Ornamentals Rose Rose Diseases revision date: 2023-02-07 12:00 Rose common cankerPhoto by: R.S. Byther Biology Common canker is a fungal disease that infects plants through long stubs left by improper pruning or through other wound sites. Small yellow or reddish spots appear on canes and gradually enlarge. Later, the centers […]
Rose: Crown gall categories: Flowers Ornamentals Rose Rose Diseases revision date: 2023-02-07 12:00 Crown gall on crown of rose.Photo by: R.S. Byther Biology Crown gall on roses usually occurs at or just beneath the soil surface. It may also be found on stems and roots. Young galls appear as a soft thickening in stems or […]
Rose: Downy mildew categories: Flowers Ornamentals Rose Rose Diseases revision date: 2023-02-07 12:00 Downy mildew on rosePhoto by: R.S. Byther Biology Downy mildew can affect leaves, stems, flower stems, and flower parts. The infection is usually found only on young growth. On leaves, symptoms include purplish or brown spots, usually between veins, and yellow leaves […]
Rose: Powdery mildew categories: Flowers Ornamentals Rose Rose Diseases revision date: 2023-02-07 12:00 Powdery mildew on rosePhoto by: R.S. Byther Biology Powdery mildew is a fungus attacking leaves, stems, and flower parts. Usually young growth is most severely affected. Reddish, blister-like areas on the upper side of leaves are followed by powdery white growth, which […]
Rose: Rust categories: Flowers Ornamentals Rose Rose Diseases revision date: 2023-02-07 12:00 Rust on rose leavesPhoto by: R.S. Byther Biology Rust usually is first noticed as clumps or pustules of red to orange powder on the lower surfaces of leaves. The upper surface may also show yellow, orange, or brown spots, corresponding to the location […]
Rose: Leafcutting bees categories: Flowers Ornamentals Rose Rose Insects revision date: 2023-02-07 12:00 Leafcutting bee damagePhoto by: K. Grey Biology Leafcutting bees remove smooth circular or semi-circular notches from the edges of leaves of roses and other plants. The leaf pieces are used by the bees to create protective cells for raising their young. Leafcutting […]
Rose: Leafrollers categories: Flowers Ornamentals Rose Rose Insects revision date: 2023-04-04 12:00 Rose leafroller on leafPhoto by: A.L. Antonelli Biology Several different caterpillars roll leaves on roses. Among these are the obliquebanded leafroller, which is green with a dark head, and the orange tortrix, which is tan to greenish with a tan head. Leafrollers are […]
Rose: Redhumped caterpillar categories: Flowers Ornamentals Rose Rose Insects revision date: 2023-02-07 12:00 Redhumped caterpillarsPhoto by: A.L. Antonelli Biology The redhumped caterpillar is the larvae of a 1″ gray-brown moth. The mature larvae are yellow with a red head and hump, and have orange, black, and white lengthwise stripes. The body of the caterpillar also […]
Rose: Root weevils categories: Flowers Ornamentals Rose Rose Insects revision date: 2023-04-04 12:00 Adult root weevil damagePhoto by: E.P. Breakey Biology Several species of weevils feed on roses. Adult weevils feed on the leaves, leaving small ragged notches along the edges. They may also feed on the flowers. They are wingless gray, brownish, or black […]
Rose: Rose aphids categories: Flowers Ornamentals Rose Rose Insects revision date: 2023-04-04 12:00 Aphid colonyPhoto by: R.S. Byther Biology Rose aphids are small, soft, pinkish or green insects found on the succulent new growth, including buds and stems. White cast skins can also be present. Heavy aphid feeding can reduce the quantity and quality of […]
Rose: Rose galls categories: Flowers Ornamentals Rose Rose Insects revision date: 2023-02-07 12:00 Mossy rose gall on stem caused by an insectPhoto by: R.S. Byther Biology Insects can cause two types of rose galls: spiny rose gall and mossy rose gall. The spiny rose gall is caused by tiny cynipid wasps. They produce small hard […]
Rose: Rose leafhopper categories: Flowers Ornamentals Rose Rose Insects revision date: 2023-02-07 12:00 Rose leafhopper damagePhoto by: A.L. Antonelli Biology Rose leafhoppers are small, active, whitish-green insects which hop when disturbed. The nymphs (immature) are white with red eyes. Rose leafhoppers feed on the leaves, causing white or pale blotches that resemble, but are larger […]
Rose: Rose midge categories: Flowers Ornamentals Rose Rose Insects revision date: 2023-02-07 12:00 Photo by: A.L. Antonelli Biology The rose midge is a tiny yellow-brown or reddish fly that lays its eggs in newly developing bud and shoot tips. The hatching maggots feed on the growing tips. New buds and shoots are deformed and killed […]
Rose: Roseslug categories: Flowers Ornamentals Petunia Insects Rose Rose Insects revision date: 2023-04-04 12:00 Rose slug and damagePhoto by: A.L. Antonelli Biology Rose slugs are small yellow-green larvae (about 1/4″ long) that skeletonize the upper leaf surface. Signs of feeding include dry brown blotches, where all of the leaf except the veins and the lowest […]
Rose: Spider mites categories: Flowers Ornamentals Rose Rose Insects revision date: 2023-02-07 12:00 Spider mite damage on rosePhoto by: R.S. Byther Biology Spider mites are tiny, eight-legged, and yellowish to brown in color. They cause mild to severe stippling (little specks or dots) on leaves. Usually yellowish to bronze in color, stippling can, in severe […]