Rose: Black mold Categories: Flowers Ornamentals Rose Rose Diseases Last review date: 2025-07-28 10:52 Last edit date: 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 […]
Rose: Black spot Categories: Flowers Ornamentals Rose Rose Diseases Last review date: 2026-08-28 02:29 Last edit date: Rose black spot on leaves Photo 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 […]
Rose: Botrytis bud and twig blight Categories: Flowers Ornamentals Rose Rose Diseases Last review date: 2026-08-28 02:15 Last edit date: Botrytis on rose canes Photo 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 […]
Rose: Brand canker Categories: Flowers Ornamentals Rose Rose Diseases Last review date: 2025-07-28 10:56 Last edit date: Rose brand canker Photo 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 […]
Rose: Bullheading (cold damage) Categories: Flowers Ornamentals Rose Rose Diseases Last review date: 2025-07-28 10:58 Last edit date: Rose bullhead Photo 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 […]
Rose: Common canker Categories: Flowers Ornamentals Rose Rose Diseases Last review date: 2025-07-28 10:59 Last edit date: Rose common canker Photo 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 […]
Rose: Crown gall Categories: Flowers Ornamentals Rose Rose Diseases Last review date: 2025-07-28 11:00 Last edit date: 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 […]
Rose: Downy mildew Categories: Flowers Ornamentals Rose Rose Diseases Last review date: 2026-08-28 01:39 Last edit date: Downy mildew on rose Photo 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 […]
Rose: Powdery mildew Categories: Flowers Ornamentals Rose Rose Diseases Last review date: 2026-08-28 01:56 Last edit date: Powdery mildew on rose Photo 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 […]
Rose: Rust Categories: Flowers Ornamentals Rose Rose Diseases Last review date: 2025-07-28 11:06 Last edit date: Rust on rose leaves Photo 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 […]
Rose: Leafcutting bees Categories: Flowers Ornamentals Rose Rose Insects Last review date: 2025-07-28 11:14 Last edit date: Leafcutting bee damage Photo 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 […]
Rose: Leafrollers Categories: Flowers Ornamentals Rose Rose Insects Last review date: 2026-09-29 06:57 Last edit date: Rose leafroller on leaf Photo 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 […]
Rose: Redhumped caterpillar Categories: Flowers Ornamentals Rose Rose Insects Last review date: 2025-07-28 11:20 Last edit date: Redhumped caterpillars Photo 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 […]
Rose: Root weevils Categories: Flowers Ornamentals Rose Rose Insects Last review date: 2026-09-29 06:57 Last edit date: Adult root weevil damage Photo 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 […]
Rose: Rose aphids Categories: Flowers Ornamentals Rose Rose Insects Last review date: 2026-09-29 06:57 Last edit date: Aphid colony Photo 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 […]
Rose: Rose galls Categories: Flowers Ornamentals Rose Rose Insects Last review date: 2025-07-28 11:24 Last edit date: Mossy rose gall on stem caused by an insect Photo 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 […]
Rose: Rose leafhopper Categories: Flowers Ornamentals Rose Rose Insects Last review date: 2025-07-28 11:26 Last edit date: Rose leafhopper damage Photo 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 […]
Rose: Rose midge Categories: Flowers Ornamentals Rose Rose Insects Last review date: 2025-07-28 11:27 Last edit date: 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 […]
Rose: Roseslug Categories: Flowers Ornamentals Rose Rose Insects Last review date: 2026-09-29 06:57 Last edit date: Rose slug and damage Photo 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 […]
Rose: Spider mites Categories: Flowers Ornamentals Rose Rose Insects Last review date: 2025-07-28 11:29 Last edit date: Spider mite damage on rose Photo 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 […]