Tulip : Break (viruses) Categories: Bulbs Ornamentals Tulip Tulip Diseases Last review date: 2026-01-27 01:52 Tulip break (virus) causing irregular tulip color Photo by: R.S. Byther Biology Several viruses affecting tulips are spread by many species of aphids. Viruses overwinter in infected bulbs. White and yellow cultivars do not exhibit obvious symptoms and therefore may […]
Tulip: Fire Categories: Bulbs Ornamentals Tulip Tulip Diseases Last review date: 2026-01-27 01:40 Tulip fire damage: black sclerotia Photo by: R.S. Byther Biology Tulip fire is caused by a fungus that overwinters in soil, affected bulbs and diseased plant debris. Flowers are quite susceptible. Water soaked spots and dead spots occur on flowers. Severe infections […]
Narcissus (Daffodil): Basal rot Categories: Bulbs Narcissus (Daffodil) Narcissus (Daffodil) Diseases Ornamentals Last review date: 2024-07-07 01:55 Narcissus basal rot Photo by: R.S. Byther Biology Basal rot of narcissus is caused by a soilborne fungus. Bulbs usually develop the rot during storage. The infection begins at wound sites or at the base of the bulb […]
Narcissus (Daffodil): Fire Categories: Bulbs Narcissus (Daffodil) Narcissus (Daffodil) Diseases Ornamentals Last review date: 2024-07-07 01:58 Narcissus fire Photo by: R.S. Byther Biology Narcissus fire is a fungal disease which affects the petals and leaves, but does not affect the bulb. It is favored by warm, humid weather and can spread very quickly under these […]
Narcissus (Daffodil): Leaf scorch Categories: Bulbs Narcissus (Daffodil) Narcissus (Daffodil) Diseases Ornamentals Last review date: 2023-02-08 12:00 Narcissus leaf scorch Photo by: R.S. Byther Biology Leaf scorch is caused by a fungus that survives in the necks of the bulbs (thus infecting emerging leaves) and also in infected foliage. Leaf tips develop yellow-brown to reddish […]
Narcissus (Daffodil): Stem and bulb nematode Categories: Bulbs Narcissus (Daffodil) Narcissus (Daffodil) Diseases Ornamentals Last review date: 2024-07-07 02:00 Narcissus nematode damage Photo by: R.S. Byther Biology Nematodes are tiny (often microscopic), parasitic worms that live in the soil and in infected plant parts. The stem and bulb nematode of narcissus feeds mainly on aboveground […]
Narcissus (Daffodil): Virus diseases Categories: Bulbs Narcissus (Daffodil) Narcissus (Daffodil) Diseases Ornamentals Last review date: 2025-10-31 08:39 Narcissus yellow stripe virus Photo by: R.S. Byther Biology While many viruses infect narcissus, two virus diseases (Yellow Stripe and White Streak) are common in the Pacific Northwest. Yellow Stripe is characterized by the white mottling or streaking […]
Narcissus (Daffodil): Narcissus bulb fly Categories: Bulbs Narcissus (Daffodil) Narcissus (Daffodil) Insects Ornamentals Last review date: 2025-10-30 03:40 Narcissus bulb fly Photo by: R.S. Byther Biology The adult narcissus bulb fly is about 1⁄2″ long and closely resembles a small bumblebee. The female lays eggs near the bulbs in early summer. The hatching maggots burrow […]
Iris: Leaf spot Categories: Bulbs Iris Iris Diseases Ornamentals Last review date: 2025-10-30 04:53 Iris leaf spot Photo by: R.S. Byther Biology Leaf spot is caused by a fungus which overwinters on dead leaves and other plant material. Spores develop in spring and infect leaves. Several cycles can occur in warm, wet weather, and the […]
Iris: Bulb mite Categories: Bulbs Iris Iris Insects Ornamentals Last review date: 2025-10-30 04:56 Iris bulb mites Photo by: A.L. Antonelli Biology Bulb mites are a typical pest of iris in Washington both in the gardens and in storage. Injured or bruised bulbs are the most susceptible to damage. Not only do mites destroy bulb […]
Gladiolus: Thrips Categories: Bulbs Gladiolus Gladiolus Insects Ornamentals Last review date: 2025-10-30 05:00 Gladiolus thrips damage Photo by: R.S. Byther Biology Gladiolus thrips are tiny insects with feather-like wings, an unusual design in the insect world. They have rasping mouthparts that cause feeding damage characterized as elongated stippling on leaves and flowers, eventually making plant […]
Daylily: Daylily gall midge Categories: Bulbs Daylily Daylily Insects Ornamentals Last review date: 2025-11-08 08:48 Daylily gall midge larvae & damage to bud Photo by: D. Pehling Biology The daylily or Hemerocallis gall midge (Contarinia quinquenotata) is the larva of a small, nondescript, grayish-brown fly. The adult fly overwinters in the soil and emerges in […]
Daylily: Thrips Categories: Bulbs Daylily Daylily Insects Ornamentals Last review date: 2025-11-08 09:02 thrips damage on gladiolus Photo by: R.S. Byther Biology Several species of thrips may be found on daylilies. Thrips are tiny (usually less than 1⁄8 inch long), fast-moving insects often found on leaves and between flower petals. Adults are typically yellow to […]
Dahlia: Virus Categories: Bulbs Dahlia Dahlia Diseases Ornamentals Last review date: 2025-11-08 09:16 Dahlia mosaic virus symptoms Photo by: R.S. Byther Biology Tomato spotted wilt virus (thrips vector) induces a yellow-green mosaic, irregular concentric rings, or even wavy-lines in older leaves. Dahlia mosaic virus (aphid vector) produces chlorosis along veins and may shorten internodes, facilitating […]
Dahlia: Earwigs Categories: Bulbs Dahlia Dahlia Insects Ornamentals Last review date: 2025-11-08 09:24 Earwig as nuisance pest on flowers Photo by: M. Bush Biology Earwigs are reddish-brown insects about 3⁄4 inch or less in length. Both males and females have pincers at the rear end. Earwigs are largely beneficial, feeding on many pests such as […]
Dahlia: Western spotted cucumber beetle Categories: Bulbs Dahlia Dahlia Insects Ornamentals Last review date: 2025-11-08 09:31 Western spotted cucumber beetle Photo by: K. Grey Biology The western spotted cucumber beetle is a pest of many ornamentals and vegetables. About 1⁄4″ long, the adult beetles have yellow wing covers with black spots. The rest of the […]