True Fir: Annosus root rot Categories: Conifers Ornamentals True Fir True Fir Diseases Last review date: 2026-01-29 12:02 Last edit date: Annosus root rot decayed wood with black flecks Photo by: B.M. Johnson Biology Annosus root rot is caused by the fungus Heterobasidion annosum. This native soil pathogen is often in large old tree stumps. […]
True Fir: Armillaria root rot Categories: Conifers Ornamentals True Fir True Fir Diseases Last review date: 2026-01-29 12:13 Last edit date: White fungal mat of Armillaria root rot infecting trunk Photo by: C.R. Foss Biology Armillaria root rot is a fungal disease transmitted between plants by root contact. Armillaria is often found in newly cleared […]
True Fir: Current-season needle necrosis Categories: Conifers Ornamentals True Fir True Fir Diseases Last review date: 2026-01-29 12:49 Last edit date: Current-season needle necrosis Photo by: R.S. Byther Biology Current-season needle necrosis affects noble fir and grand fir. The cause is unknown but appears to be a cultural problem due to a mineral deficiency. Shortly […]
True Fir: Flowers Categories: Conifers Ornamentals True Fir True Fir Diseases Last review date: 2023-02-07 12:00 Last edit date: Fir flowers Photo by: R.S. Byther Biology Old, spent flower parts remaining on twigs can be misinterpreted as a disease or insect problem or an unusual growth anomaly. Management Options See “Using Integrated Pest Management (IPM) […]
True Fir: Grovesiella canker Categories: Conifers Ornamentals True Fir True Fir Diseases Last review date: 2026-01-29 01:10 Last edit date: Fir Grovesiella canker Photo by: R.S. Byther Biology Grovesiella canker is a fungal disease found mainly on the lower branches and stems of young trees or the lower branches of older trees. Sunken, dead areas […]
True Fir: Interior needle blight Categories: Conifers Ornamentals True Fir True Fir Diseases Last review date: 2026-01-29 01:29 Last edit date: Interior needle blight Photo by: G.A. Chastanger Biology Interior needle blight is found primarily on noble fir in Christmas tree plantings but may also occur in the landscape. While a fungus has been associated […]
True Fir: Needle casts Categories: Conifers Ornamentals True Fir True Fir Diseases Last review date: 2026-01-29 02:11 Last edit date: Fir needle cast symptoms Photo by: R.S. Byther Biology Needle casts on true fir are caused by several fungi. Infected trees develop brown or straw-colored needles which drop prematurely. Severely infected trees may have only […]
True Fir: Phytophthora root rot Categories: Conifers Ornamentals True Fir True Fir Diseases Last review date: 2026-01-29 02:20 Last edit date: Phytophthora root rot symptoms Photo by: R.S. Byther Biology Phytophthora root rot is usually a problem only in areas with poor drainage or where flooding occurs. The fungus attacks the roots, which rot and […]
True Fir: Rust (Pucciniastrum) Categories: Conifers Ornamentals True Fir Diseases Last review date: 2026-01-27 03:21 Last edit date: Fir Pucciniastrum rust Photo by: R.S. Byther Biology Pucciniastrum rust are fungal diseases. Yellowish spots or blotches appear on the upper side of infected needles. White, tube-like structures are typically found on the underside of last season’s […]
True Fir: Rust (Uredinopsis) Categories: Conifers Ornamentals True Fir True Fir Diseases Last review date: 2026-01-27 02:54 Last edit date: Fir Uredinopsis rust Photo by: R.S. Byther Biology Uredinopsis rust is a fungal disease. Yellowish spots or blotches appear on the upper side of infected needles. A slight discoloration may first be observed on current […]