True Fir: Annosus root rot categories: Conifers Ornamentals True Fir True Fir Diseases last review date: 2026-01-29 12:02 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. It can live […]
True Fir: Armillaria root rot categories: Conifers Ornamentals True Fir True Fir Diseases last review date: 2026-01-29 12:13 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 soils or soils […]
True Fir: Current-season needle necrosis categories: Conifers Ornamentals True Fir True Fir Diseases last review date: 2026-01-29 12:49 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 after growth begins, […]
True Fir: Flowers categories: Conifers Ornamentals True Fir True Fir Diseases last review date: 2023-02-07 12:00 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) in the Landscape” […]
True Fir: Grovesiella canker categories: Conifers Ornamentals True Fir True Fir Diseases last review date: 2026-01-29 01:10 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 develop on one-year-old […]
True Fir: Interior needle blight categories: Conifers Ornamentals True Fir True Fir Diseases last review date: 2026-01-29 01:29 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 with the disease, […]
True Fir: Needle casts categories: Conifers Ornamentals True Fir True Fir Diseases last review date: 2026-01-29 02:11 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 current-season and one-year-old […]
True Fir: Phytophthora root rot categories: Conifers Ornamentals True Fir True Fir Diseases last review date: 2026-01-29 02:20 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 die. The infection […]
True Fir: Rust (Pucciniastrum) categories: Conifers Ornamentals True Fir Diseases last review date: 2026-01-27 03:21 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 needles in early […]
True Fir: Rust (Uredinopsis) categories: Conifers Ornamentals True Fir True Fir Diseases last review date: 2026-01-27 02:54 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 season needles in […]