Spruce: Oil discoloration of foliage Categories: Conifers Ornamentals Spruce Spruce Diseases Last review date: 2025-07-31 02:17 Discoloration on older foliage from oil application Photo by: R. Maleike Biology Oil discoloration of spruce foliage is suspected when trees which normally have blue-green needles instead have bright green needles. Use of spray oils (to control insects, for […]
Spruce: Rhizosphaera needle cast Categories: Conifers Ornamentals Spruce Spruce Diseases Last review date: 2025-07-31 02:24 Spruce Rhizosphaera needle cast Photo by: R.S. Byther Biology The first symptoms occur in late summer, when a yellow mottling develops on the current season’s needles. During the fall to early spring, the infected needles turn brown or purplish brown. […]
Spruce: Rust Categories: Conifers Ornamentals Spruce Spruce Diseases Last review date: 2025-07-31 02:38 Photo by: R.S. Byther Spruce rust Biology Spruce rusts are fungal diseases that sometimes require an alternate host to complete their life cycle. There are many rust diseases of spruce, each with different alternate hosts. One spruce rust causes witches’ broom, or […]