Spruce: Oil discoloration of foliage categories: Conifers Ornamentals Spruce Spruce Diseases revision date: 2023-02-07 12:00 Discoloration on older foliage from oil applicationPhoto 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 instance) can […]
Spruce: Rhizosphaera needle cast categories: Conifers Ornamentals Spruce Spruce Diseases revision date: 2023-02-07 12:00 Spruce Rhizosphaera needle castPhoto 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. The needles […]
Spruce: Rust categories: Conifers Ornamentals Spruce Spruce Diseases revision date: 2023-02-07 12:00 Photo by: R.S. BytherSpruce 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’ brooms, or abnormally bushy […]