All Christmas tree species, especially noble fir
- Environmental stress, such as low light levels or moisture stress, can accelerate the yellowing and dropping of older needles.
- Loss of interior, older needles
- Older needles turn yellow prior to shedding (late summer and early fall)
- Older needles easily shed from the stems
- Use mechanical shakers to minimize the problems on harvested trees.
- Use high-velocity air (leaf blowers) to remove unsightly needles.
- Interior needle blight syndrome on noble and grand fir
- Other fungal needle casts
