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Extension > Garden > Diagnose a problem > What's wrong with my plant? > Evergreen Trees and Shrubs > Fir > Yellow to reddish-brown needles

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Fir > Needles > Yellow to reddish-brown needles on part to most of tree

1 of 6
  • Glyphosate herbicide damage 1
  • Glyphosate herbicide damage 2
  • Glyphosate herbicide damage 3

Glyphosate herbicide damage
(e.g. Roundup)

  • Needles retain shape but turn pale yellow to reddish-brown
  • If damage is severe, needles drop and branches may die
  • Symptoms occur a few days to several weeks after herbicide application
  • Dead or dying weeds expressing similar symptoms may be present nearby
  • More information on Glyphosate herbicide damage...
2 of 6
  • Spruce budworm 1
  • Spruce budworm 2
  • Spruce budworm 3

Spruce budworm
Choristoneura fumiferana

  • Branch tips or branches defoliated
  • Needles webbed together in clumps attached to twigs, turning reddish brown by July
  • Light to moderate infestations confined to upper crown
  • Prefers balsam fir; also feeds on spruce, pine and larch
  • Larva has black head, light brown to gray brown with small spots, up to 1 inch long
  • More information on Spruce budworm...
3 of 6
  • Fir needle rusts 1
  • Fir needle rusts 2
  • Fir needle rusts 3

Fir needle rusts
Fir-fern (Uredinopsis spp., Milesina spp.), Fir-fireweed (Pucciniastrum epilobii), Fir-blueberry (Pucciniastrum goeppertianum)

  • Current year needles turn yellow and sometimes curl
  • Diseased needles may turn brown and drop prematurely resulting in thin foliage
  • White or yellow tube-shaped spore producing structures form on the underside of infected needles
  • Difficult to distinguish between these diseases in the field; lab analysis often required
  • Rust infection on nearby alternate host, fern, fireweed or blueberry may aid in diagnosis
  • More information on Fir needle rusts...
4 of 6
  • Lirula needle blight 1
  • Lirula needle blight 2
  • Lirula needle blight 3

Lirula needle blight
Lirula mirabilis and L. nervata

  • 1 yr old needles reddish-brown in June and July
  • Diseased needles turn gray with age and remain attached for several years
  • L. nervata – a raised black line develops along the midrib of infected 3-4 yr old needles
  • L. mirabilis - 2 raised lines, the color of the needle, develop parallel to the midrib of 3-4 yr old needles
  • Lower branches most affected
  • Cool, wet weather favors this disease
  • More information on Lirula needle blight...
5 of 6
  • Pine spittlebug 1
  • Pine spittlebug 2
  • Pine spittlebug 3

Pine spittlebug
Aphrophora parallela

  • White foamy mass on twigs and needles May to early June
  • Look within for small (up to ¼ inch), black and pale yellow nymphs
  • Heavy infestations can flag and discolor shoots
  • More information on Pine spittlebug...
6 of 6
  • Rhizosphaera needle cast 1
  • Rhizosphaera needle cast 2

Rhizosphaera needle cast
Rhizosphaera pini

  • Drooping, grayish-tan needles in late spring or early summer
  • Needles at the branch tips remain green, while older needles closer to the trunk of the tree become discolored
  • Tiny black dots can be seen with a hand lens on infected needles
  • Discolored needles fall off mid-summer; tree looks thin and bare
  • Damage typically starts on the lower branches and moves up the tree
  • More information on Rhizosphaera needle cast...

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