Skip to Left navigation Skip to Main content Skip to Footer

University of Minnesota Extension

Extension > Garden > Diagnose a problem > What's wrong with my plant? > Evergreen Trees and Shrubs > Pine > Needles half green, half brown

Print Icon Email Icon Share Icon

Pine > Needles > Needles half green, half brown

1 of 5
  • De-icing salt injury 1
  • De-icing salt injury 2
  • De-icing salt injury 3

De-icing salt

  • Needles brown from the tips down
  • Affected needles more common on side of tree facing the source of salt
  • Premature needle drop
  • Buds or candles may be killed
  • Reduced growth with prolonged contact
  • More information on De-icing salt injury
2 of 5
  • Dothistroma needle blight 1
  • Dothistroma needle blight 2
  • Dothistroma needle blight 3

Dothistroma needle blight
Mycosphaerella pini

  • Tan to brown spots on 1 yr. or older needles turn red in the sun
  • Needle tips are tan, bases remain green, scattered with brown or red spots
  • Tiny, raised, black pimple-like fungal spore producing structures form on dead needle tissue
  • Diseased needles turn completely brown and eventually drop
  • Lower portions of tree are most severely affected
  • Most common on Austrian and ponderosa pine; Scots pine has some resistance
  • Lab analysis is often necessary to distinguish Dothistroma needle blight from Brown spot
  • More information on Dothistroma needle blight
3 of 5
  • Brown spot needle blight 1
  • Brown spot needle blight 2
  • Brown spot needle blight 3

Brown spot needle blight
Mycosphaerella dearnessii

  • Small yellow to brown, resin-soaked spots form on 1 yr old needles in June-Aug
  • Often needle tip is killed and turns tan, base of needle remains green with random yellow to brown spots
  • Tiny, raised, black pimple-like fungal spore producing structures form on dead needle tissue
  • Diseased needles fall off in autumn
  • Infections are most common on lower branches
  • Outbreaks favored by prolonged wet weather in June and July
  • Scots pine most commonly infected; many Minnesota pines are susceptible
  • Lab analysis is often necessary to distinguish Brown spot from Dothistroma needle blight
  • More information on brown spot needle blight
4 of 5
  • Winter injury 1
  • Winter injury 2
  • Winter injury 3

Winter injury

  • Needles turn brown in late winter-early spring
  • Needles turn brown from the tip down, needle base often remains green
  • Needles at the tip of the branch are more severely discolored than those close to the trunk
  • Damage often only on one side of the tree
  • Common on trees exposed to wind and sun or light reflecting off buildings
  • Damage most severe at the top of the tree, branches covered by snow are unaffected
  • More information on Winter injury
5 of 5
  • Scleroderris canker  1
  • Scleroderris canker  2
  • Scleroderris canker  3

Scleroderris canker
Gremmeniella abietina

  • Needle clusters turn brown from the base up and are easily pulled off the branch
  • Infected needles fall off in summer
  • Buds on infected twigs fail to open
  • Cutting into branch below discolored needles reveals yellow-green discoloration
  • Cankers can kill branches or move into main stem and become perennial
  • Damage is greatest to small
  • Jack and red pine most commonly affected
  • More information on Scleroderris canker

Don't see what you're looking for?