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OVERALL APPEARANCE
Symptoms: Cause: Solution:
White fluff on needles in the spring. Some needles may drop. Green to purple galls (2.5 - 5 cm) develop on tips of branches. Cooley Spruce Gall Aphids (also see Aphids above). Remove galls from trees and burn them. Spray Diazinon at bud-burst or Latox in May. Thoroughly spray trees to point of run-off.
Small, white specks on the needles. Needles drop and tree vigor is reduced. Pine Needle Scale. Also see Scale Insects. Use Dormant Oil in the dormant season. Spray Diazinon or Malathion in late May or early June and repeat in 3 weeks.
NOTE: Malathion and Dormant Oil may discolour Blue Spruce
The inside of the Spruce tree becomes bare. Needles drop. Newer needles stay green. Spruce Aphids. Small, dull-green insects feed on needles from February till mid-summer (also see Aphids above). When damage is first noticed, spray with Diazinon and repeat every 2 weeks until problem is solved.
Silken webs cover the needles and shoots. Needles are stippled yellow and look dirty. Hold a white piece of paper under a branch and tap the foliage. Dark green or red or black specks will drop on the paper. Spider Mites. Use Latox in early spring and repeat 3 times at 10 day intervals.
In western Canada needles are eaten by orange, hairy caterpillars, first at the top of the tree and progressing downward. Tussock Moths. Click on the insect name for more information and controls.
Needles on branches closest to the ground turn brown. Amber-coloured pitch oozes from bark. This pitch turns white when it dries. Canker. Also see below. Click on the disease name for more information and controls.
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on LEAVES, BRANCHES and STEMS
Symptoms: Cause: Solution:
Needles are webbed together, surrounded by sawdust-like material. Light-green or greenish-brown caterpillars (6 mm) can be found in April. Spruce Needle Miners. Adult Moths are flying in May. Spray Lagon 2E or Diazinon in early April and repeat in May and June.
Leaders are killed by cream-coloured weevil larvae (7 mm) that bore inside. Spruce Weevils. Reddish-brown adults with patches of gray scales are present in April and May, laying eggs. Prune off and burn affected leaders. Tie a side branch in an upright position as this will form a new leader. Spray Diazinon or Methoxychlor in April and May and again in August and September.
2.5 cm caterpillars are eating the needles in May and early June. Spruce Budworms. Use Sevin, Lagon 2E or Malathion when damage or worms are first noticed.
NOTE: Malathion may discolour Blue Spruce
Needles turn yellow, then brown and drop, leaving unsightly bare branches. Branches and trunks of trees have discoloured, sometimes sunken spots and areas. Bark may be splitting or cracking and peeling away. Amber resin exudes from cankers and hardens to a white crust. Common in Colorado Blue and Norway and White Spruce. Cytospora Canker. Click on the disease name for more information and controls.
In late summer or early fall needles of Blue and White Spruce show a yellow mottling. These needles will turn a purplish-brown. Tiny black dots are noticeable on the needles. Needle Cast (fungus) (Rhizophaera). Rake up and destroy fallen needles. Use Copper Spray in the spring when new growth starts and repeat.
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General Information

Plant in a full sun location, but these trees will tolerate partial shade.

Soil should be well drained

Water to wet soil 1 meter deep.

Companion Plants:

Fertilizer: Evergreen food.