Apr 19-21 10am-5pm
Mon-Fri 9am-9pm
Sat-Sun 9am-6pm


 Pests on EvergreensDiseasesCultural Disorders






Select the pest from the images below for more information:

AphidsPine False WebwormPine Needle ScalePine Tortoise Scale






Spider MitesSpruce BudwormSpruce Gall AdelgridWestern Tussock Moth






White Pine WeevilYellowhead Spruce Sawfly







Plants affected:  Numerous indoor and outdoor plants

Symptoms:  Severe infestations will cause curling/twisting of foliage, flowers to wilt and drop.

Life Cycle:  Eggs hatch on host plants in spring, these nymphs give birth to ‘daughters’, within days the daughters give birth - up to 30 generations per summer

Cultural Control:
• Ladybird beetles/larvae, lacewings are natural predators
• Strong jet of water to knock aphids off plants

Chemical Control:  Doktor Doom House and Garden, End All, Ambush

Pine False Webworm

Pine False WebwormPine False WebwormPlants Affected - Pine

Symptoms - Silken feeding tubes filled with needles, frass and cast skins.

Life Cycle:
Overwinter as larvae in soil beneath tree
Adults emerge in spring, mate and female lays egg on last year’s needles
Larvae hatch in 2 weeks, crawl to base of needle and feed
Larvae create tubes along branch from within which they feed
Feeding complete by late June when larvae drop to ground to overwinter

Cultural Controls - Remove larvae by hand

Chemical Controls:

Pine Needle Scale

Pine Needle ScalePine Needle ScalePlants Affected - White/Colorado Spruce, Scot’s/Lodgepole Pine, Douglas Fir and other Spruce


  • As scale feeds, yellow/green spots develop on needles
  • Branches take on unhealthy grey appearance
  • Scales are white, appear as flecks of white paint on needles

Life Cycle: Overwinter as eggs underneath the scale hatch in spring and move to other needles and hosts.  Mating and egg laying occur in August.

Controls - Chemical:
Malathion - apply shortly after new growth appears in early or Mid June
• Can re-spray in early August before females form their hard shell

Pine Tortoise Scale

Pine tortoise ScalePlants Affected - Mostly Scots, Jack and Austrian Pine


  • Scales resemble tiny tortoises up to 1/4" long.  Appear on 1-2 year shoots
  • Severe infestations result in decreased plant vigor, sooty mold from honeydew secreted by the insect

Life Cycle:  Immature females overwinter, resume growth in spring, mature in June.  Eggs are then laid beneath female, up to 500 each!

Controls - Cultural or Non-chemical:  Prune away damaged stems

Controls - Chemical:  Malathion - apply shortly after new growth appears in early or Mid June, when immature crawlers are active.

Spider Mites

Spider MitesSpider MitesPlants affected:  Spruce, Pine

Affects lower and center of tree
• Webbing - very fine
• Appears in hot, dry weather

Life Cycle:
• Adults come out of dormancy in spring
• Lay as many as 100 eggs in 2 week lifespan. Eggs hatch anywhere from 5-25 days
• Several generations per season. In fall, their exteriors harden, go into hibernation, can survive very harsh winters

Cultural Control:  Strong jet of water

Chemical Control:
• Malathion
• Ambush

Spruce Budworm

Spruce BudwormSpruce BudwormPlants Affected - Spruce

• Lots of feces, webbing
• Insect has a brown/black head—so as not to confuse it with yellowheaded spruce sawfly. Young larvae are yellow green bodied, older cinnamon brown bodied.

Controls - Cultural or Non-chemical:
Handpick small infestations
• Have some natural predators

Controls - Chemical:
• Malathion

Spruce Gall Adelgid

Spruce Gall AdelgridSpruce Gall AdelgridPlants Affected - Spruce, Douglas Fir

Damage cosmetic
• Early spring white fluff may occur, followed by galls
• Damage is usually 8’ or lower

Controls - Cultural or Non-chemical:
Hose down white fluff
• Hand prune galls (green/purple ones still have adults inside).

Controls - Chemical:  Watch for female nymphs feeding in early spring; spray with malathion

 Western Tussock Moth

Plants Affected - Many trees/evergreens

Needles are chewed, leaving little stubs
• Primarily feed on newer growth closer to tops of tree, then down
• Caterpillar is furry, two long black antennae and 4 distinct furry tufts on top of body. Brightly coloured spots

Life Cycle - Overwinter as eggs, emerge in spring and start feeding. Mate, hundreds of eggs are laid and larvae stages feed heavily

Biological Control - BTK

Chemical Control - Need to monitor early in season, if large populations occur, spry with Ambush

White Pine Weevil

White Pine WeevilWhite Pine WeevilWhite Pine WeevilPlants Affected:  Pine

• Possible resin leaking
• Punctures capped w/black near top of leader
• In late June/July, drooping/wilting, shepherd’s crook at top
• Emergence holes from adults seen after this

Life Cycle:
• Adults emerge in early spring, lay eggs in leader
• Larvae then feed downward
• Cocoons form in late July, then adults emerge Aug-Sept

Cultural Controls:
• Remove leader
• Trees must be kept healthy (well watered)

Chemical Controls:  None

Yellowhead Spruce Sawfly

Yellowhead Spruce SawflyYellowhead Spruce SawflyPlants Affected - Spruce

• Clean cut needles, strong resin scent
• Feed on new needles first ‘clean feeders’
• No webbing, feces

Life Cycle:
• Adults emerge from ground in late May, lay eggs at base of needle
• Eggs hatch 5-10 days later, feed for 30-40 days
• At maturity, drop to ground, form cocoon

Cultural Controls:
• If infestations small, hand pick
• Strong jet of water

Chemical Controls:
• Ambush
• Malathion

Select the disease from the images below for more information:

 Cytospora CankerNeedle CastSirococcus Tip BlightSooty Mold





Cytospora Canker

Cytospora CankerCytospora CankerPlants affected: Evergreens

• Needles start off yellow, in summer turn purple
• During periods of wetness, gelatinous threads can be seen
• Cankers form with sunken ridges, girdle branches, cause dieback

Life Cycle: Secondary fungal disease - moves in on sun scalded wood, stressed trees.

Cultural Control:
• Pruning
• Keep trees healthy and well watered

Chemical Control: None

Needle Cast

Needle CastNeedle CastPlants Affected: Spruce trees

• Mimics winter injury
• Starts as light green to yellow spots, which turns to brown or red
• Black spores will be seen on needles prior to drop (early spring)

Life Cycle:  Fungus, spores infect new growth, damage appears next spring

Cultural Controls: Keep trees healthy and well watered

Chemical Controls: None

Sirococcus Tip BlightSirococcus Tip BlightSirococcus Tip Blight

Plants affected: Spruce (Colorado, white, Norway) and Pine (Mugo, Scots, Jack)

• Browning, wilting, curling of young shoots, most often on lower growth
• Infected shoots have a hooked appearance and eventually lose all needles
• Small purplish cankers may appear on current year growth

Life Cycle: Overwinters on infected plant material, cool wet springs facilitate the spread of the disease onto new or current year’s growth

Cultural Controls: Remove and destroy affected needles/shoots on a regular basis

Chemical Controls: Copper spray starting mid June at 10 day intervals

Sooty MoldSooty Mold

Plants affected:  Evergreens; can be found on trees/shrubs as well

• Sooty growth on branches
• Caused by a fungi that is living off of sap from tree wounds or honeydew from aphids/scale
• Does not harm tree (only severe cases will limit photosynthesis somewhat)

Cultural Controls:  Can prune out severely damaged branches, wash off soot with soapy water/strong jet of water

Disorders are plant abnormalities that are caused by environmental factors such as nutrient availability or temperature (not pests or diseases). Typically, disorders may make your plant look different than expected but unless severe, are not usually overly harmful.
Select the disorder from the images below for more information:

Evergreen Winter DamageGummosisHerbicide damageOverwateringUnderwatering





Evergreen Winter DamageEvergreen Winter Damage

• winter winds, light reflecting off snow cause needles to brown, die off
• sometimes symptoms not seen until spring, if damaged primarily on south side of plant this is sunscald

• ensure proper placement of susceptible plants (cedar, boxwood, long needle pine)
• plants should be thoroughly watered prior to final freeze up in autumn


 Frost crackingFrost Crack

• vertical cracks present in bark on trunks of trees
• fruit trees very susceptible to this

• due to fluctuating temperatures in winter months
• mulch bases of trees with bark mulch, ensure plants are well hydrated before final freeze up in autumn




• very common on fruit trees, especially cherries

• causes vary from mechanical damages such as sapsucker damage, squirrel damage, wood boring insects or delayed winter injury, which is common in fruit trees
• beyond avoiding these, let the wounds heal over on their own

Herbicide damage

Herbicide Damage

• curling or cupping leaves
• discoloration between veins
• twisted, elongated stems

• use all herbicides according to label, note that herbicide can drift for several miles, it’s very difficult to ascertain where chemical drifts from
• keep damaged plants well-watered, most plants will recover


• wilting, yellowing leaves
• leaves will yellow from outside in
• Note: wilting is a symptom of BOTH over and underwatering, if plants are wilting don’t assume they require moisture until soil is checked by hand

• plants in lower lying areas will suffer in times of heavy rains; plant appropriate species in these areas
• for new and established plants, water only as required; check soil prior to watering

Underwatering EvergreensUnderwatering

• wilting, crispy or browned leaf edges

• water, especially for new transplants should be monitored daily during periods of extreme heat
• for new transplants, stick your hand into the soil to determine if moisture is required