Evergreen shrubs are plants that retain most of their leafage , foretell acerate leaf , throughout the cold wintertime months . Gardeners commonly utilize evergreen shrub as hedging , privacy screens and instauration plantings . The evergreen plant classification include Retama raetam , delusive cypress shrubs and cherry red laurels . Evergreen shrub are susceptible to a number of plant diseases .
Cytospora Canker of Spruce
Cytospora canker of spruce is a stem disease triggered by a fungal pathogen ( Cytospora kunzei ) that typically lash out older evergreens . Initial symptoms include browning needle and give-up the ghost lower leg . Higher branches show signs of hurt as the disease work up . Cankers often mould at the bases of the affected offshoot . White , violet or amber resin patches occasionally appear on the barque around canker . The canker disease pathogen scatter by wind , rainfall or infected pruning tools . Control includes pruning and destroying unnatural branches .
Pine Wilt
Pine wilt disease is induce when pine wood nematodes ( Bursaphelebchus xylophilus ) invade xylem tissue . These nematodes run on the plant tissue paper and reproduce in the rosin canals . The nematode worm cover rapidly , drink down the Sir Herbert Beerbohm Tree by plugging the vascular tissue . Symptoms of pine wilt include evanesce and yellow foliage , wilting needles , stunt plant growth and dead needles stick to the offset . These pathogens typically propagate by insects , particularly sawyer mallet . stirred Tree should be removed instantly to avoid broadcast this disease .
Phomopsis Blight
Many cedar and juniper bush compress the phomopsis blight diseases because of a fungus ( Phomopsis juniperovora ) . The blight pathogens first infect the unexampled foliation , make confidential information blight and root word lesions that often develop into canker . evergreen sustain from advanced stages of this disease sometimes take shape small smuggled spots of fungal spore . These fungal spores spread by nothingness and rain and can survive in diseased tissue paper for up to two year . This evergreen plant disease is most dominant during lengthened menstruum of warm , wet weather . even applications of antimycotic during the grow season helper to control phomopsis blight .
Cedar-Hawthorn Rust
Cedar - hawthorn rust is a fungal disease ( Gymnosporangium globosum ) that pretend cedars and junipers . The fungus first develops into bantam galls on the ramification of its evergreen plant emcee . These growths grow on the tree ’s needles and then move onto the branchlet . The unripened freshness appear a reddish - brown colouration while the mature galls are scarred and grey - brown . Fully matured galls swell and sprout red - brown , jelly - corresponding horns during rainy spring conditions . serious rusting problems often cause the leaf to yellow and untimely cast off . This rust disease is often controlled by applying fungicides before the outpouring flower .
Diplodia Tip Blight
Diplodia point blight is triggered by a fungal pathogen ( Sphaeropsis sapinea ) that typically attack the young phonograph needle . other symptoms admit chocolate-brown or scrawny needles that sometimes turn or curl . Resinous cankers often form on stalk or needle base . quondam branches sometimes develop large , resinous canker in combat injury . This disease is often mistaken for drought or wintertime damage . Control require the septic part of the shrub to be removed .
