Cherry laurel, Prunus laurocerasus, is a large-sized, broadleaved shrub that belongs to the same family as cherry and almond. Evergreen cherry laurel grows as a large shrub or small tree with a mature height of about 20 feet, with a 6- to 10-foot spread. The leathery, dark green foliage is 3 to 7 inches long and up to 2 inches wide. The plant blooms with white flowers in mid-spring followed by small, black fruit in fall. Cherry laurel is susceptible to a number of problems.
Shot hole is cited as a potential fungal disease of cherry laurel by Clemson Cooperative Extension. The disease primarily appears as small, red lesions on the foliage that gradually enlarge, developing tan centres and purple edges. Though the lesions also appear on the twigs and flowers, the spots are less evident in these areas. As the disease progresses, the centres of the lesions fall out, leaving shot-hole like holes on the foliage. Control options include monitoring the plants regularly and applying recommended fungicides in the early stages of the disease. The University of California Statewide Integrated Pest Management Program says effective fungicides for shot hole include iprodione, azoxystrobin and trifloxystrobin.
Cherry laurel is susceptible to the fungus Botryosphaeria, which causes limb dieback. The disease is most prevalent during late April and is characterised by the yellowing and browning of the lower limbs on the affected trees. As disease progresses, the limbs gradually die. Removing bark on affected limbs reveals brown spots on the wood. Management of disease includes maintaining vigorous plant health with adequate watering and fertilisation. The control of scales is also one of the important management options. The use of fungicides is not effective.
Collar, Foot, Root and Crown Rot
Collar, foot, root and crown rots are considered potential problems of cherry laurel by the University of California Extension. The different rots are caused by a number of species of the Phytophthora fungi that commonly infect the crowns and roots of a wide range of plants. The disease is characterised by plant wilting with discoloured and stunted foliage and premature leaf drop. There is often a dark grey to brown discolouration under the bark with black to red sap secretions from darkened stem areas. Management includes avoiding planting in poorly drained sites and using disease-resistant varieties. Fungicidal option includes fosetyl-al.