Flowering cherries are members of the genus Prunus, which also includes peaches, plums, apricots, and almonds. The profusion of flowers in spring makes them a very popular ornamental tree; over two hundred species exist most of which are fully hardy to frosts.
Culture for Flowering Cherries
The cultural requirements of cherries vary with rootstock and variety, but all require full sun and well-drained soil. Cherry trees are easily damaged by planting too deeply or by allowing mulch to remain against the lower trunk. They respond well to fertilisation, which helps keep the trees growing vigorously and able to resist pest problems.
Concerns about Flowering Cherries
Cherry brown rot (aka ‘blossom blight) is a fungal disease that can cause defoliation, tip blight, blossom blight, and twig dieback. Cherry bark tortrix (CBT) larvae bore into trunks and major limbs, eventually causing branch dieback. Shothole disease of foliage is also common in Prunus species. Shothole borer is a small beetle that mainly attacks stressed cherries. Many fungi including bacterial canker, crown gall, and cytospora dieback attack trees weakened by transplanting and environmental stress. Root rots are caused by Phytophthora, Armillaria, and other fungi; mainly a problem in poorly drained, heavy soils. Blossom wilt, leaf spots, powdery mildew and soot moulds which reduce leaf photosynthetic area and disfigure the tree. Heavy fruit and flower production leads to high nutrient demands. Also susceptible to various scale insects and aphids.
Management Practices for Flowering Cherries
The key to successful pest and disease management of cherries are early (mid-April to late May) sprays of insecticides, fungicides, and/or copper. At least three, ideally four, sprays need to be applied. Commencing sprays in June will produce little control. Air-spading to alleviate soil compaction and control honey fungus/Phytophthora combined with soil applications of biochar, appropriate fertilisers, phosphites, and mulch. Apply preventative fungicide applications in spring to manage brown rot and shothole disease. If CBT frass is detected, bark treatments in spring and fall are effective in managing the pest over time. Excavate root collars to avoid decay and attack by clearwing moth borers.