Approximately 130 species of deciduous and occasionally evergreen Acers exist. They are native to Asia. The type species of the genus is the sycamore (Acer pseudoplatanus) The maple leaf is a symbol of strength and endurance and is the national tree of Canada and a symbol of Hiroshima. Acers are often renowned for their autumn colour. Their distinctive seeds are know as helicopters, keys, or whirlybirds.
Culture for Maple
Acer trees grow between 10 and 45 meters high, however some shrub types will grow much smaller. They have dense root systems which may inhibit the growth of nearby vegetation. Acers prefer moist well drained soil and will tolerate moderate shade. Acers are generally regarded as being acid loving trees, the Norway maple (A. platanoides) preferring a soil pH between 4 7.5 however some Japanese Acers will thrive up to a pH of 8.
Concerns about Maple
Aphids are common pests of Acers. Tar spot is also a common fungal disease which affects A. platanoides, A. saccharinum and A. pseudoplatanus but this disease will not generally kill trees. Verticillium wilt causes significant damage including branch dieback. Sooty back disease will also kill whole trees, most communally associated with periods of drought. Asian long horned beetle is threatening maples in the United States and Canada but this insect is currently not thought to be present within the UK.
Management Practices for Maple
Treat aphids and fungal disease with a suitable insecticide or fungicide respectively, as necessary. Ensure soil moisture is suitable. Removal of dead and dying limbs is critical in preventing the spread of diseases such as verticillium. Ensure soil pH is adequate ensure correct acidity to ensure the best autumn colour.