Magnolia macrophylla aka Big Leaf Magnolia

Bigleaf magnolia, Magnolia macrophylla, is a deciduous tree in the Magnoliaceae family. It grows wild from Ohio south to Florida and west to Arkansas and Louisiana. It is rare in the wild. Small, isolated groups grow in rich woods, river valleys and ravines. It has also naturalised in Illinois, Maryland, New York, Pennsylvania and Ontario.

In gardens it usually reaches 30 to 40 feet (9 to 12 m) tall, with a similar spread. Some trees pass 60 feet (18 m). British sources give a smaller size of 26 to 40 feet (8 to 12 m) high and 13 to 26 feet (4 to 8 m) wide. Young trees are pyramidal on a single straight trunk. With age the crown becomes broad and rounded. Growth is slow, and a tree may take 12 years or more to flower.

The leaves are the main attraction. They are the largest simple leaves of any tree native to North America. Most are 1 to 3 feet (0.3 to 0.9 m) long, and some reach about 3 feet (1 m). They are oblong to obovate with a heart-shaped base and wavy, untoothed edges. The upper side is bright green, while the underside is silvery grey and downy. The leaves sit alternately but cluster near the shoot tips. The stout twigs carry large leaf scars and big buds covered in silvery hairs. The thin bark is smooth and grey-brown.

The flowers open in May and June. They are cup-shaped, creamy white and fragrant, and measure 8 to 14 inches (20 to 36 cm) across. Each has six to nine tepals, and the inner ones are purple at the base. The blooms often sit high in the crown and can be hard to see up close. Hairy, cone-like fruits follow and turn red or rose-pink in late summer. They split to show red seeds hanging on fine threads. Birds and small mammals eat these seeds. Butterflies and hummingbirds visit the flowers.

This tree likes moist, well-drained, humus-rich loam that is acid to neutral. It grows in full sun or light shade. It dislikes dry ground, waterlogged soil and urban pollution. Strong wind tears the huge leaves, so plant it in a sheltered spot. Late frosts can damage the flower buds. It is hardy to USDA zone 5 and rated H4 in the UK. Pruning is rarely needed. If you must prune, do it between midsummer and early autumn. Gardeners use it as a lawn specimen or shade tree with a tropical look.

US sources report no serious pest or disease problems. Magnolia scale, yellow poplar weevil and sooty mould sometimes appear. The RHS adds scale insects, capsid bug, coral spot and phytophthora. Honey fungus, grey mould and leaf spot can also occur. The fallen leaves make a big clean-up job in autumn. No edible uses are recorded.