The Japanese magnolia (Magnolia x soulangeana) is often called the "saucer magnolia" for its large, saucer-sized flowers. This deciduous tree blooms in early spring before the leaves appear, creating a dramatic and beautiful statement. The flowers range in color from a deep pink to creamy white, and are shaped somewhat like tulips. The Japanese magnolia can reach heights of 25 feet and is an excellent specimen tree, according to Edward F. Gilman, a horticulturist with the University of Florida.
The Japanese magnolia grows best in temperate zones where the winters are not extremely cold and the summers do not have long, hot periods of drought. The tree thrives in United States Department of Agriculture (USDA) Plant Hardiness Zones 5 through 9A, according to Gilman.
Exposure to sunlight is important for this tree to flower, but too much sunlight can cause the buds to develop early, which puts them in danger of being damaged by a late frost. If damaged by frost, the buds will not open and will instead drop from the tree. For this reason, it is best to plant the Japanese magnolia in a location where it will receive morning sunlight followed by filtered afternoon shade, especially in warmer climates.
Magolias grow best in loamy soil that is rich in organic matter. They prefer slightly acidic, moist soil that is also well-draining. Standing water can lead to foot rot, so heavy, waterlogged soil should be amended with peat moss to add nutrients and aid in drainage.
Keep the soil around your Japanese magnolia tree evenly moist, especially during periods of extended drought. Deep, slow watering is best. Use a soaking or drip hose to water the area around the tree. Let it run for several hours once or twice a week, depending on your climate, to thoroughly saturate the ground.
This tree is relatively disease- and pest-free, according to Gilman. Still, care should be taken to make sure the tree remains healthy. Magnolia scale, a sucking insect, can damage the tree, weakening it. Control this insect and others by applying an insecticidal oil to the tree in the spring. Fungi can cause leaf spot, which does not kill but causes unattractive spots to develop on the leaves, and canker growth, which can kill branches. Branches with cankers (sunken, black, cracked areas of wood) should be pruned off. A fungicide applied in the spring can reduce the chances of the development of fungal diseases.