The lily magnolia (Magnolia lililflora) is a large deciduous shrub (or small tree) that sports profuse pink or reddish-purple blossoms in April and early May, just before the leaves appear. As one of the smaller magnolias, it is popular for informal screens or hedges and as a specimen plant grown for its spring flower display.
Lily magnolia grows to a mature height of 8 to 12 feet with a similar spread. It has a compact, rounded form and produces a massive display of lily-shaped pink or reddish-purple flowers with six or seven petals, with each petal 3 to 4 inches long. The flowers are sometimes followed by cone-shaped purple or brown fruit, called follicles. As with other magnolia species, pollination is facilitated by beetles. The shrub's dark green elliptical-shaped leaves appear as its flowers fade. Its fall foliage is not showy.
|Botanical Name||Magnolia liliflora|
|Common Name||Lily magnolia, Japanese magnolia, Mulan magnolia|
|Plant Type||Deciduous flowering shrub|
|Mature Size||8 to 12 feet tall with a similar spread|
|Sun Exposure||Full sun to part sun|
|Soil Type||Rich, well-drained|
|Soil pH||5.8 to 6.8 (acidic)|
|Hardiness Zones||5 to 10 (USDA), depending on variety|
|Native Area||China, Japan|
How to Grow Lily Magnolia
Plant lily magnolia shrubs in a full-sun to part-shade location with rich, moist, slightly acidic soil. This is not a plant that tolerates poor soil. Try to position it where it will be protected from strong wind and the coldest winter temperatures. But don't plant it next to the home, where artificial warmth may cause the buds to open too early in the spring.
Lily magnolia is a somewhat temperamental shrub when it comes to garden conditions, preferring ideal soil and consistent, regular moisture throughout the year. Mulching the root zone will help moderate soil temperatures and moisture levels. Prolonged drought may kill this shrub.
For best flowering, lily magnolia requires a site with full sun, though it also grows adequately in part shade.
The plant does best in moist, rich soils that are slightly acidic and well-drained. Heavy soils should be amended with peat moss or compost before planting.
Water the shrub regularly throughout the year for the first few years, and cover the root zone with mulch to balance out soil moisture levels and temperatures. Once established, lily magnolia is moderately tolerant of temporary dry conditions, but pamper it during prolonged droughts.
Temperature and Humidity
Lily magnolia is best planted in a semi-sheltered area that is protected from strong winds and cold temperatures. Also, avoid southern exposures where the buds may open too early in spring. Don't attempt to stretch the zone 5 to 9 hardiness range recommendation; even the northern part of zone 5 can sometimes be borderline for this plant, with spring flowers easily killed off by early spring cold spells.
Lily magnolias do not need fertilizer when they are planted. Afterward, they benefit from a spring feeding of slow-release fertilizer, applied as the flower buds begin to develop.
Magnolias generally do not respond well to severe pruning, but when the shrub becomes overgrown or when there are dead or damaged branches, prune it immediately after it flowers. If you prune too late, it will reduce flowering the following spring.
Propagating Lily Magnolia
You can propagate this magnolia by taking cuttings or planting the seeds. If you have planted a hybrid variety, the plants resulting from the seeds may be different from the parent plant.
To propagate from cuttings, use a sterilized pruner to take 6- to 8-inch cuttings in early summer after the buds have set. Take the cuttings from growing tips of the branches, then remove all but the upper leaves. Make a 2-inch vertical slice in the end of the stem, then dip the cut end in rooting hormone. Plant the cuttings in small containers filled with moist perlite.
Place the container in a loose plastic bag and set it in a bright location out of direct sunlight. Keep the cuttings moist and grow them in the containers for several months until a good root network has developed. They can then be transplanted into the garden in fall.
Varieties of Lily Magnolia
- Magnolia lilliflora 'Nigra': This variety has darker purple flowers than the species form; it is suitable for zones 5 to 9.
- M. lilliflora ‘O'Neil’: Growing to 15 feet with dark purple flowers, this variety is well suited for zones 6 to 9.
- M. lilliflora 'Gracilis': This variety has a narrower growth habit and narrower leaves than other varieties; it is suitable for zones 5 to 9.
In addition to these popular cultivars, 'Nigra' is often crossed with other Magnolia species to produce new hybrids. For example, the U.S. National Arboretum created eight different varieties by crossing 'Nigra' with Magnolia stellata 'Rosea.' They are collectively called "The Girls" since they were given female names: 'Ann,' 'Betty,' 'Jane,' 'Judy,' 'Pinkie,' 'Randy', 'Ricki,' and 'Susan.'
Another is 'Star Wars,' a hybrid of M. campbellii and M. liliiflora, with large, rosy-pink flowers up to 11 inches across.
Common Pests/ Diseases
Lily magnolia is a relatively problem-free shrub, and those problems that do occur are rarely life-threatening.
- Magnolia scale insects (Neolecanium cornuparvum) suck out sap from the stems. Encourage ladybugs to visit your garden, as they will snack on the scales and help remedy the problem to some degree. Horticultural and dormant oils can be used at different stages in the life cycle, though they will not be so effective against adults that have formed a wax barrier on their bodies.
- Black sooty mold can form on plants that are infested with the magnolia scale. They drop a sugary substance called honeydew that the mold grows on. Control the scale insects to help prevent mold.
- Powdery mildew is another fungal problem that can crop up, especially in humid conditions, but it rarely kills the plant. To reduce powdery mildew, prune to improve air circulation. Keep the area around the tree free of debris. Spraying the shrub with water early in the day may help dislodge mold spores. Fungicides applied early in the season can also prevent mildew.
Lily magnolia is most often grown as a specimen or accent plant in sunny areas. It's also good for group plantings or as an informal hedge or screen. It is moderately drought-tolerant once the roots have had a chance to firmly anchor themselves after several years.