How to Grow Southern Magnolia
Magnolia grandiflora
Southern magnolia is a large evergreen tree with glossy dark green leaves and spectacular fragrant white flowers up to 30cm across. Plant in moist, well-drained, slightly acidic soil in full sun to partial shade. Shelter from cold winds in cooler climates; wall training works well in borderline areas. Water regularly until established. Minimal pruning needed. Drops old leaves year-round rather than seasonally.
Yearly Lifecycle
Care Essentials
Apply a slow-release balanced fertilizer in early spring. Mulch with acidic compost or leaf mould annually.
Watch For
- Scale insects
- Algal leaf spot
- Sooty mould from honeydew
Companions
Camellias, Azaleas, Ferns, Hostas
Pet Safety
Care Requirements
Light
Full sun to partial shade
Thrives in full sun but tolerates partial shade. In cooler climates, a warm south or west-facing wall provides ideal shelter and heat retention.
Watering
Regular watering for young trees
Water deeply and regularly during dry spells for the first 3-5 years until established. Mature trees are moderately drought-tolerant once their deep root system develops.
Fertilizing
Annual mulch with acidic compost
Apply slow-release balanced fertilizer in early spring. Mulch annually with acidic compost or leaf mould. Prefers slightly acidic soil; chlorosis can develop on alkaline soils.
Pruning
Minimal; prune after flowering in summer
Requires very little pruning. Remove dead, damaged, or crossing branches after flowering in mid-summer. Tolerates hard renovation pruning if necessary but recovers slowly.
Spacing
8-10m from structures and other trees
A large tree reaching 15-25m tall with a spread of 8-12m. Allow ample space for the wide canopy. Can be wall-trained in restricted spaces.
Support
Stake young trees for 2-3 years
Stake newly planted trees with a low stake for the first 2-3 years until the root system anchors firmly. Remove stakes once the trunk can support the canopy independently.
Growing Tips
Leaf drop is normal
Evergreen but drops old leaves year-round. This is normal, not a sign of stress. Rake fallen leaves or leave as mulch.
Protect young trees from cold
Young trees are vulnerable to cold. Plant in a sheltered spot or against a warm wall. Protect with fleece in harsh winters for the first few years.
Do not disturb roots
Avoid disturbing roots once planted. Magnolias resent root disturbance and are slow to re-establish. Mulch rather than cultivating.
