Southern magnolia
Sources last read 14 September 2026.
Middling It gives warning, with time to act.
Also called Big-laurel, bull bay, bullbay, Evergreen Magnolia, great laurel-leaved magnolia, Large Tree Magnolia, large-flowered magnolia, laurel magnolia and loblolly magnolia.
Toxicity is partly unassessed
- Not assessed for cats. This plant is not on the ASPCA list. That is not a finding of safety: none of the sources read for this site gives an answer either way. Treat it as unknown.
- Not assessed for dogs. This plant is not on the ASPCA list. That is not a finding of safety: none of the sources read for this site gives an answer either way. Treat it as unknown.
- Not assessed for people. RHS publishes no harm statement for this plant. That is not a finding of safety: none of the sources read for this site gives an answer either way. Treat it as unknown.
What the sources say about its care
- Light
- Full sun, Partial shadeRHS · read 13 September 2026
- Water
- Moist but well-drained or Well-drainedRHS · read 13 September 2026
- Humidity
No source read publishes a humidity figure for any plant on this site. What follows is general guidance for foliage plants.
ASHRAE recommends indoor relative humidity between 30% and 60% 30–60%Penn State Extension · read 13 September 2026- Temperature
How cold this tolerates, not what it prefers. No source read for this site publishes a preferred range for a plant indoors.
H5 — -15 to -10°C -15 to -10 °CRHS · read 13 September 2026- Soil
- Chalk, Clay, Loam, Sand; pH Acid or Alkaline or NeutralRHS · read 13 September 2026
- Toxic to cats
- Not on the ASPCA list. That is not a finding of safety.ASPCA · read 13 September 2026
- Toxic to dogs
- Not on the ASPCA list. That is not a finding of safety.ASPCA · read 13 September 2026
- Harmful to people
- No statement of harm to people is published for this plant; that absence is not evidence it is safe.RHS · read 13 September 2026
How it usually goes wrong
- A thin dry rim that crumbles between the fingers
Tips first on a southern magnolia, then margins. Affected tissue is papery and slightly curled, and the damage stops rather than advancing once conditions change.
Penn State Extension notes that most indoor plants benefit from more humidity than a home heated in winter provides. The leaf edge, furthest from the veins, is where the shortfall shows. That applies while it is grown indoors; its RHS rating of H5 describes a plant that also grows outside, where the air is seldom that dry.
Telling it apart: Where the plant stands. Browning concentrated on the side facing a heater points at the air.
Penn State ExtensionDiagnose leggy growth on this Southern magnolia- Dry, bruised edges after a cold, windy spell
The damage on the southern magnolia is one-sided and appeared all at once: browned margins, splits and bruised leaves facing the prevailing wind, while the sheltered side is clean.
RHS describes it as needing shelter. Moving air dries leaf surfaces quickly and bruises soft tissue, so a canopy in a windy spot is marked on the side the wind reaches.
Telling it apart: Whether it followed stormy weather. Damage that appeared overnight after wind is weather; damage that develops over weeks is something else.
RHSDiagnose brown tips and edges on this Southern magnolia- Faded, yellow-white areas on the sunny side of the canopy
The damage on the southern magnolia faces one way. Turn the pot round and the other side is clean.
Even a plant described as full sun, partial shade can take more through glass than it would outdoors, because glass removes the breeze that carried the heat away.
Telling it apart: The edge of the damage. Scorch has a sharp boundary; rot and infection have a soft, spreading one.
RHSSouthern magnolia leaves turning yellow: causes- Yellow, limp leaves at the base
The lowest leaves of the southern magnolia go yellow and translucent at the stalk and drop with a light pull, while the compost stays wet.
Soil described as moist but well-drained or well-drained is a drainage instruction as much as a watering one. Compost that stays saturated suffocates the fine roots that do the drinking.
Telling it apart: The soil, not the leaf. Wet compost under yellowing leaves points one way and dry compost the other, and the leaves alone will not tell you which.
RHSSouthern magnolia leaves turning yellow: causes
Not sure which it is? Ask the diagnosis questions for Southern magnolia.
Routine care
- Propagation
- SeedNC State Extension · read 13 September 2026Root semi-ripe cuttings between late summer and early autumn, or layer in early spring.RHS · read 13 September 2026
- Pruning
- Lower branches often touch the ground; removing them gives a more tree-like look.NC State Extension · read 13 September 2026Pruning group 9, or group 13 when wall-trained; see magnolia pruning.RHS · read 13 September 2026
- Pests and diseases
- Can be troubled by magnolia scale and yellow poplar weevil. Diseases: sooty molds.NC State Extension · read 13 September 2026Capsid bug, horse chestnut scale and scale insects can attack it. Disease risks: fungal leaf spot, a virus, honey fungus, grey moulds, Phytophthora or coral spot.RHS · read 13 September 2026
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Photographs
About the plant
Magnolia grandiflora, commonly known as the southern magnolia or bull bay, is a flowering tree in the family Magnoliaceae native to the Southeastern United States coastal plain, from Virginia to central Florida, and west to East Texas. Reaching 27.5 m (90 ft) in height, it is a large, striking evergreen tree, with large, dark-green leaves up to 20 cm long and 12 cm wide, and large, white, fragrant flowers up to 30 cm (12 in) in diameter.
From Wikipedia, CC BY-SA 4.0 · read 13 September 2026
- Native range
- SE. U.S.A. to TexasWorld Checklist of Vascular Plants, June 2026 release, CC BY.Kew WCVP · read 13 September 2026Southeastern United StatesNC State Extension · read 13 September 2026SE USARHS · read 13 September 2026
- Climate
- subtropicalWorld Checklist of Vascular Plants, June 2026 release, CC BY.Kew WCVP · read 13 September 2026
- Growth form
- Perennial, Tree; habit conical, dense, pyramidalNC State Extension · read 13 September 2026Bushy (evergreen)RHS · read 13 September 2026
- Size
- Height 720–960 in; width 360–600 inNC State Extension · read 13 September 2026Height Higher than 12 metres; spread wider than 8 metres after 20–50 yearsRHS · read 13 September 2026
- Flowering
- Flowers cream/tan, white; blooms in spring, summerNC State Extension · read 13 September 2026Flowers cream in summer and autumn; white in summer and autumnRHS · read 13 September 2026
- Uses
What sources record people using this plant for. A traditional or medicinal use listed here is a record of use, not advice to eat it or treat anything with it.
Traditionally it was a medicine for circulatory disorders. Extracts from the leaves, fruit, bark and wood may have pharmaceutical uses. Its wood is soft, light and tan, with a faint grain, and has commercial uses in veneer, paper pulp, furniture parts, and flake and chip board.NC State Extension · read 13 September 2026
Common problems with Southern magnolia
Plants with similar care
AvocadoDry scorched spots after a move into a sunnier spot
Chinese banyanFaded, yellow-white areas on the sunny side of the canopy
Coffee plantLeaf tips go crisp and brown
Crape myrtleCrisp margins that appear in winter
Japanese mapleDry, curled edges on leaves near a heater
Norfolk Island pineBleached patches on the side facing the glass
Sources
- ASPCA · read 13 September 2026
- Kew WCVP · read 13 September 2026
- NC State Extension · read 13 September 2026
- Penn State Extension · read 13 September 2026
- RHS · read 13 September 2026
- Wikipedia · read 13 September 2026
What this does not cover
The figures above are what published sources say, not measurements of the plant in your room. They say nothing about your pot size, your water, the season, or how far from the glass the plant stands, and those decide more than any figure here does.
Humidity has no species figure because no source read for this site publishes one, and the only temperature published for this plant is a cold floor. The simulator fills those gaps with general figures for its kind of plant, marked as general and listed on how we read sources. Where a toxicity row says the plant was not assessed, that is the absence of a finding and not a finding of safety.
If something is already wrong, the diagnosis tool asks about the soil, the window and the watering, which is where the answer usually is.