Southern magnolia (Magnolia grandiflora) in numbers: hardness, weight, strength, shrinkage, movement and decay resistance, taken from the tables of the USDA Forest Products Laboratory’s Wood Handbook, followed by what the wood is like to work and what it is used for. The values are averages from small, clear, straight-grained test specimens; real boards with knots, sloping grain or a different moisture content will differ.
| Property | Southern magnolia |
|---|---|
| Janka side hardness, 12% moisture | 1,020 lbf (4,537 N) |
| Janka side hardness, green | 740 lbf |
| Hardness rank | harder than 89 of the 168 woods with a 12% hardness value in our database |
| Density at 12% moisture | 35.0 lb/ft³ (560 kg/m³) |
| Weight per board foot (12%) | 2.91 lb |
| Specific gravity (ovendry weight, green volume) | 0.46 |
| Specific gravity at 12% moisture | 0.50 |
| Bending strength (modulus of rupture), 12% | 11,200 psi |
| Stiffness (modulus of elasticity), 12% | 1.4 million psi |
| Crushing strength (compression parallel to grain), 12% | 5,460 psi |
| Shrinkage green to ovendry: radial / tangential / volumetric | 5.4% / 6.6% / 12.3% |
| Tangential / radial shrinkage ratio | 1.22 |
| Dimensional change per 1% moisture (radial / tangential) | 0.00187 / 0.0023 |
| Impact bending (drop height to failure), 12% | 29 in. |
| Heartwood decay resistance | slightly or nonresistant |
The species in this group
Lumber is often sold under a group name. These are the species the Wood Handbook reports for this group, with the same properties side by side.
| Species | Janka (lbf) | Density (lb/ft³) | Bending (psi) | Stiffness (Mpsi) | Crushing (psi) | Shrink T/R (%) | Decay resistance |
|---|---|---|---|---|---|---|---|
| Southern magnolia Magnolia grandiflora | 1,020 | 35.0 | 11,200 | 1.4 | 5,460 | 6.6 / 5.4 | slightly or nonresistant |
| Cucumbertree Magnolia acuminata | 700 | 33.6 | 12,300 | 1.82 | 6,310 | 8.8 / 5.2 | slightly or nonresistant |
What it is
Commercial magnolia is three species: southern magnolia (Magnolia grandiflora), also called evergreen magnolia, big laurel and bull bay; sweetbay (M. virginiana), sometimes called swamp magnolia; and cucumbertree (M. acuminata). The lumber of all three is sold simply as magnolia. Southern magnolia grows from North Carolina to Texas, sweetbay along the Atlantic and Gulf Coasts from Long Island to Texas, and cucumbertree from the Appalachians to the Ozarks and north to Ohio. Louisiana leads in magnolia lumber production.
Southern magnolia sapwood is yellowish white, and the heartwood is light to dark brown with a tinge of yellow or green. The wood has a close, uniform texture, is generally straight grained and closely resembles yellow-poplar. Cucumbertree wood is also similar to yellow-poplar, and cucumbertree growing within the yellow-poplar range is not separated from it on the market.
Working properties
Southern magnolia is moderately heavy, moderately low in shrinkage (6.6% tangentially from green to ovendry), moderately low in bending and compressive strength, moderately hard and stiff, and moderately high in shock resistance. Sweetbay is much like southern magnolia.
Weight and density
At 12% moisture content southern magnolia weighs about 35.0 lb per cubic foot, so one board foot (144 cubic inches) weighs about 2.91 lb. An 8 ft board of actual size 3/4 × 5-1/2 in. (a 1×6) holds 0.229 cubic feet and weighs about 8.0 lb; an 8 ft piece 1-1/2 × 3-1/2 in. (a 2×4 size) weighs about 10.2 lb. Green wood is much heavier because of the water it holds.
Density here is ovendry weight plus 12% water, divided by volume at 12% moisture content (Wood Handbook Eq. 4-12: density = specific gravity at 12% × 62.43 lb/ft³ × 1.12).
Wood movement
The Wood Handbook gives dimensional change coefficients for each species: the fraction of its width a board gains or loses for every 1% change in moisture content, between about 6% and 14%. For southern magnolia they are 0.0023 across a flatsawn face (tangential) and 0.00187 across a quartersawn face (radial).
Worked example: a flatsawn board 7-1/4 in. wide (a nominal 1×8) that goes from 6% moisture content in a heated winter house to 12% in a humid summer changes width by 7.25 × 0.0023 × 6 = 0.1 in. (about 3/32 in.). The same board quartersawn moves 0.081 in. (about 3/32 in.). Allow for this in panels, tabletops and floors; the wood movement calculator works it out for any size and moisture range.
How it compares
| Species | Janka (lbf) | Density (lb/ft³) | Bending (psi) | Stiffness (Mpsi) | Tangential shrink (%) | Decay resistance |
|---|---|---|---|---|---|---|
| Southern magnolia | 1,020 | 35.0 | 11,200 | 1.4 | 6.6 | slightly or nonresistant |
| Yellow-poplar | 540 | 29.4 | 10,100 | 1.58 | 8.2 | slightly or nonresistant |
| Black cherry | 950 | 35.0 | 12,300 | 1.49 | 7.1 | moderately resistant |
| Red maple | 950 | 37.8 | 13,400 | 1.64 | 8.2 | slightly or nonresistant |
| Sweetgum | 850 | 36.4 | 12,500 | 1.64 | 10.2 | slightly or nonresistant |
| American basswood | 410 | 25.9 | 8,700 | 1.46 | 9.3 | slightly or nonresistant |
Uses
Furniture, boxes, pallets, venetian blinds, sashes, doors, veneer and millwork.
Frequently asked questions
How hard is magnolia?
Southern magnolia averages 1,020 lbf (4,537 N) on the Janka test at 12% moisture content and 740 lbf green. Cucumbertree is softer at 700 lbf.
Is magnolia the same as poplar?
No, but it is close. The Handbook says southern magnolia closely resembles yellow-poplar, and cucumbertree growing within the yellow-poplar range is sold with it. Southern magnolia is the harder of the two (see the comparison table).
Is magnolia stable?
The Handbook rates southern magnolia as moderately low in shrinkage: 6.6% tangentially from green to ovendry. In service a flatsawn board changes width by about 0.23% for each 1% change in moisture content.
Can magnolia be used outdoors?
Not untreated. Magnolia heartwood is in the slightly or nonresistant decay class, so it needs preservative treatment or a protected location outdoors.
Sources
- USDA Forest Products Laboratory. Wood Handbook: Wood as an Engineering Material. General Technical Report FPL-GTR-190, 2010. Chapter 2 (species descriptions), Chapter 4 (Tables 4-3, 4-4 shrinkage; Eq. 4-7, 4-9, 4-12 density), Chapter 5 (Tables 5-3b, 5-5b strength and hardness), Chapter 13 (Table 13-5 dimensional change coefficients), Chapter 14 (Table 14-1 decay resistance)
- USDA Forest Products Laboratory. Wood Handbook, 2021 edition (FPL-GTR-282)
Last reviewed: 24 October 2026. Numbers are generated from our parsed copy of the Handbook tables, so every page uses the same data. Values marked * are estimates computed with the Handbook’s own equations. Spotted an error? Please let us know.