Black Tupelo (Blackgum)
Nyssa sylvatica · hardwood · Eastern North America · moderate movement
- Janka hardness 810 lbfred oak ≈ 1,290 lbf
- Density ≈ 35 lb/ft³specific gravity 0.5 at 12% MC
- Shrinkage — tangential 8.7%flatsawn width, green → ovendry
- Shrinkage — radial 5.1%quartersawn width
- T/R ratio 1.7 : 1higher = more cupping in flatsawn stock
Shop notes Interlocked grain that will not split — mallet heads and cutting boards. Plane with sharp irons and expect some tearout anyway.
Seasonal movement at a glance
Width change for black tupelo (blackgum) across a typical indoor year — 6% moisture content in the heated winter to 12% in a humid summer:
| Board width | Flatsawn | Quartersawn |
|---|---|---|
| 6″ | 1/8″ (0.112″) | 1/16″ (0.066″) |
| 12″ | 7/32″ (0.224″) | 1/8″ (0.131″) |
| 24″ | 7/16″ (0.447″) | 1/4″ (0.262″) |
| 36″ | 21/32″ (0.671″) | 13/32″ (0.393″) |
Run your own numbers
Different width, different climate swing — the calculator below is preset to black tupelo (blackgum):
Typical swings:
Black Tupelo (Blackgum) questions
How much does black tupelo (blackgum) move with the seasons?
A 12″-wide flatsawn black tupelo (blackgum) board moves about 7/32″ across a typical indoor swing from 6% to 12% moisture content; quartersawn, about 1/8″. Its tangential shrinkage is 8.7% and radial 5.1% (green to ovendry) — a moderate-movement wood.
How hard is black tupelo (blackgum)?
Black Tupelo (Blackgum) rates about 810 lbf on the Janka scale — softer than red oak but sturdy (red oak is roughly 1,290 lbf). Density runs about 35 lb/ft³ at indoor moisture levels.
Is black tupelo (blackgum) good for wide panels and tabletops?
Yes, with normal precautions: its 1.7:1 tangential-to-radial ratio is moderate. Still fasten solid tops so they can move across their width.
Similar species
Honduran Mahogany · American Elm · Black Ash · Bigleaf Maple · Sweetgum · American Sycamore
Shrinkage, specific gravity, and hardness from the Wood Handbook, FPL-GTR-282 (2021 edition), USDA Forest Products Laboratory (public domain). Values are species averages — individual boards vary with growth conditions and how they were dried.