Tigerwood is one of the most visually distinctive hardwoods in the outdoor lumber market. Its bold, irregular grain — dark brown or black streaks cutting across a reddish-amber base — earns the name immediately. Beyond aesthetics, tigerwood is a serious performer in outdoor applications, combining hardness and natural decay resistance that most domestic softwoods cannot approach.
Understanding tigerwood's physical properties, where it is harvested, and how it behaves outdoors helps buyers evaluate whether the investment is the right fit for a specific project — deck, raised bed, garden furniture, or outdoor structure.
What Is Tigerwood?
Tigerwood (Astronium graveolens, also sold as Astronium fraxinifolium depending on origin) is a tropical hardwood native to Central and South America, with the majority of commercial supply coming from Brazil. The species goes by several trade names — Brazilian tigerwood, goncalo alves, zorrowood, and muiracatiara — that vary by exporter and market. In the United States, "tigerwood" is the dominant retail name for this species in decking and flooring applications.
It is not a single botanical species but a small group of closely related Astronium species that share similar properties. Buyers should confirm that the scientific name matches Astronium graveolens or A. fraxinifolium when purchasing from international suppliers — other woods are sometimes sold under the tigerwood name in different regions.
Physical Properties
Tigerwood is genuinely hard. It registers approximately 1,850 lbf on the Janka hardness scale — harder than white oak (1,360 lbf) and approximately 50 percent harder than pressure-treated southern yellow pine (1,225 lbf). This hardness translates directly into surface durability: tigerwood decking and flooring resists denting, scratching, and wear under heavy foot traffic far better than any domestic softwood species.
Density averages around 58–62 pounds per cubic foot, comparable to other tropical hardwoods in its class. The wood is tight-grained with a naturally low porosity that limits moisture penetration. This tight cellular structure is responsible for both its water resistance and its tendency to be somewhat difficult to work with conventional woodworking tools — slower feed rates and sharp carbide tooling are required.
Appearance and Grain Character
The defining characteristic of tigerwood is its figure. The base color runs from golden amber to reddish-brown. Dark chocolate or nearly black streaks follow the grain direction but vary in width and intensity from board to board and within individual boards. No two pieces are identical, and the variation is the appeal — tigerwood installed as decking or flooring has a natural pattern depth that no stain or manufactured composite can replicate.
The interlocked grain common in tigerwood creates a ribbon-like stripe effect when boards are quartersawn or when the milling angle intersects the interlocked cells at the right orientation. The surface texture is fine to medium, with a natural luster that responds well to oiling and finishing.
Natural Durability Outdoors
Tigerwood is rated Class 1 or Class 2 for natural durability depending on the testing methodology, meaning it resists fungal decay without chemical treatment. The heartwood contains natural extractives that inhibit mold, fungal growth, and wood-boring insects including termites. In outdoor applications with good drainage and air circulation, tigerwood reliably achieves 20–30 year service life with minimal maintenance.
For gardeners building sustainable raised beds where chemical-free wood is a priority, tigerwood's natural durability is a genuine advantage over pressure-treated alternatives. No copper compounds, no chromium — just dense, oil-rich wood performing on its own chemistry.
Outdoor Applications
Tigerwood is used most commonly as decking, where its hardness and visual drama create a high-end result. It also appears in outdoor furniture, pergola components, garden structures, planter boxes, and as accent material in mixed-wood projects. The dramatic grain makes it especially well-suited to applications where the wood surface is visible rather than painted or obscured.
In garden settings, tigerwood works for raised bed frames, bench seating, decorative borders, and container planters. Its performance in sustained soil contact is better than cedar but typically somewhat below Class 1 species like ipe and cumaru — a liner or elevation from grade contact improves long-term results in high-moisture applications. For above-grade uses, tigerwood is an excellent and distinctive choice. Those already evaluating hardwood options should compare it against the white oak and cedar comparison to understand the full range of outdoor wood alternatives.
Frequently Asked Questions
- Is tigerwood the same as goncalo alves?
- Yes. Goncalo alves is the traditional lumber trade name for Astronium graveolens and related species. Tigerwood is a more recent marketing name that emerged in the North American decking and flooring market. Both names refer to the same wood.
- How hard is tigerwood compared to ipe?
- Tigerwood scores approximately 1,850 lbf on the Janka scale. Ipe scores 3,510 lbf. Ipe is roughly twice as hard as tigerwood — a meaningful difference for high-traffic commercial applications, though tigerwood remains significantly harder than domestic softwoods and performs well for residential decks and garden structures.
- Does tigerwood need to be sealed outdoors?
- Tigerwood does not require a sealer to survive outdoors. Untreated, it will weather to a silver-gray patina within 12–18 months. Applying a penetrating oil or UV-stabilized finish preserves the original amber-and-stripe appearance and slows surface checking. Annual oiling is the standard maintenance recommendation for those who want to maintain the original color.
- Where is tigerwood harvested?
- The majority of commercial tigerwood supply comes from Brazil. Smaller volumes originate in Bolivia, Peru, Colombia, and parts of Central America. Look for Forest Stewardship Council (FSC) certification when purchasing to confirm legal, sustainably managed harvest.
- Is tigerwood safe for edible garden beds?
- Yes. Tigerwood is a naturally durable hardwood with no chemical preservatives. It does not leach harmful compounds into soil. It is a safe choice for raised vegetable beds, on par with cedar, black locust, and other naturally rot-resistant species.