This Old House Magazine: Magnificent Mahogany

For his own house, Norm splurged on mahogany for the interior and exterior trim around the windows and doors as well as the doors themselves in rooms where people linger most: the family room, kitchen, and four-season sunroom. "I knew it wouldn’t twist out of shape, and the windows will hold up to the weather." He left the inside trim natural, rubbing on three coats of Danish oil. That was eight years ago. "The inside looks richer than ever," he says, "and not a fleck of paint is coming off the outside."

True mahogany comes from three species of the genus Swietenia: mahagoni, humilis, and macrophylla. Although each has different leaves and flowers, their woods cannot be distinguished, even under a microscope, Wiedenhoeft says. These trees have buttressed bases that support a broad, leafy crown reaching up to 150 feet off the forest floor. Some specimens have been known to live for 350 years and acquire a girth of 6 feet in diameter, measured above the base. Because they require an abundance of sunlight, the seedlings take root and clump together in clearings where a fire, flood, or hurricane has torn an opening in the rain forest’s dense canopy. Any number of the winged, wind-born seeds can sprout in these clearings, but generally only one tree manages to reach the canopy before the dense shade "suffocates" any competitors, including the smaller mahogany trees in the same clump. As a result, it's common to find only one mature mahogany tree in every 2 acres of forest.

When there's a strong demand for the wood of a relatively few slow-growing trees, overharvesting is the lamentable result. The mahogany Cortez’s shipwrights coveted, Swietenia mahagoni—commonly known as Cuban, Jamaican, West Indian, or simply Caribbean mahogany—fell victim to lumber exporters. This species is no longer commercially logged (although plantation-grown wood is available). Neither is Swietenia humilis, or Pacific mahogany, a tree found in Central and South America that yields far less desirable wood. Only Swietenia macrophylla—Honduran or big-leaf mahogany, which grows from Mexico to Brazil—is still harvested from its indigenous forests. However, the Convention on International Trade in Endangered Species (CITES) lists Honduran mahogany as a tree at risk of being overexploited, and they require each shipment of the wood to be accompanied by export permits and documentation stating the country of origin. Honduran mahogany today retails for $6 to $8 per board foot in the U.S. (about the same as American walnut), roughly 25 percent more than 10 years ago.

Because of the wood's value and popularity, lumber brokers in other parts of the world have bestowed the name "mahogany" on other species of reddish wood as a way to burnish their appeal. For example, Santos mahogany (Myroxylon balsamum), which grows from southern Mexico all the way down to Argentina, is a much denser and harder wood than Honduran mahogany and makes a poor choice for turning or carving. But because the wood is twice as hard as oak, it is good for flooring. (Swietenia is a bit softer than longleaf pine.) Santos retails for as little as $4 a board foot.

African mahogany generally refers to several different species of Khaya, a tree that grows throughout West Africa. Its reddish-brown wood is as dense and stable as true mahogany (they are in the same family) and has a beautiful ribbon figure when sawn. But because it's more fibrous, Khaya doesn’t carve as easily. Even so, African mahogany is often used for furniture, cabinetry, interior trim, and decorative veneers. It retails for $5.50 a board foot.

Philippine mahogany is the name given to some of the different species of Shorea that grow throughout the Philippine archipelago as well as in Malaysia and Indonesia. These woods, which are also known as meranti or lauan, generally find their way into the U.S. market as inexpensive plywood. The dark red meranti is the closest in appearance to true mahogany, although it has a coarser texture, less stability, and only moderate rot resistance. Because of its hardness, durability, and relatively low retail price (about $4.95 a board foot), it's often used for exterior doors, windows, and decking. Yellow meranti, its far less durable cousin, is also sold as mahogany but is mainly used in plywood and paneling.

Despite the availability of these less expensive substitutes, demand for Honduran mahogany continues unabated, sustaining the pressure to log it wherever it can be found. Buyers who want this wood but are concerned about the effect that indiscriminate logging has on the species (as well as on the surrounding forests) have a couple of choices: They can seek out lumber cut from certified forests or purchase wood grown on plantations.

In forests certified as well-managed by the nonprofit Forest Stewardship Council, owners divide their land into blocks and agree to harvest only mature mahogany trees on only one block each year, and to not return to the first block until all the others have been harvested. Because each forest is different, the FSC works with individuals on a case-by-case basis. One example in South America has loggers working with 250-acre blocks in cycles that can take 40 to 60 years. They might only cut down 100 trees in a block. The idea is to give younger trees time to grow to a more marketable size, typically 30 inches in diameter. Annual follow-up inspections by the FSC ensure that the agreed-upon practices are being followed. Once a tree is felled, the lumber goes to FSC-certified importers in the U.S., who ship it to certified retailers where the price is about $1.50 a board foot higher than noncertified mahogany.

But according to Laura Snook, program leader for sustainable forest management at the Center for International Forestry Research, the long-term success of these operations depends on how often and how many trees are cut. "The cutting cycles in these managed forests are still arbitrary," she says. "They have no relation to the growing rate of the tree."

Faced with these difficulties, growing mahogany on plantations seems a logical solution. The Dutch started the first such plantations in Indonesia more than 100 years ago, after the supply of Cuban mahogany petered out in the Caribbean. Others have since been planted in Central and South America. But these tree farms packed the naturally isolated trees into tightly spaced stands, leaving them vulnerable to shoot-borer caterpillars, which feast on new shoots. The insects have the same effect as pruning, causing the seedlings to form multiple stems and become more bush than tree. Plantations outside mahogany’s natural range, mostly in Indonesia and Fiji, have been free of shoot-borer so far, but if the trees are cut before they mature, the wood lacks the density, color, and figure of forest-grown lumber. Plantation-grown Honduran mahogany is rarely stocked now, although growers in Indonesia are exporting hand-carved furniture from the wood grown on Javan tree farms.

Norm's solution to the shortage of true mahogany is to use the wood judiciously. "Sure, it would have been nice to use mahogany casings everywhere in my house," he says. "Instead, I used it where it would be most appreciated and where its durability is an asset. Mahogany deserves to be treated like the jewel it is."

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Swietenia macrophylla (commonly known as big-leaf or Honduran mahogany)
?Growing conditions: partial shade to full sun; prefers moist soil at low elevations from Mexico and
Florida to Brazil and Bolivia
?Maturing age: 40–60 years (approximately)
?Height when mature: 80–150 feet
?Maximum trunk diameter: 3–6 feet
?Maximum crown diameter: 60 or more feet
?Wood color: varies from pinkish-brown to amber and
reddish-brown
?Hardness Index (Janka): 800 (yellow pine, 690;
longleaf pine, 870; red oak, 1290)
?Durability: resistant to rot fungus and moderately
resistant to dry-wood termites
—Reported by Scott Schilling