Several wood species naturally resist termites, including cedar, redwood, teak, cypress, and tropical hardwoods like ipe and cumaru. The key factor is the heartwood: the dense, chemically rich inner wood of the tree. Sapwood from the same tree can be completely vulnerable, so knowing which part of the lumber you’re buying matters as much as the species itself.
North American Species With Natural Resistance
If you’re shopping at a local lumberyard in the U.S. or Canada, these are the termite-resistant species you’re most likely to find.
Western red cedar is one of the most widely available options. Its heartwood contains natural oils and phenolic compounds that deter termite feeding. In USDA Forest Service testing, western red cedar heartwood was classified as unfavorable to termite feeding and survival. Port Orford cedar scored even higher, earning a “very resistant” rating (the top tier on the 1-to-4 durability scale used by Oregon State University’s Forest Research Laboratory).
Redwood (specifically California redwood, or Sequoia sempervirens) performs similarly well. Its dark heartwood resists both decay and termites, making it a popular choice for decks, fencing, and outdoor structures in the western U.S. Like cedar, its lighter-colored sapwood offers little to no protection.
Baldcypress is the go-to termite-resistant softwood in the southeastern U.S., where subterranean termites are most aggressive. Heartwood of old-growth baldcypress is exceptionally durable, though younger, farm-grown trees produce less heartwood and correspondingly less resistance.
Eastern red cedar (Juniperus virginiana) rounds out the domestic options. It tested as unfavorable for termite feeding in the same USDA study. It’s a smaller-dimension wood, so it’s more practical for closet linings, chests, and trim than for structural framing.
Tropical Hardwoods: The Premium Tier
Tropical hardwoods sit at the top of the termite-resistance spectrum, combining extreme density with high concentrations of natural oils. The tradeoff is cost: these woods are imported, heavy, and harder to work with standard tools.
Ipe (Brazilian walnut) is arguably the gold standard. With a Janka hardness rating of 3,510 pounds, it’s so dense that termites essentially cannot feed on it. Its natural oils make it practically impervious to insects and rot. Ipe decking can last 25 years or more without chemical treatment.
Cumaru (Brazilian teak) is nearly as hard at 3,330 pounds on the Janka scale and offers comparable resistance. Jatoba (Brazilian cherry) comes in at 2,690 pounds. Both are used for decking and outdoor flooring in termite-prone regions.
Teak is the classic choice for marine and outdoor applications. At 1,070 pounds on the Janka scale, it’s not as hard as ipe, but its natural vegetable oils make it extremely resistant to water, termites, and other insects. Teak has been used in shipbuilding for centuries precisely because of this combination of properties.
Why Some Woods Resist and Others Don’t
Termite resistance comes down to chemistry, not just hardness. Wood naturally contains compounds like phenols, terpenes, essential oils, resins, and quinones, all of which can repel or kill termites. Research published in the Journal of Insect Science found that the higher the lignin and total phenolic content of a wood species, the greater its resistance to termite attack. Conversely, woods with high cellulose content (the main carbohydrate termites digest) are more susceptible.
The phenolic content across tested species ranged from 271 mg per 100 g in European beech (highly susceptible) to 768 mg per 100 g in certain Indonesian hardwoods (highly resistant). That nearly threefold difference in chemical concentration explains why some lumber gets destroyed in months while other species last decades.
Heartwood vs. Sapwood: A Critical Distinction
No species is termite-resistant throughout the entire cross-section of the tree. The protective chemicals are deposited during heartwood formation, the natural process where the inner core of the trunk becomes denser and darker as the tree ages. Sapwood, the lighter outer ring that actively transports water in a living tree, lacks these deposits.
The difference is dramatic. In laboratory testing, termites survived on sapwood but died on heartwood cut from the same tree. USDA researchers also found that resistance varies by position within the trunk: wood closer to the center and lower in the tree tends to be more resistant than wood near the outer rings or from higher up.
When buying “termite-resistant” lumber, look for boards that are predominantly heartwood. If a cedar or redwood board has a thick band of pale sapwood along one edge, that edge is just as vulnerable as pine.
What About Bamboo?
Bamboo is sometimes marketed as a termite-resistant alternative, and there’s partial truth to this. The outer layer of bamboo culms contains significant amounts of silica, which acts as a digestibility reducer. In termite testing, researchers observed that termites consistently invaded bamboo from the cut ends and inner surfaces rather than penetrating the silica-rich exterior.
That said, bamboo is not uniformly resistant. The inner layers are vulnerable, and once termites access the softer interior tissue, they feed readily. Bamboo used in construction typically needs chemical treatment for reliable long-term protection in termite-prone areas.
Choosing the Right Wood for Your Project
Your best choice depends on what you’re building and where it sits relative to the ground. Ground contact is the harshest exposure: soil moisture attracts subterranean termites, and even naturally resistant heartwood degrades faster when buried. Untreated, non-resistant wood in ground contact may last only 2 to 5 years in warm climates. Naturally resistant heartwood performs far better, but no untreated wood is truly permanent in soil.
- Decking, fencing, and outdoor furniture: Cedar, redwood, and teak are practical choices that balance cost, workability, and resistance. Ipe and cumaru are more expensive but last significantly longer.
- Structural framing near or in the ground: Tropical hardwoods like ipe offer the best untreated performance. For domestic species, pressure-treated lumber is generally more reliable than relying on natural resistance alone for ground-contact structural members.
- Interior trim and storage: Eastern red cedar is a classic for closets and chests. Its aromatic oils repel insects in enclosed spaces.
Keep in mind that “termite resistant” does not mean “termite proof.” Even the most resistant species can eventually be damaged under sustained pressure from large termite colonies, especially if the wood stays damp. Proper drainage, ventilation, and keeping wood away from direct soil contact all extend the life of any lumber, resistant or not.