Subabul Wood (Leucaena leucocephala): Properties, Density & Uses

What subabul is

Subabul is the timber of Leucaena leucocephala, a thornless leguminous tree in the family Fabaceae — the same broad family as the pulses and acacias.1 It carries a long list of botanical synonyms, most often Leucaena glauca, and an equally long list of common names: white leadtree, white popinac, horse tamarind and jumbay in English, and ipil-ipil, koa haole or tan-tan across South-East Asia.1 In India none of that matters at the timber yard, where it is known by a single word in every language — subabul.

The important thing for a buyer to understand is that subabul is a plantation and farm-forestry crop, not a forest hardwood. It is planted, grown fast, and cut on a short rotation, chiefly to feed paper mills and low-cost packing lines. That origin shapes everything about the wood: it is cheap, uniform, medium in weight, easy to work, and available in small sizes rather than wide boards.

Where it grows

The natural range is small — southern Mexico and the northern fringe of Central America, from the Yucatan peninsula through Belize and Guatemala.15 From that narrow homeland it has spread so thoroughly that it now grows wild across more than a hundred tropical countries, which is why it is best known globally not as a crop but as a weed (more on that below).7

In India subabul was taken up as a fast-growing plantation and social-forestry species and is grown at scale, above all as industrial pulpwood. The largest concentrations are in Andhra Pradesh and Telangana, on the black alkaline soils that suit it, with more in Karnataka, Tamil Nadu and Maharashtra. Paper companies build their raw-material supply around it — ITC alone draws subabul from tens of thousands of hectares of farmer plantations in its mill catchment, and short-rotation clone programmes run alongside eucalyptus and casuarina.6 An honest note for a Kerala buyer: subabul grows readily here too, but Kerala's plywood cluster runs on rubberwood, so subabul as a packing and core timber is mainly an Andhra–Telangana–Karnataka story rather than a local one.

Appearance and grain

Subabul is a plain, honest-looking wood. The heartwood is a light reddish-brown and the sapwood a pale yellow, without strong figure or contrast.2 The texture is medium and the grain close and generally straight, which is part of why it machines and peels cleanly.2 It is not a decorative timber — nobody specifies subabul for a show face — but that same evenness is an asset in a core veneer or a packing board that simply has to be flat, sound and consistent.

Weight, density and hardness

Density is where the published sources argue with each other, so it is worth being plain about it. Measured on specific gravity, subabul comes out at 0.45–0.55 in some references and 0.5–0.6 in others, with a five-year plantation figure around 0.52.235 Clonal density studies land in a similar band, roughly 495–608 kg/m³. Taken together, a sensible working figure for air-dry timber is about 500–650 kg/m³ — a medium-density hardwood, neither light nor heavy.

You will also see a "~800 kg/m³" figure quoted widely.24 That number is copied from source to source but is inconsistent with the specific-gravity data, and is best read as green (freshly felled) weight rather than seasoned density. We would not price or plan around it.

On hardness, the honest answer is that no species-specific Janka value has been published for subabul in the accessible literature. PROSEA notes only that the wood is "hard enough for flooring."3 A number could be estimated from the specific gravity, but we would rather state the gap than quote a figure that no one has actually measured. For its intended packing and core uses the density band above tells the buyer what they need: medium weight, fair strength, adequate for crates and pallets.

Working and seasoning

This is where subabul earns its keep. The wood is described as strong and hard for its weight yet easily worked; it saws cleanly, peels for veneer, and "turns well."34 Sawn timber, plywood, particleboard and even parquet all appear on the list of documented end-uses.36

Its stand-out practical virtue is seasoning: subabul "dries without splitting or checking" and shows low degrade on air-drying.24 For a packing operation that turns stock around quickly, wood that dries flat and stable without splitting is worth a great deal. The real limits are dimensional, not behavioural: logs are usually small (often under 30 cm), branchy and high in juvenile wood, so recovery of wide clear boards is poor.26 That is exactly why subabul is a workhorse for pulp, crating, pallet stock and ply core rather than furniture-grade planks. It nails and fastens acceptably for crating, though knotty short-rotation stock benefits from pre-boring near the ends.

Durability and treatment

Untreated, subabul is low in natural durability. Poles and sawn stock are non-durable and are readily attacked by termites and powder-post borers; the wood is not suited to untreated outdoor or ground-contact service.236

The compensating strength is that it treats extremely well. PROSEA records that it "accepts preservatives well," and boron (borax/boric-acid) steeping trials have given effective termite protection.3 In practice that means the low natural durability is easily engineered around: boron- or CCA-treated subabul crates and pallets give good service life and can be brought in line with fumigation and treatment norms for export packaging. For a packing buyer the message is simple — specify treated subabul, not raw, wherever the wood will see moisture, storage or overseas transit.

Sustainability and sourcing

Subabul is one of the rare timbers where sustainability is a genuine, uncomplicated selling point. It is not a threatened species — the opposite. It is formally listed among the "100 of the World's Worst Invasive Alien Species," forming dense thickets that are hard to eradicate.17 So buying subabul carries no endangered-species or forest-depletion concern at all.

Supply is overwhelmingly plantation and farm-forestry grown, not cut from natural forest. The tree grows 3–4 m a year, is harvestable in three to four years, and yields on the order of 10–60 m³ per hectare per year, with modern clones giving around 80 tonnes of pulpwood per hectare in four years.6 Being a nitrogen-fixing legume, it also improves the soil it grows on, fixing well over 500 kg of nitrogen per hectare a year.1 In short, it is a renewable, short-rotation, genuinely low-impact raw material — and its abundance is exactly why it is one of the cheapest domestic packing and pulp timbers available.

What subabul is used for

In India subabul's uses run, in order of tonnage, roughly as follows:

Pulpwood is the number-one use by a wide margin — it is a premier fast-growing feedstock for the paper industry, with a pulp yield around 50–52%, low lignin, and paper quality rated excellent.32 Packing cases, crates and pallets, and plywood core come next: medium density, easy sawing and peeling, low-degrade seasoning and excellent preservative uptake make subabul a natural low-cost workhorse for wooden packing cases, box and crate wood, pallet stock, and core veneer in commercial plywood and blockboard — used alongside or instead of eucalyptus and poplar.36 It is also a feedstock for particleboard, OSB and chipboard, a preferred fuelwood and charcoal (calorific value about 4,600 kcal/kg, roughly 19,250 kJ/kg bone-dry, burning steadily with under 1% ash), and, beyond timber altogether, a high-protein cattle fodder and green manure.231

How Cochin Wood uses subabul

We should be straight about this. Cochin Wood Industries is a Kerala manufacturer, and our own packing and plywood work is built primarily on rubberwood, the timber our region grows in volume. Subabul is not a Kerala staple — it is chiefly an Andhra, Telangana and Karnataka plantation wood. Where it earns a place in our supply is as an economical, well-seasoning packing and core timber: as sawn packing stock and as low-cost core veneer, on the same reasoning that makes it popular across the trade — it is cheap, dries flat, and treats well.

So when subabul is the right, budget-driven answer for a job, it typically shows up in our sawn timber and in the plywood packing cases and crates and plywood pallets we build, or as core in commercial plywood and blockboard and flush doors. For most Kerala-sourced orders we will steer you to rubberwood or the appropriate face veneer, and reserve subabul for cases where its low cost and easy seasoning genuinely fit the brief. Whichever timber suits, we will always specify treatment where the packaging will see moisture or export transit. Browse the full range on our products page, or see the other species we work with on woods we use.