Dalbergia cultrata Seeds | Rosewood

Dark, dense heartwood and pale sapwood at the end of a freshly cut rosewood log — Rosewood (*Dalbergia cultrata*): Fabaceae, dry forests of mainland south-east Asia.

LATIN NAME: Dalbergia cultrata

COMMON NAME: Rosewood

Plant Profile

Dalbergia cultrata is one of the several south-east Asian rosewoods, a tall deciduous tree of the dry monsoon forest with pinnate leaves, small white pea flowers and a dark, dense heartwood that rings when struck. It grows twenty to thirty metres in good ground, with a straight bole and a spreading crown, and it is slow: a tree worth cutting may be a century old. The wood is the reason it is known, and the reason its wild populations are under pressure. In the dry season the tree is briefly bare, and the new flush comes with the first rain. The leaflets are alternate, seven to thirteen to a leaf, and they are shed in the dry season, leaving the crown open and grey.

Science & Biotechnology

The genus Dalbergia is chemically defined by neoflavonoids and by the aromatic oils of its heartwood, and D. cultrata has been characterised in timber-identification work as part of the rosewood complex. Since 2017 the whole genus has been listed on CITES Appendix II, with a small number of exceptions, which means international trade requires permits and provenance documentation. DNA barcoding and wood anatomy are now used to check declarations, because the sawn wood of the various rosewoods is hard to tell apart by eye. The species nodulates and fixes nitrogen, which makes it useful in the poor soils of its native dry forest. Growth-ring studies show that the species puts on most of its diameter in the few weeks of the wet season, which makes its wood unusually dense.

Uses & Benefits

The heartwood is dark, hard, close-grained and takes a glassy polish, and it has been used for furniture, cabinets, musical instruments, knife handles and carving, which is the whole commercial story of the species. Its flowers are a minor honey source and the foliage is fodder in dry seasons. In the garden it is a slow, handsome shade tree for a large warm site, grown for its crown and its scent rather than for timber, and planted trees are the only responsible source of the wood. Old stumps coppice, which is one argument for managing it rather than mining it. The tree also yields a gum and a fibre, and in parts of Laos the bark is used in tanning, though none of these matches the wood in value.

Growing from Seed

Treat the seed as hard-coated: nick the edge with a file or pour boiling water over it and leave it to soak for a day. Sow into a free-draining mix at twenty-five to thirty degrees and expect germination, unevenly, over three to six weeks. The seedling is fast for a rosewood but the tree is slow to make heartwood. Give full sun, deep soil and a dry season, and do not overwater, because the species is built for monsoon contrasts rather than constant damp. In a pot it needs a deep root run, so use a tall container rather than a wide one, and expect to plant it out within two years.

Our Take

A rosewood is a hundred-year investment, and the only honest way to own one is to plant it. Buy seed from managed sources and leave the wild stands alone.

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