Eucalyptus Wood is harvested from a family of fast-growing tropical shrubs and trees. ... Eucalyptus heartwood is red to reddish-brown, and darkens as it seasons. Its sapwood is pale cream. The grain of this tree is slightly interlocked, with sometimes ripply or fiddleback patterns. It has a medium to coarse texture. It is moderately resistant to termites, but susceptible to marine borers and pinhole borers. Cut eucalyptus will stay strong and dense for a long time; logs have been known to lie in wet forests for 10 to 20 years without heartwood decay.