SUMMARYGrevillea cv. 'Crimson Yul-lo' has large bright red terminal inflorescences on leafy stems and has recognised commercial potential as a cut flower crop. A major limitation is its relatively short vase-life, often terminated by early wilting of the inflorescence despite apparently turgid leaves. An investigation of the water relations of cut Grevillea 'Crimson Yul-lo' stems revealed that the water potential of inflorescences on intact stems in vases was significantly higher (i.e., less negative) than that of leaves from day-0 to day-3 of vase-life. Thereafter, the water potential of inflorescences declined more rapidly than that of leaves, accompanied by visible wilting of the tepals and styles of individual florets. Removal of leaves from the stems reduced both water uptake and water loss, and delayed the onset of a negative water balance in the inflorescence. Bagging of entire stems, leaves only, or inflorescences only, with microperforated plastic film to reduce transpiration, reducing leaf number to reduce leaf area, or supplying abscisic acid to reduce leaf stomatal aperture, all aided relative fresh weight retention by stems and extended vase-life. Four or six leaves on a stem caused greater loss in inflorescence water content than zero or two leaves. Considered collectively, these findings show competition for water between the inflorescence and the leaves in cut Grevillea 'Crimson Yul-lo' stems contributes to the onset of inflorescence wilting and their short vaselife.3 revillea is a large genus within the family Proteaceae and it contains over 300 species (Joyce and Beal, 1999), many of which are grown world-wide (Costin and Costin, 1988;Joyce and Beal, 1999;Joyce, 2004). Many grevilleas, especially hybrids of subtropical and tropical species, are woody shrubs or small trees with attractive large, colourful inflorescences and soft, divided fern-like foliage that make them appealing as landscape plants. Their inflorescences also have commercial potential as cut flowers (Costin and Costin, 1988;Joyce, 2004), but a major limitation to their use as cut flowers is their relatively short vase-life of often less than 1 week (Faragher, 1989;Joyce et al., 1996;Joyce and Beal, 1999;Joyce, 2004). Cut stems of Grevillea 'Crimson Yul-lo' (Grevillea banksii × Grevillea 'Misty Pink') have large bright-red terminal inflorescences consisting of 90−120 florets at various developmental stages arranged along a single floral rachis ( Figure 1A, B), but the inflorescences have a vase-life of only three-four days in water.A number of factors influencing the longevity of cut Grevillea flowers have been studied.The vase-life of Grevillea 'Majestic' inflorescences harvested in Winter was generally longer than that of Summer-harvested inflorescences (Vuthapanich et al., 1993). The vase lives of Grevillea 'Sylvia' and Grevillea 'Honey Gem' were dependent upon the harvest maturity stage, with optimum maturity being characterized by opening of the lowest florets (Joyce and Beal, 1999). Addition of sucrose to vase solutions imp...