Culture
Winter hardy to USDA Zone 7, but may survive winters in Zone 6 if sited in a protected location and mulched. This shrub is best grown in humus-rich, acidic, moderately fertile, consistently moist, well-drained soils in full sun to part shade. Tolerates full shade. Best with part afternoon shade in hot summer climates. Clip off growing tips as needed in mid to late spring to maintain compact size and to encourage bushiness. Propagate from stem cuttings. Where not winter hardy, shrubs may be grown in containers which must be overwintered indoors in bright cool locations in temperatures ranging from 45 to 55 degrees F.
Noteworthy Characteristics
Osmanthus armatus, commonly called holly olive, is a dense, upright-rounded, bushy, broadleaf evergreen shrub that typically grows to 12-17' tall with a spread to 8-10’, but occasionally rises as a small tree to as much as 30’ tall. It is native to thickets and rocky areas on lower alpine slopes in western China (Hubei and Sichuan).
Thick, rigid, spiny, holly-like, glossy deep green, oblong-lanceolate to elliptic leaves (to 6-8” long) are evergreen. Sweetly aromatic, tubular, tiny, creamy white flowers with spreading lobes (to 1/4” across) bloom in fall in small axillary clusters. Plants are dioecious or androdioecious, with fruits appearing only on plants with female flowers. Fruits (to 3/4”) are one-seeded drupes which typically ripen in April (about 6 months after flowering), but are often not produced in cultivation.
Holly olive is similar in appearance to many of the hollies, but its leaves are opposite whereas the leaves of hollies are alternate.
Genus name comes from the Greek words osme meaning fragrant and anthos meaning flower.
Specific epithet comes from the Latin word armatus meaning armed or thorny in reference to the leaves being armed with spines.
Problems
No serious insect or disease problems. Watch for scale and aphids.
Uses
Where winter hardy, this holly olive forms an excellent screen or hedge. Shrub borders. Woodland gardens. Accent. Where not winter hardy, it may be grown in a container that must be brought indoors in fall before first frost for overwintering in a cool location.