| Common Name: |
Dwarf Black Olive, Spiny Black Olive |
| Scientific Name: |
Bucida spinosa |
| Hardiness Zone: |
Zone 10B through 11 |
| Family: |
Combretaceae |
General Information
8 species, south Florida, West Indies, and Central America. Shrub or flat-topped tree, 4-8 m tall; branches spreading; twigs divaricate; spines slender, 3-7 mm long, mostly in 3's at end of twigs. Used as an indoor ornamental in large planters, and also a popular bonsai subject. Native to Cuba, the Bahamas. (See Bucida buceras for more general information).
Basic Care
| Bark Characteristics: |
Old Bucida's may have rugged bark, while newer trees grown in nurseries have smoother bark. The sapwood is thick, pale-yellow or light-brown and not as durable as the heartwood. The heartwood is light yellow-brown or dark-brown, sometimes streaked with orange. |
| Leaf/Foliage Characteristics: |
Leaves fascicled, subsessile, oblanceolate to spatulate, 1-2.5 cm long, 4-6 mm wide, firm, margins entire, obtuse or retuse at apex, narrowed at base. |
| Growth Characteristics |
Branches grow in a tiered fashion with individual twigs grow in a sig-zag pattern. Some trees are spineless, but others often bear shaper 1/4" to 3/4' long spines on the young lower branchlets. |
| Flower/Fruit Characteristics: |
Flowers greenish, in short axillary subcapitate spikes, peduncles short; calyx campanulate, to 3 mm long, subtruncate, villous within; stamens 8 or 9, to 3 mm long. Fruit a drupe, ovoid, 3-4 mm long, calyx early deciduous. |
| Lighting: |
Full sun, protect when tempertures approach 40 degrees F. |
| Watering: |
Keep well watered, reducing watering only slightly for younger trees. |
| Feeding: |
Use a well balanced fertilizer. |
| Pruning/Wiring: |
The top of the tree may be pruned heavily during the summer months. The branches form a natural zig-zag pattern making wiring relatively fun and easy. Be careful with smaller branches as they are brittle. Remove flowers from the tree as they appear, to encourage greater branch growth. |
| Propagation: |
The black olive is difficult to propagate. Growth may be fast or slow. It has been calculated that there are 38,000 seeds per 2.2 lbs. The seeds germinate 12 to 17 days after planting in a nursery but many are damaged by insects. Only 2500 of the seeds in the 2.2 lbs. may actually grow. Many seedlings do not survive transplanting. In rich soil, some may reach 30 ft. in height in 10 years. Terminal softwood cuttings succeed well in a mist-bed. Air-layering is also a practical means of propagation. |
| Potting: |
Roots are sensitive to major work. Reduce rootball over several repottings. Repot during the summer months in a well draining soil. |
| Pests: |
Philaphedra scale causes the black olive to lose all its leaves; the mite Eriophyes buceras prevents normal fruit development, causing long, string beanlike galls. Both galls and leaves are high in tannin that stains sidewalks, vehicles, white roofs and cement decks. Black olive trees are often subject to attack by large flights of the Keys whitefly (Aleurodicus dispersus), which exude honeydew, resulting in Sooty Mold. Bark borers. |
| Diseases: |
Sooty mold. |
| Bibliography: |
THE BLACK OLIVE (BUCIDA BUCERAS L.), A Tropical Timber Tree, Has many faults as an ornamental; Proc. Fla. State Hort. Soc. 106: 1993. ; Julia F. Morton, Morton Collectanea, University of Miami Coral Gables, FL 33124 |
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