Black Olive Bonsai – A Timeless Beauty

Learn how to grow and care for a black olive bonsai tree. This ancient Mediterranean species is surprisingly easy for beginners. Get tips on light, watering, pruning, styling, wiring, repotting and propagation to create beautiful bonsai.

The black olive tree has been cultivated for thousands of years in the Mediterranean region. Its gnarled, twisting trunk and silvery-green foliage have made it a popular choice for bonsai enthusiasts around the world. If you’re interested in growing a black olive bonsai, read on to learn about its history, care requirements, and artistic styles.

A Rich History

Olive trees are amongst the oldest cultivated trees, with evidence of olive oil production dating back to 4000 BC in ancient Palestine. The olive held immense cultural significance in ancient Greece and Rome. In fact, the olive wreath was the greatest athletic prize awarded at the ancient Olympic Games.

Olives spread throughout the Mediterranean as the Greek and Roman empires expanded. Arab conquests brought olives to North Africa, the Middle East, and parts of Europe in the 7th century AD. Spanish missionaries carried olive cuttings to the New World in the 16th century.

The earliest documented olive bonsai dates to 1625 in Japan after the tree was likely introduced from China. However, it’s possible that the olive’s ethereal beauty inspired bonsai artists long before this in the Mediterranean region where the tree originated.

Caring for Your Black Olive Bonsai

Despite its ancient heritage, the black olive makes a superb bonsai for beginners. It is surprisingly resilient and forgiving compared to other bonsai species. With just a little knowledge, your olive bonsai will thrive for decades.

Light and Temperature

Olive bonsai need plenty of direct sunlight – at least 6 hours per day. In the hottest summer months, provide afternoon shade or the leaves may scorch. Avoid exposing the trunk to direct sun which can lead to cracking or splitting of the bark.

Hardy to about 20°F, olive bonsai can be grown outdoors year-round in USDA hardiness zones 9-11. In cooler regions, they must be overwintered indoors or in a heated greenhouse. A sunny window or grow lights are essential during this period.

Watering

Allow the soil to dry slightly between waterings, then saturate until water runs out the drainage holes. Olive bonsai are relatively drought tolerant once established but perform best with consistent soil moisture. Discolored leaves or shriveled branches are signs of underwatering.

In winter, allow the soil to dry out more between waterings to avoid root rot when growth is minimal. Increase humidity around the tree by setting the pot on a humid humidity tray or using a cool mist humidifier nearby.

Soil and Fertilizer

A fast-draining bonsai soil mix is essential to prevent waterlogged roots. A blend of akadama, lava rock, pumice and horticultural charcoal is ideal. Olive bonsai also benefit from the addition of a worm compost to provide nutrient-rich humus.

Feed every 2-3 weeks during the growing season with a balanced liquid fertilizer diluted to half strength. An organic bonsai fertilizer cake can provide gentle nutrients throughout the year.

Pruning and Styling

The gnarled, twisting trunks and sparse foliage of olive bonsai are achieved through careful pruning and styling over many years.

Prune to shape in early spring before bud break. Use bonsai pruning shears to selectively remove branches, leaving the silhouette you desire. Seal any cuts over 1/4 inch with cut paste to prevent disease.

In summer, defoliate the tree by plucking off each leaf individually, leaving just a few at the tips of each branch. This process, leaf pruning, causes the olive to sprout an abundance of new, compact foliage.

The olive’s knotted, curved trunk can be wired for shaping at any time. Go slowly and rewire every few months to set the desired form. Remove wires before they cut into the wood.

With creative pruning, you can achieve formal upright, informal upright, semi-cascade, and even windswept bonsai styles from this versatile species.

Repotting

Repot olive bonsai every 2-3 years in spring before bud break. They can remain in the same pot for many years if the root mass is pruned and replenished with fresh soil at each repotting.

Use a bonsai pot that is slightly larger than the root mass and has excellent drainage holes. Glaze porosity is important to allow air to reach the roots.

Propagation

You can propagate olive bonsai from hardwood cuttings or air layers. For cuttings, take 6-8 inch stems in winter while the tree is dormant. Allow the cuttings to callus over for 2-3 weeks, then insert into a mix of potting soil and perlite or vermiculite. Bottom warmth of 70-75°F from a seedling heat mat will encourage rooting.

For air layers, girdle a branch in spring by removing a ring of bark and wrapping with sphagnum moss. Roots will emerge into the moss in 3-12 months. Then cut off the air layer and plant into a bonsai pot. This clones the exact form of the parent tree.

With their effortless beauty and easy care, black olive bonsai make wonderful long-term houseplants. By understanding their needs, you can maintain these living sculptures for a lifetime.