CAROB BONSAI

The Carob Tree Bonsai: The Living Sculpture of the Mediterranean

The Carob tree(Ceratonia siliqua) is not a tree for those in a hurry; it is a companion for life. A symbol of the landscape of southern Italy and coastal areas, it is an extraordinary evergreen essence for bonsai because of its dark green, glossy, leathery compound leaves and its trunk that becomes tormented and rich in natural dry wood as it ages. It is a hardy plant, accustomed to surviving in extreme conditions among sunny rocks, making it hardy but demanding on one factor: drainage.

Origin & species

Native to the Mediterranean basin and the Middle East, it belongs to the Fabaceae (leguminous) family. It is a dioecious species, that is, there are male trees and female trees: only the latter produce the fruits (locust beans) if pollinated. Its wood is very hard, almost like stone, which makes it perfect for creating Jin and Shari (dry wood) that will last over time without rotting easily.

Exposure and Microclimate

The Carob tree is a child of the sun.
It needs to be in full sun all year round. Only then does it reduce leaf size and maintain short internodes.
It loves heat and ventilation. Unlike other species, it does not fear salty air, so it is perfect if you live near the sea. In northern Italy, in summer, give it the warmest and sunniest position you have.

Watering

Although it is drought-tolerant in the wild, things change in pots. Water when the potting soil is dry, but do not overdo it.
Carob tree's number one enemy is root rot. If the soil stays soaked too long, the roots die quickly. It drinks a lot in summer, but always make sure the water drains away quickly from the drainage holes.

Water quality

It is a "foul-mouthed" plant. Being typical of calcareous soils, it tolerates hard tap water much better than maples or azaleas. Of course, rested or rainwater is always preferable to avoid excessive salt buildup in the long run.

Substrate

No messing around here: you need perfect drainage. The Carob tree suffers tremendously from "wet feet."

  • Recommended mix: 50% Pumice (essential for air), 30% Akadama and 20% Lapillus or fine gravel.
  • If you live in torrid areas, you can add a pinch of universal potting soil or humus (maximum 10-15%) so you don't have to water every 3 hours, but the base should be inert and grainy.

Repotting

This is the most delicate time. Carob tree roots are sensitive to trauma.
When: Late spring (May), when temperatures are stably high. Never repot in winter.
How: Never denude the roots completely (always leave some of the old loaf of soil near the trunk) and do not prune the root system drastically. Use pots capacious: Carob trees like to have room for deep roots.

Fertilization

Fertilize with slow-release organic products from March to June and from September to November. As a legume, it has the ability to fix atmospheric nitrogen thanks to symbiotic bacteria in the roots, so do not overdo it with overly nitrogenous fertilizers that would only make the leaves stretch out of proportion.

Flowering and fruiting

In pots it is rare and requires mature plants (often over 20 years old) and the presence of specimens of the opposite sex nearby. Flowers appear in late summer/autumn, directly on old wood (cauliflory). Carob trees take a full year to mature. Enjoy the beauty of the foliage and bark more than the fruit.

Structure pruning

The wood is extremely hard. Large cuts should be made in late winter. Use well-sharpened and disinfected tools. If you create dry wood (Jin), know that on the Carob tree it is very aesthetic and natural, reminiscent of centuries-old olive trees.

Maintenance pruning

Carob has very strong apical dominance: it tends to shoot long branches upward.
Staple (topping) new shoots throughout the growing season when they have produced 4-5 leaves, shortening them to 2. This is to thicken the stakes, otherwise you will have long, bare branches with leaves only at the tips.

Tying & bending

Branches become stiff very soon and break if forced.
Tying should be done on young, still green or semi-woody twigs. For large branches, forget wire: use ties (wires anchored to the pot or other branches) to gradually lower them. If you use wire, check it often because vigorous growth can cause it to become incarcerated.

Diseases and pests

It is a rock, but watch out for:

  • Mealybug: It sticks under leathery leaves or on branches.
  • Powdery mildew (White mildew): Rare, but possible in moist, poorly ventilated areas.
  • Root fungi: If you overwater. Prevent with copper or trichoderma products in the soil.

Winter & protections

Not an alpine tree. It withstands brief light frosts (-1°/-2°C) if the soil is dry, but if you live in the North or in inland areas, from November to March it should be sheltered in a cold greenhouse (ideal temperature between 2°C and 10°C). In the South it can stay outside all year round, perhaps sheltered from cold north winds.

Annual calendar

  • January-February: Protection from the cold, processing dry wood.
  • March-April: Vegetative resumption, start fertilizing.
  • May: Repotting (optimal time), selection pruning.
  • June-August: Continuous pruning, careful watering, full sun.
  • September-October: Fall fertilization (phosphorus and potassium).
  • November-December: Winter sheltering (in the north), cleaning.

Useful products for this bonsai

Carob Tree Frequently Asked Questions

Can I start a bonsai tree from a carob seed?
Yes, they germinate easily, but growth is very slow. It will take years before you have a workable trunk. It is a good exercise in patience, but if you want aesthetic results in human time, better to start from nursery or pre-bonsai material.

Why are the leaves closed or folded down?
The Carob tree sometimes "closes" its leaves to reduce transpiration if it is too thirsty or too hot, or at night (noctynastic movement). However, if they remain closed and sad even during the day with moist soil, there is a root problem.

Can Carob trees be defoliated?
Yes, partial defoliation can be done in June on very strong plants to reduce leaf size, but it is a stressful practice. Constant stapling and lots of sun is often enough to get small leaves without risk.

How do I treat dry wood (Jin)?
Carob wood is wonderful for this. Once you have debarked the dead branch, let it dry and wipe it with Jin liquid (calcium polysulfide) to bleach it and protect it from fungus. It should be reapplied once or twice a year.