Citrus Bonsai Trees: Scent of Zagara and Golden Fruits

The world of Citrus Bonsai trees (genus Citrus) is vast and fascinating. These plants are loved for their glossy evergreen leaves, intoxicating white blooms (Zagara) and, of course, the colorful fruits that often remain on the plant for months, bringing cheer in winter. Although there are many varieties, the cultivation requirements are very similar. In this fact sheet we group the four "stars" of citrus bonsai: the Chinotto, Kinzu, Limequat and Calamondino.

The 4 Main Species in Bonsai

• Citrus Myrtifolia (Chinotto): Classic Italian (Ligurian style). Has very small, dark, tile-arranged leaves, very slow and compact growth. Clustered orange fruits.
• Citrus Kinzu (Fortunella hindsii): The "Hong Kong Kumquat." It is the smallest ever: produces small fruits the size of peas (or slightly more), edible and very decorative. It often has thorns.
• Citrus Microcarpa (Calamondin or Calamondin): A hybrid of mandarin and kumquat. It is most generous: blooms and fruits almost in a continuous cycle. Medium leaves, fruit similar to small tangerines.
• Citrus Limequat: Hybrid between lime and kumquat. Has oval fruits that turn from green to lemon yellow. Very elegant with a fresh scent.

Exposure and Microclimate

All citrus fruits love full sun.
Direct light is the "fuel" needed for flowering and ripening fruits. Without sun, the plant will only make large, green leaves and the branches will spin.
They love breezy air, but detest icy winter currents. In summer, if grown in pots very small (especially the Kinzu), be careful that the pot does not get hot in the sun, cooking the roots.

Watering

Citrus trees drink a lot, but they are very susceptible to root rot.
Water thoroughly when the potting soil is slightly dry on the surface. Water consumption is high in summer.
Caution: Never leave standing water in the saucer. If the leaves yellow and fall off massively, it is often the fault of too much water suffocating the roots.

Water quality

This is the weak point. Citrus trees are afraid of lime scale (ferric chlorosis).
If you use hard tap water, over time the leaves will turn yellow with green veins. Ideally, use rainwater or decanted water, and give chelated iron regularly.

Substrate

The soil should be draining but rich in organic matter.

• Recommended mix: 40 percent Akadama (or fine Pumice), 40 percent high-quality Universal Potting Soil, and 20 percent Lapillus.
• The organic component is higher than for pines or junipers because citrus trees are "voracious" plants.

Repotting

It is done in late spring (May-June), when night temperatures are stable above 15°C. Never repot a citrus tree in winter!
Repot every 2-3 years. Be careful of fragile roots. Always use new, fresh potting soil.

Fertilization

Citrus trees are plants that "eat" a lot.
Fertilize from spring to fall.
It is advisable to use citrus-specific fertilizers (they often contain ground Lupins, which slightly acidify the soil) or organic Japanese fertilizers enriched with Chelated Iron periodically to prevent yellowing.

Flowering and fruiting

Flowers are white and highly fragrant. Fruits follow the flowering.
Golden Rule: Bringing the fruits to maturity costs a lot of energy.
On Chinotto and Kinzu (small fruits) you can leave more. On the Calamondino and Limequat (medium fruits), you must thin out: leave only 2-3 fruits per branch, otherwise the branch may dry out or the next year the plant will not flower (alternate).

Structure pruning

Big cuts are done in late winter, before vegetative recovery.
Always use mastic: citrus wood is hard but tends to dry out if exposed. Remove "suckers" (vigorous vertical branches starting from the base or center) because they steal energy from the fruiting canopy.

Maintenance pruning

Throughout the year, shorten branches that grow too long to maintain shape.
Be careful: many citrus trees flower on the year's branches or at the top of new shoots. If you continually ball-prune, you will never see flowers.

Tying & bending

Citrus branches are stiff and often thorny (especially the Kinzu).
Tying is possible on young (green) branches, but directional pruning or the use of pulls is often preferred. Be careful of thorns as you work the plant.

Diseases and pests

Citrus trees attract many unwanted guests:

• Serpentine Mineratrix: A small larva that digs silvery "tunnels" inside leaves, crumpling them. It affects summer shoots.
• Mealybug: (Scud-like or cottony). Produces sticky honeydew that leads to Fumaggine (black patina).
• Red spider mite: In summer.
• Ferric Chlorosis: Yellow leaves due to lack of iron/calcareous water.

Winter & protections

Depends on area.
South and Islands: They live outside year-round.
North and Central: They do not tolerate prolonged frost. They should be sheltered in a cold greenhouse or a bright unheated room (lemon house) where the temperature is between 4°C and 10°C. If you bring them indoors in dry heat, they will lose all their leaves.

Annual calendar

• January-February: Rest in the cold greenhouse, cochineal control.
• March-April: Iron administration, revival.
• May-June: Repotting (ideal time), flowering, fertilization.
• July-August: Abundant water, mealybug control.
• September-October: Fruit ripening, fall fertilization.
• November-December: Protection from cold weather.

Useful products for this bonsai

• Iron Chelate (Essential for green leaves)
• Akadama (For drainage and fine roots)
• Oblique clippers (For clean cuts)
• Coppered aluminum wire (For setting)
• Healing putty (Wound protection)
• White oil (Against mealybug)

Frequently Asked Questions about Citrus

Are the fruits edible?
Yes, absolutely. The Chinotto is bitter (great candied), the Limequat is tart like lime, the Calamondino is sour and aromatic, and the Kinzu is tiny and has little flesh but is edible (often eaten with the sweet peel). Avoid eating them if you have just treated the plant.

Why do the leaves curl up?
If you see silvery "stripes" on the curled up leaf, it is Serpentine Mineraria. Cut away the affected leaves and treat with specific products or neem oil.

Why does it lose its leaves in winter?
Often it is because of the sudden change in temperature or light. If you move it from outside to inside the house (warm and dry), it will suffer a shock. Look for a cool, bright place (stairs, unheated porch).