How to Care for an Ehretia Microphylla

The Ehretia microphylla, commonly known as the Fukien Tea Tree or Philippine Tea Tree, is a tropical shrub from Southern China popular for indoor bonsai. Its popularity stems from characteristics ideal for the art form, including small, glossy green leaves and a tendency to develop a thick, gnarled trunk. The plant produces delicate white flowers throughout the year. If pollinated, these flowers give way to small, decorative red berries, adding to its appeal as a miniature tree.

Essential Care for Ehretia Microphylla

The Fukien Tea Tree thrives in bright, indirect light. An ideal indoor location is a south-facing windowsill, though an east or west exposure is also suitable. While it needs several hours of daily sunlight, intense, direct sun can scorch its leaves. Insufficient light will hinder its growth and ability to flower, so a grow light can be used if natural light is limited.

This species prefers consistently moist but never waterlogged soil. Before watering, check if the top inch of soil feels dry. Apply water until it flows freely from the pot’s drainage holes. Avoid letting the plant stand in a saucer of water, as this can lead to root rot.

A well-draining bonsai soil mix provides the necessary drainage and nutrients. A suitable medium can be created by combining loam, peat moss, perlite, and sand for good aeration and moisture retention. The soil should be slightly acidic, with a pH between 6.0 and 6.5, and rich in organic matter.

As a tropical native, Ehretia microphylla flourishes in warm, humid conditions. It prefers temperatures between 60 and 72 degrees Fahrenheit and is sensitive to cold drafts and sudden temperature drops. To increase humidity in dry indoor environments, mist the foliage daily with non-calcareous water. You can also place the pot on a tray filled with pebbles and water.

During the spring and summer growing season, feed the plant every two to four weeks with a balanced, water-soluble fertilizer. Dilute the fertilizer to half-strength to prevent root burn, and always water the plant thoroughly before application. In the fall and winter, reduce fertilization to once a month as growth slows.

Pruning and Shaping Techniques

Regular pruning is necessary for both the health and aesthetic shape of an Ehretia microphylla. Maintenance pruning involves pinching off new growth throughout the growing season. This encourages the plant to become denser and more compact, maintaining its desired shape.

Structural pruning is more intensive and defines the plant’s form. This involves cutting branches with at least eight leaves back to just two or three to encourage ramification. This is best performed during active growth in spring and summer. At this time, also remove any dead branches or yellowed leaves to keep the plant healthy.

Always use clean, sharp tools like secateurs or bonsai shears to minimize damage and reduce disease risk. Make cuts just above a node, where new growth will sprout. For bonsai, wiring can guide branch growth, but care must be taken as the branches are brittle.

When and How to Repot

An Ehretia microphylla needs to be repotted every two to three years. Signs that a plant has outgrown its container include roots circling the inside of the pot, poor water drainage, or the plant appearing top-heavy. These indicators suggest the root system has exhausted its available space.

The best time to repot is during early spring or mid-summer when the plant is actively growing. Carefully remove the tree and its soil from the pot. Gently rake away old soil from the outer root mass to expose the roots. Using clean shears, trim the outer one-fourth of the root ball to encourage new growth.

Place the tree back into its original pot or a slightly larger one with fresh, well-draining soil. Ensure a screen covers the drainage holes. Position the tree at its original height and fill the surrounding area with the new soil mix, avoiding air pockets. After repotting, water the plant thoroughly to ensure complete saturation.

Propagating from Cuttings

New Ehretia microphylla plants can be propagated from softwood cuttings. This is best done in spring or early summer during vigorous growth. Select a healthy, soft branch and use a clean tool to take a cutting approximately ten centimeters long. Make the cut just below a node to encourage rooting.

Prepare the cutting by removing the lower leaves and cutting the remaining leaves in half to conserve moisture. Plant the cutting in a pot with a moist, well-draining substrate like a seedling mix. Use a pencil to create a pilot hole in the soil before inserting the cutting to avoid damage.

Maintain a warm and humid environment for the cutting by covering the pot with a clear plastic bag or placing it in a mini-greenhouse. This technique traps humidity, creating ideal conditions for root formation. Keep the soil consistently moist, and the cutting should establish a root system within a few weeks.

Troubleshooting Common Issues

Yellowing leaves or sudden leaf drop are common issues. These symptoms are often related to improper watering, either too much or too little. They can also be a sign of stress from a sudden temperature change, such as placement near a cold draft.

The Fukien Tea Tree is susceptible to pests like spider mites, scale, and mealybugs, especially indoors. Spider mites thrive in dry conditions, so increase humidity by misting the foliage to deter them. For scale or mealybugs, manual removal or treatment with an appropriate insecticidal soap may be necessary.

A lack of flowers on a mature plant is often linked to insufficient light. If your Ehretia microphylla is not blooming, move it to a brighter location with more indirect sunlight. Improper fertilization can also be a factor, so ensure you are feeding the plant regularly during its growing season.