Jooni

Elm

3 Species

Species

Ulmus parvifolia Ulmus americana Ulmus minor

Fertilizing

During the growing season (spring through fall), feed every two weeks with a balanced fertilizer (NPK 20-20-20). In winter, reduce to monthly feeding using a lower nitrogen formula (10-10-10) to encourage root growth. Always water thoroughly before applying fertilizer. Both organic and synthetic options work well - organic fertilizers release nutrients slowly and improve soil health, while synthetic ones provide immediate nutrient availability.

Placement

Place the tree in a spot with bright, indirect light. Morning sunlight is ideal due to its low intensity. During summer, the tree can live outdoors but must come inside when temperatures drop below 60°F (15.5°C). Maintain temperatures between 60-70°F (15.5-21°C) and avoid drafty areas. Keep away from direct afternoon sun through windows as it can burn the leaves.

Pruning

Maintenance pruning can be done year-round by allowing new shoots to develop eight leaf pairs before trimming back to two or three pairs. Wiring can be done anytime on mature branches, but only wire new shoots once they become slightly woody. The Chinese Elm adapts well to most styling techniques but is particularly suited to the classical umbrella shape. For structural pruning, focus on removing dead branches and maintaining the desired silhouette during the dormant season.

Repotting

Repot every two years in early spring using well-draining bonsai soil. Chinese Elms can be sensitive to aggressive root pruning, so trim roots conservatively. After repotting, water thoroughly and keep the tree in a shaded location for several weeks to help new roots establish. A quality soil mix should contain akadama, pumice, and lava rock for optimal drainage and aeration. Consider using a mixture of 2 parts loam, 1 part peat moss, and 1 part sand as an alternative.

Watering

Monitor soil moisture daily by inserting your finger half an inch into the soil - water when it feels slightly dry but never let it dry out completely. Water requirements vary seasonally - less in winter, potentially daily in summer depending on climate. Mist the foliage a couple times weekly for humidity but don't consider this a substitute for proper watering. Place the pot on a humidity tray with pebbles to prevent root rot while maintaining moisture levels.

References