False Acacia

Fertilizing

Feed your False Acacia every two weeks during the growing season using a balanced fertilizer. Since this species can fix nitrogen from the air naturally, nitrogen-rich fertilizers aren't necessary during early growth. For mature trees, reduce feeding frequency in winter.

A unique advantage of Robinia pseudoacacia is its ability to enrich the soil through nitrogen fixation. During spring growth periods, you can supplement with a phosphorus-rich fertilizer to encourage flower development and strengthen the root system.

Placement

Position your False Acacia bonsai outdoors in full sun, with at least 6 hours of direct sunlight daily. While it can tolerate partial shade, maximum sun exposure promotes optimal growth and flowering. Protect from strong winds that can damage its brittle branches. This hardy species only needs frost protection when temperatures drop below -10°C.

Pruning

Trim new growth regularly during the growing season to maintain shape. Perform hard pruning after leaf fall in autumn. Remove basal suckers promptly unless desired for the design. When wiring, use the correct wire thickness - matching the branch diameter to avoid bark damage. False Acacia works well for informal upright and multiple-trunk styles. Be careful not to remove all growing tips, as this can weaken the tree.

Maintenance pruning helps develop ramification and maintain the compact bonsai form. Cut back long shoots that extend beyond the desired silhouette throughout summer. During structural pruning, ensure clean cuts and proper healing to maintain the tree's health.

Repotting

Repot young False Acacia bonsai every 2-3 years in spring, just before new growth appears. Use a well-draining soil mix with neutral to slightly acidic pH (5-6). For mature specimens, extend the repotting interval to 4-5 years. When repotting, don't prune the roots too aggressively - retain the finer feeder roots while removing thick circling roots.

A basic mix of akadama, pumice, and lava rock in equal parts works well. After repotting, place the tree in a shaded area for several weeks before gradually reintroducing to full sun.

Watering

Water regularly but allow the soil to dry slightly between waterings. False Acacia prefers drier conditions and is susceptible to root rot from overwatering. Check soil moisture by feeling the surface - water thoroughly when the top inch feels dry. During hot summer months, you may need to water daily.

References

Green Zen Bonsai - False Acacia Care Guide Miyagi Bonsai - False Acacia, Black Locust Bonsai Care Guide Bonsai Tree Gardener - Robinia pseudoacacia Care Guide