1 Species
During the growing season (spring through summer), apply a balanced organic fertilizer once per month when temperatures are above 60°F (15°C). For optimal growth, use a slow-release fertilizer like pelleted chicken manure, or apply a liquid fertilizer diluted to half strength every two weeks. Avoid heavy nitrogen-based fertilizers in late summer and fall as they can inhibit autumn color development. Reduce fertilizing frequency during fall/winter months when growth naturally slows down. For container-grown bonsai, choose specialized fertilizers designed for potted plants that account for limited root space.
The macro-nutrients from a balanced fertilizer are essential since Rowan bonsai require more nutrients than larger trees due to their small size and frequent pruning. Exercise caution not to overfeed, as too much fertilizer can damage the roots. Consider using dilute foliar sprays during hot, dry periods to provide additional nutrients, following manufacturer instructions carefully.
Position your Rowan bonsai in a location with bright, indirect sunlight, ideally receiving at least 6-8 hours of sun daily. While they can tolerate both warm and cold temperatures, protect the tree from extreme conditions. During hot summers, provide afternoon shade and increase humidity through misting to prevent leaf scorch. In winter, protect the tree from freezing temperatures, particularly if kept outdoors, by moving it to a cool, well-lit location or providing proper insulation.
For indoor display, place near an east or west-facing window to ensure adequate light while avoiding direct afternoon sun. Rotate the tree periodically to promote even growth. When displaying outdoors, choose a sheltered spot protected from strong winds and excessive heat. Remember that Rowans require a period of winter dormancy, so ensure they experience seasonal temperature changes while protecting them from extreme cold.
Pruning should be performed regularly throughout the growing season, with major structural work done during late winter or early spring. Start by removing any dead, damaged, or diseased branches. For structural pruning, focus on maintaining 5-7 main branches depending on your desired style. Trim new shoots just above two buds to encourage proper branching and create denser foliage pads.
Use sharp, clean scissors for precise cuts, and avoid heavy pruning tools that might damage delicate branches. The Rowan responds well to defoliation techniques, which can help reduce leaf size and promote ramification, but this should only be done on healthy trees during appropriate seasons. When pruning for shape, maintain the tree's natural form while gradually working toward your desired bonsai style. Regular pinching of new growth helps create finer branching and maintains the tree's compact form.
Repot your Rowan bonsai every 2-3 years in early spring before new growth begins. Use a well-draining bonsai soil mix rich in organic matter, combined with components like pumice or perlite to ensure proper drainage. The container should be no more than 8 inches deep to reduce stress on the young roots. Choose either plastic or glazed clay pots depending on your climate, avoiding unglazed terra-cotta which can dry out too quickly.
During repotting, carefully prune dead or overgrown roots using clean, sharp scissors designed for bonsai work. Trim the roots gradually to avoid shocking the tree, and ensure the root ball remains intact. After repotting, water thoroughly and keep the tree in a sheltered location until new growth appears, indicating successful root establishment.
Maintain consistent moisture levels without overwatering, as Rowan bonsai are susceptible to root rot. Water when the top inch of soil feels dry to the touch, ensuring the soil remains damp but never soggy. During active growth periods, especially the first two years, water regularly but allow slight drying between waterings. Use either rainwater or distilled water when possible, as tap water may contain chemicals harmful to the roots.
Increase watering frequency during hot, dry periods and reduce it during winter dormancy. Using a moisture meter can help maintain optimal water levels. Regular misting helps increase humidity and keeps the foliage clean, particularly when the tree is kept indoors. Apply mulch around the root system to help regulate moisture content and prevent rapid evaporation.