Firethorn

Fertilizing

During the growing season (March-October), apply fertilizer weekly using Chrysal Liquid Bonsai Feed or a similar balanced liquid fertilizer. Alternatively, use a slow-release organic fertilizer like Naruko every 1-2 months. Ensure sufficient phosphorous and potassium content to promote flowering and fruit development. During winter months, cease fertilization completely.

Placement

Place the Firethorn in a sunny or semi-shaded outdoor location, protected from intense afternoon sun and strong winds. During winter, the tree requires a dormant period with temperatures between 2-12°C. Protect from frost by moving to a cold frame or unheated greenhouse when temperatures drop below freezing. Though frost-hardy, container-grown specimens need extra protection from severe cold.

Pruning

Perform structural pruning in spring or late summer, thinning out dense areas to improve light penetration and air circulation. Throughout the growing season, trim new shoots back to two leaves once they've elongated. The Firethorn tolerates aggressive pruning and buds readily from old wood. When wiring, use caution around thorns and consider removing them first. Older branches are brittle, but young shoots can be wired after summer. For complex bending, guy wires may be preferable to traditional wiring techniques.

Repotting

Repot young trees every two years and mature specimens every 3-5 years in early spring. Use a well-draining soil mix with neutral to slightly alkaline pH (5-7). When repotting, avoid removing more than 25% of the root mass. The tree adapts well to various soil types but requires good drainage. Begin by removing the tree from its pot, rake away outer soil, prune roots as needed, then replant in fresh soil, working it carefully around the roots to eliminate air pockets.

Watering

Monitor soil moisture levels carefully - water thoroughly when the top inch of soil feels dry, but avoid constant wetness. During flowering and fruiting periods in summer, increase watering frequency while remaining vigilant against overwatering. In winter, reduce watering frequency but never allow the root ball to completely dry out. Consider using a moisture meter initially to learn the tree's water needs. For container-grown specimens indoors during winter, place the pot on a humidity tray filled with gravel and water.

References

Bonsai Empire - Pyracantha Care Guide Miyagi Bonsai - Firethorn Care Guide Green Bonsai - Firethorn Care Instructions