4mm, Anodized aluminium wire

Use suitable wire to shape a bonsai tree, which will retain its form even when the wire is removed weeks or months later. Wire deciduous trees in late spring through autumn, and evergreens like pines and junipers in winter. Annealed copper wire is best for evergreens, while anodized aluminium wire is preferred for deciduous trees. Other uses include guy wiring and securing freshly repotted trees.