Jooni
Amur Maple
1 Species
Species
Fertilizing
Begin fertilizing in spring with the first leaf emergence and continue until early September. For optimal results, use organic fertilizers that release nutrients slowly and contain necessary trace elements. Apply liquid fertilizer every 2 weeks following package instructions, or use organic solid fertilizer like Biogold every 4-6 weeks. Avoid mineral fertilizers as they risk over-fertilization and can cause excessive growth.
Placement
Position the tree outdoors in a sunny location, with some protection from intense midday sun during peak summer months to prevent the bonsai pot from overheating. This winter-hardy species can withstand temperatures down to -20°C (-4°F) and should be kept outside year-round. During winter, protect it in an unheated tent or cold frame that prevents drying out. Never overwinter indoors.
Pruning
Amur maple responds extremely well to pruning and quickly forms new buds after cutting. You can prune several times annually until early August to refine branching. For development, allow shoots to grow freely if you want to thicken branches. For maintenance and refinement, you can cut back or pinch 2-3 times per year. The tree tolerates leaf pruning well and can be kept compact through regular maintenance. Let new shoots grow if you want to thicken branches, otherwise maintain the desired silhouette through regular trimming.
Wire very thin shoots immediately after sprouting using 1mm copper or 1.5mm aluminum wire. The branches typically lignify within 4-6 weeks, allowing wire removal while maintaining the new shape. Late wiring increases breakage risk. Monitor wire regularly as the smooth bark marks easily, though these marks eventually grow out.
Repotting
Repot every 2-3 years in early March when buds begin swelling, using well-draining bonsai soil like Akadama mixed with materials like Kiryu or expanded slate for enhanced drainage. The vigorous root system tolerates aggressive pruning - remove 30-50% of roots during repotting. Fall repotting is possible but spring is optimal. After root pruning, the tree quickly develops new strong roots, making it excellent for developing nebari. Mycorrhiza additions aren't necessary as the species grows well without it.
Watering
Water thoroughly when the soil begins to dry due to the tree's vigorous growth and high water consumption, especially in sunny locations during summer. While relatively drought-tolerant compared to other maples, maintain regular water checks even in winter. Use well-draining soil like Akadama to prevent waterlogging issues. The species is somewhat forgiving of temporary drought conditions and less prone to leaf tip burn than other maples.