The Zelkova bonsai, also called Japanese Elm, is a deciduous tree that originates in Japan, Korea, and Taiwan. It’s a good bonsai tree for beginners because it is easy to care for.
The Zelkova bonsai naturally grows into a broom shape, so is particularly suited to the style. The leaves are green in summer and turn yellow, orange, red, and purple in Autumn.
This tree prefers full sun during growing season, unless the sun is too intense for all-day exposure. Don’t overwater this bonsai species because it can cause root rot.
Position & light: The Zelkova bonsai are grown outdoors and require full morning sun and shade during the hottest part of the day to thrive. The Zelkova must be protected from the hot sun to prevent leaf burn. This tree also needs protection from frost. Put the Japanese elm in a greenhouse, garage, or shed to winter.
Watering: During the hot months of Summer the Japanese elm may require two waterings a day to keep the soil moist. Never let the root ball dry out, but don’t overwater. Drying can kill branches and overwatering can cause root rot. Use water that is not calcareous.
Fertilizing: Use a fertilizer balanced twice a month in early Spring and a low nitrogen fertilizer from Summer to late Autumn.
Pruning: Trim new shoots to two leaves when the Japanese elm has produced four-six leaves. When the leaves fall off, carefully trim back the branches that have grown too long. Leave extensive structural pruning to the Spring. You can remove the leaves of the young Japanese elm in June to improve its structure. Removing the larger leaves on an older, healthy tree will let more light reach the smaller inner leaves, giving the same result.
Wiring: The Japanese elmis best shaped through pruning, though this tree can be wired any time of the year. The best time to wire is when the leaves don’t cover the structure during Autumn, Winter, and early Spring. Take great care in wiring so as not to break branches or scar the tree wiring too tight.
Repotting: Repot the Japanese Elm every year as a young tree and every two-three years as a mature tree. Repot the tree when the roots become pot-bound. Plant the Japanese elm in dry soil that is rich and drains well. Pumice or fuji grit can be added for extra drainage. Don’t compress the soil. Instead shake the pot the flatten the soil. Water the soil immediately after repotting the bonsai.