Korean Hornbeam Bonsai
Korean hornbeam is one of the most beloved of all species used for bonsai.
It is famous for:
● Delineating vascular lines that carry through the tree’s smooth, creamy white bark
● Rugged cracks in the aged trunk
● Fantastically angular branching
● Dainty leaves
● Fantastic fall colors of red and yellow hues
Hornbeam bonsai is the truest contrast of rugged and delicate, old and new.
Caring for Korean Hornbeam Bonsai
This broadleaf deciduous tree has tremendous breadth in terms of tolerance for watering.
Korean hornbeam bonsai trees like to be on the drier side and should be allowed to almost dry out between waterings.
Korean hornbeam bonsai require a dormant period for optimal health.
To achieve this, the tree should be kept outdoors—except for being brought inside for special occasions. Root protection is necessary for extremes in temperature during the winter months.
Korean hornbeam bonsai love full sun, with the cut-off for full sun being spring into early summer. During mid to late summer, when afternoon sun and temperatures become extreme, the tree requires 30% shade.
The Korean hornbeam bonsai is tolerant of full sun up to 95° Fahrenheit, even in low relative humidity, and will grow well as long as the leaves have hardened off and formed their cuticle to prepare for the heat.
Korean hornbeam bonsai are also very durable to the cold, showing tolerance to 20° Fahrenheit for medium and larger-sized trees.
Korean hornbeam bonsai thrive best with moderate fertilization that is applied consistently throughout the year.
When fertilized heavily, it tends to increase the amount of time and labor needed to care for the tree and will cause abnormally long internode links that are challenging to use if you want to refine.
It's ideal to prune Korean hornbeam bonsai twice a year.
The first pruning is at leaf drop in the fall. This is the best time to reduce the density of tertiaries and prune back secondaries. It's also a wonderful time to prune primary branches to avoid a significant amount of die-back down the trunk.
The second time to prune Korean hornbeam bonsai is post-flush harden pruning in the late spring/early summer. This is the time to adjust the length of new growth and partially defoliate to incite a second flush of ramification.
The tree may also be pruned in the spring, as the buds swell prior to bud growth, but this does tend to throw off the balance of the tree and should only be applied on an as-needed basis.
During the spring, as the buds swell, is the only time to repot Korean hornbeam bonsai. Repot with solid Akadama—up to ¼ inch aeration layer.
The main thing to note about repotting Korean hornbeam bonsai is to observe proper management of the surface of the soil and reduce action that allows water percolation into the shin (the dense root mass growing directly under the trunk). That means every time you repot, you must appropriately manage the surface of the soil so you are able to get water and oxygen into the shin to maintain health.
Always be respectful of the shin when repotting. Inspect it to make sure it's not compacted and that it hasn't somehow developed a poor biology—such as a potential bacterial accumulation in pockets of dead root or compressed soil mass. By taking care to maintain the shin, you'll be able to preserve the health of the apex of the tree as well as the upper branching.
Korean hornbeam bonsai are propagated through semi-hardwood and hardwood cuttings, and they will readily root when laid down in a raft style.
Korean hornbeam bonsai are incredibly durable trees — and are an agreeable species when it comes to pests and disease.
The main issues you may observe are:
● Aphids on new growth
● Spider mites if trees are fed too aggressively or kept in excessively hot, dry locations where the upper canopy may become a tempting meal