As an evergreen tree, the cork oak is particularly popular in bonsai art. This species also develops comparatively small leaves in an alternate arrangement. The furrowed bark on the trunk and older branches completes the overall picture.
How do you care for a cork oak bonsai?
A cork oak bonsai needs a bright to full sun location, regular watering and fertilization from spring to late summer and repotting every two years. In winter, a frost-free, bright and cool place is ideal. Targeted cuts and guy wires help with the design.
Design options
The cork oak primarily allows upright bonsai forms, in which the strong-growing main trunk appears particularly stable. These can be created through targeted pruning without having to resort to the wire. If the tree has developed thick branches that you want to redirect, corrections with guy wires prove to be useful.
Cutting
The evergreen tree can be pruned from February or March. Regularly reduce shoots to one or two leaves throughout the season. If the focus is on growth in thickness, leave the foliage on the branches. When the desired circumference has been reached, grab the scissors.
Wiring
Young branches tend to grow steeply upwards. These can be tensioned and redirected to an angle of 45 degrees or a horizontal direction of growth. A branch clamp (€13.00 at Amazon) for bonsais is equally suitable for creating bends in the branches.
Location
Between spring and autumn, the Quercus species prefers an outdoor location, where it loves full sun conditions. Wind and rain are no problem.
Winter
The tree can tolerate light frost down to minus five degrees for a short time without suffering any damage. However, it is recommended that you place it in a bright and frost-free place in good time. Since the plant is evergreen, it needs sufficient light and mild temperatures even in winter. The thermometer in the winter quarters should not rise above ten degrees.
Care measures
The cork oak has similar care requirements to most trees that are cultivated as bonsai. Due to the limited conditions in the planting bowl, you must continually monitor the water and nutrient supply.
Repotting
Young cork oaks get new substrate every two years. As part of this measure, reduce the root ball by a third. In this way you stimulate the tree to form fresh roots and give it new strength. During the next growing season it benefits from the nutrients that the replaced soil mass brings with it.
Ideal substrate composition:
- 40 percent Akadama soil
- 40 percent pumice or lava granules
- 20 percent soil for outdoor bonsais
Pouring
In summer, Quercus suber has a high water requirement, which you have to meet regularly. Check the substrate surface weekly. As soon as this has dried out, the mini tree requires thorough watering. In the cold season, reduce the intensity of watering as the soil dries more slowly. Do not allow the wood to dry out at any time.
Fertilize
From April onwards, fertilization every three weeks makes sense. Stop this measure at the end of August so that the miniature oak goes into the dormant phase. To harden yourself against the winter cold, we recommend an autumn fertilizer that you spread on the surface of the soil.
