Native to the Mediterranean. Tree with thick, porous and damage-resistant bark. The leaves are stiff, dark green, with a glossy surface.
It has a slow growth rate, making it ideal as a bonsai.
Growing an oak bonsai is a fascinating process that combines the care of the tree with the creative shaping of its form.
Location
The cork oak tree likes lots of sunlight. Place it on the south or west side. In summer, it needs partial shelter from the sun or full shade during hot midday hours.
Temperature regime
The tree prefers warm conditions, but can tolerate light frosts (down to -5 °C). In regions with cold winters, it needs to be protected from frost.
Lighting
Requires about 4 hours of direct sun per day, the rest of the time in partial shade. If the tree is constantly in full shade, very large leaves develop and may begin to die back.
Soil
Should consist of about 60% minerals (Akadama with pumice) and
40% organic material (humus). Drainage is necessary.
Make sure that the soil does not dry out completely.
Watering
Watering regularly once a day, preferred in the morning.
It is important to check the bonsai every morning and evening to detect if it requires watering.
The hotter the weather, the more water the tree will need.
Fertilizers
Needs NPK (nitrogen, phosphorus, potassium) as well as minor nutrients such as calcium, iron, magnesium, zinc, manganese, molybdenum, boron, cobalt, copper, and nickel. Fertilize the plant with these micronutrients as well.
Nitrogen is the main nutrient for growth, but if there is a lot of it, the leaves become deep green, large, and form long internodes.
It is best to apply a balanced fertilizer every 2–4 weeks.
Fertilization can be reduced in the fall and discontinued in the winter.
Repotting
Young trees are to be repotted every 2 to 3 years, old trees every 4 to 5 years in the spring, before active growth begins.
Repotting is necessary on a regular basis, so that the soil is replaced, and the roots are pruned. The root system after these works will work more efficiently.
Shaping and pruning
Carried out in late winter or early spring. Cut the shoots, leaving 2–3 buds on each.
Wire: Use wire to shape the branches. Wrap it carefully so as not to damage the bark. Remove the wire after 6–8 months.
In early spring, pinch the buds at the top of the bonsai to reduce the size of the leaves.
After emerging from winter dormancy, the oak tree throws out long shoots. These shoots contain 7–8 nodes, which can be pruned if the plant does not get enough sun during the day.
Diseases and pests
Pests: scale insects (diaspididae), spider mites, aphids. Use soap solution to control them.
Regularly inspect and clean the bark from dirt to keep it decorative. Remove dry leaves.
