Hospital oaks only thrive in our latitudes if they find the right climatic conditions. Planting in containers is recommended instead of planting outdoors.
The holm oak belongs to the beech family and comes from the same plant species as the cork oak. Holm oaks can grow into imposing and bizarrely bony trees. However, this happens mainly in the Mediterranean area, because the plants are only partially hardy. In Germany, keeping them in buckets is an alternative. The original growth form of the holm oak is also very popular in bonsai culture. With the planting you lay the foundation for a he althy development of the plants. What needs to be considered here can be read below.
Plant description of the holm oak
The holm oak also has the nickname green oak, because the trees are evergreen, so they do not lose their leaves in autumn like the conventional German oak. Future generations will also be able to enjoy the planting of a holm oak, because the beech family can reach a biblical age of almost 500 years. However, this is less true of the container plant. But if you are lucky enough to live in a climatically favorable region, such as the wine-growing regions in south-west Germany, you can definitely try and cultivate the holm oak outdoors.
The holm oak develops a wide and arched crown and can also grow with multiple trunks. The growth height is different and is 5 to 20 meters. Under particularly favorable circumstances, holm oaks will also grow almost 30 meters in height.
The trunk diameter reaches around 1.5 meters. The young leaves are silver-white in color, changing from pale yellow to a deep dark green. The leaves can grow up to ten centimeters long and have a hairy stem up to two centimeters long.
The holm oak blooms between April and May. The light green nuts, up to almost two centimeters long, develop from the flowers. As with the conventional acorn, the fruit is surrounded on one side by a brown, scaly cup. birds orSquirrels spread the acorns.
The distribution area of the holm oak
The home of the holm oak is the Mediterranean climate zone. The plants are increasingly found between the Black Sea coast and the Aegean. Increased occurrences also occur between Morocco and Tunisia. Individual deposits are also known on Lake Garda and on the Atlantic coast of France. Holm oaks are a common sight in gardens and parks in the British Isles. The plants survive the mild winters and are also found in the wild there. In Germany, holm oaks are only rarely cultivated outdoors. In terms of climate, planting is only recommended near Lake Constance or in the Weser-Ems area and the Rheingraben. The dwarf kermes oak is increasingly pushing the holm oak out of its natural range.
The use of the holm oak
The wood of the holm oak is particularly hard and is used to make furniture. Holm oak wood can also be burned very well, even if it is not yet completely dry.
The nuts are edible and can be eaten cooked or eaten raw. The taste can vary between sweet and bitter. Oil can also be obtained from the seeds. In the Pyrenees, the acorns are fed to the Iberian pigs, which ultimately gives the Iberian ham its unmistakable aroma.
What types of holm oaks are there?
Two subspecies of the holm oak are known:
- Quercus ilex ilex
- Quercus ilex rotundifolia
Differences can be seen in the leaves and petioles. Querus ilex ilex is a widespread form of the holm oak. The trees grow along the coast of the Iberian Peninsula. The distribution area of Quercus ilex rotundifolia also extends to southern France, Tunisia, the Balearic Islands and Algeria.
Plant holm oaks in tubs - find the right location
Since the holm oaks are mostly kept in tubs in our latitudes, the question of location is not a problem. Anyone who notices that their plant is not developing as desired and is beginning to get sick will first change their location. Which is easily possible with a container plant.
➔ Tip: The holm oak grows rather slowly. Therefore it can be planted well in the tub.
The plants come from the Mediterranean region and therefore need a lot of sunshine. The location should therefore be bright and warm. The trees also thrive in semi-shade. The location can be breezybe chosen because the plants are less sensitive to wind.
➔ Tip: To make it easier to move the potted plants to any location, they should be placed on a plant stand with castors.
Which location is ideal for outdoor planting?
If you decide to plant outdoors, it is important to remember not to leave the holm oak in full sun in winter. The winter sun can be very aggressive and damage the bark of the tree. If the bark bursts, it offers pests and fungi an entry point and weakens the plant.
The trees form deep taproots outdoors. When choosing a location, it is important to ensure that there are no pipes and cables nearby that could be damaged by the spreading of the roots.
➔ Tip: Truffles are said to thrive particularly well at the foot of holm oaks.
The ideal substrate for holm oaks
Holm oaks do not like dry and heavy soil. The substrate should always be kept slightly moist. A location near streams or ponds is ideal. The soil should be loosened well before planting. The roots of young plants in particular are very sensitive and need a permeable substrate in order to spread out and absorb sufficient nutrients from the soil.
➔ Tip: Adding gravel or small stones will make the substrate more permeable.
The substrate should not be too sparse and may have a certain amount of clay. Alkaline soils are also tolerated. The holm oak feels less comfortable in pure sandy soil or an excessively loamy substrate. Conventional potting soil is well suited for keeping holm oaks in pots. The substrate can be mixed with gravel or expanded clay. this also ensures a loose soil and prevents waterlogging.
Repot the holm oak
There are a few things to consider when keeping the holm oak in buckets. In order for the plants to develop well, conventional planters will not be sufficient. As already mentioned, the plants form long taproots. Therefore, choose a planter that has an appropriate height. Special care must be taken when transplanting to avoid damaging the taproots.
Repot the holm oak - step by step
- provide new planter
- Prepare substrate
- Lift the plant out of the old container
- Planter with soilfill
- Insert holm oak carefully
- Fill substrate
- Press the bottom well
- Water the plant
- Cultivate plant as usual
➔ Note: If the holm oak is planted in a pot, it can grow about two meters high.