- Name and species richness
- distribution
- Most common species in Germany
- height and age
- trunk and bark
- root system
- leaves
- blossoms
- fruits and seeds
- propagation
- location and soil
- diseases and pests
- benefit/toxicity
The oak is one of the most important forest trees native to us. For centuries, the tree has been a symbol of strength and perseverance. This is probably one of the reasons why his sheets can be found on coins. How well do you really know this tree?

Name and species richness
Oaks belong to the beech family, their botanical name is Quercus. More than 600 species are gathered under this genus, all of which are more or less different from one another.
distribution
The main distribution area of the oak is the northern hemisphere of the world, where the biodiversity is greatest and it is one of the most important deciduous tree species.
However, some oak species can also be found in North America, Central America, Eurasia and North Africa.
Most common species in Germany
There are around 30 oak species in Germany. The leader - measured by the extent of distribution - is the pedunculate oak, which is also known as the German oak. Other important types are:
- downy oak
- swamp oak
- sessile oak
- Turkey oak
height and age
The oak can grow up to 40 m high and 1000 years old. But these are peak values that are not achieved by every tree and not by every species. The pedunculate oaks and sessile oaks that are widespread in this country reach an old age of up to 800 years and develop into stately trees under ideal conditions.
trunk and bark
The trunk of the oak grows stronger over the years and can reach a circumference of up to 8 m. However, there are also significant differences between the individual oak species, which are also reflected in their shape. Some grow straight, others crooked.
The bark is thin and light colored when young. Over the years, the color darkens until it has reached a shade of brown. Then the bark has long since turned into a thick and cracked bark.
root system
The oak forms strong taproots that penetrate deep into the soil. They can reach a length of up to 40 m. This means that the root system can be as powerful as the crown of the tree. That is why the oak is also considered to be storm-proof. The root system is supplemented by finer roots that spread out.
leaves
The leaves of the oak sprout each year. We do this between April and June, depending on the weather. The leaves of all oak species have so-called indentations, apart from that they all look something different.
- they come in different shades of green
- Length and shape vary
blossoms
The blossoms of the oak appear after about 60 years and then at an interval of 2 to 7 years. The flower buds sprout at the same time as the leaves. Both male and female can be admired on each oak tree.
- male flowers are on pendulous catkins 2-4 cm long
- female flowers are smaller and button-shaped
fruits and seeds
The fruits of the oaks are the acorns that we find under the tree in autumn. Inside each of them is one or occasionally two seeds.
The fruits can be fed to pigs, while other livestock are less tolerant of them. In the past, they were used to make a coffee substitute and acorn bread. Of course, they are also a wonderful handicraft material for children.
propagation
The fallen acorn remains viable for about six months. Anyone can grow their own oak from this. In the spring, an undamaged specimen is planted in a pot to develop a new tree.
location and soil
The oak is a light tree that does not like shady places. When it comes to the ideal floor, the adaptable oak does not make any great demands. However, it should definitely be loose so that your taproot can make its way into the depths more easily.
diseases and pests
Diseases common to oak trees:
- oak firesponge
- oak powdery mildew
- cancer
- bark burn
The most common types of pests are:
- Green oak moths
- Common Frostmouse
- oak processionary moth
- gypsy moth
- oak jewel beetle
benefit/toxicity
Oak wood is strong and durable, making it an important commodity. Furniture is mainly made from it.
The leaves and fruit of the oak are not poisonous but are very bitter. For this reason, the bitter substances are first removed from the acorns before they are used in the kitchen as oak flour.