Every child knows that in autumn the leaves change color and fall off. The trees are bare in winter, only to sprout again in spring. Only conifers stay green in winter. However, there are more trees that do not lose leaves - they are an important style element in garden design.
The hornbeam only sheds its leaves in spring
Why deciduous trees shed their leaves in autumn - and conifers don't
If deciduous trees would keep their often large and thin leaves over the winter, they would freeze to death in the frost. The sensitive foliage has no protection against frost, but must be supplied with water and nutrients by the tree. Basically, the fall of the leaves in autumn serves to protect the tree: if it kept its leaves, it could neither nourish them nor protect them from the cold and would therefore inevitably be damaged. Instead, it pulls the nutrients out of the leaves - which is why the foliage changes color - and then sheds them. Coniferous trees, on the other hand, have developed a different strategy: their leaves, the needles, are very small and also covered with a protective layer of wax. Therefore, they cannot freeze to death in winter and stay on the tree.
Which trees don't lose leaves?
Most conifers, with the exception of the European larch, are therefore evergreen. There are also evergreen deciduous trees, which you can recognize by their very small, thick leaves. A typical example is the boxwood. However, there are other variants in which trees keep their leaves in winter.
Evergreen Trees
Evergreen trees keep their leaves year-round and only replace overaged foliage. Depending on the tree species, the leaves remain on the tree for between three and ten years. In addition to the conifers, there are a few evergreen deciduous trees, which, however, do not belong to the trees. Examples of evergreens are:
- Bamboo (Nandina domestica)
- Cherry laurel (Prunus laurocerasus)
- Firethorn (Pyracantha)
- Holly (Ilex)
- Boxwood (Buxus sempervirens)
Semi-evergreen plants
Semi-evergreens are trees that stay green through mild winters and only shed their leaves in very freezing temperatures. This group includes, for example, the Akebia (Akebia quinata, also climbing cucumber) and the oval-leaved privet (Ligustrum ovalifolium). These species are not trees either, but a climbing plant and a hedge plant.
Wintergreen Trees
Wintergreen plants, on the other hand, keep their leaves (often withered and therefore brown from autumn) and only throw them out when the new leaves shoot out in spring. This group includes some native deciduous trees such as the hornbeam, the oak or the common beech.
tips
Although bamboo can grow several meters high and is often used for hedges, it is botanically a grass and not a woody plant.