The disappointment is great when the foliage of a copper beech tree does not live up to the promise of the name. Actually, dark red leaves are the trademark of Fagus sylvatica 'Purpurea'. You can find out why your copper beech tree sometimes has green leaves here.
Why does a copper beech tree have green leaves in summer?
The leaves of a copper beech (Fagus sylvatica 'Purpurea') turn green over the course of the summer because the red pigment anthocyanin is broken down in the cell sap and the green chlorophyll determines the color. This process takes months and leads to seasonal fluctuations in leaf color.
Why does my copper beech have green leaves?
The dark red leaves of a copper beech (Fagus sylvatica 'Purpurea') turn green over the course of the summer because the red pigment anthocyanin gradually breaks down in the cell sap. As a mutation of the common beech (Fagus sylvatica), copper beech lacks a specific enzyme that normally quickly dissolves anthocyanin in young beech leaves. Chlorophyll then gains the upper hand and the foliage turns green. In the case of a purple beech, the process takes place over many months, which can be observed asseasonal fluctuations of leaf coloring:
- Sprout: dark red
- Summer leaves: reddish-greenish
- Autumn color: orange-red to bright yellow
- Winter leaves: reddish brown to dark brown
Tip
Common beech naturally has green leaves
The common beech (Fagus sylvatica) is the only native beech species and parent of the copper beech variety (Fagus sylvatica 'Purpurea'). Their name is an allusion to the reddish wood, as copper beeches have a robe of shiny, dark green leaves. In contrast to copper beech, the cell sap of copper beech leaves contains an enzyme that breaks down the red pigment anthocyanin so quickly that we don't even notice the reddish color of the leaves.
