Nature & Garden
Why do leaves change colour in autumn?
A little collection of colours rests on a tree stump.
The short answer
In autumn many deciduous trees break down green leaf pigment. Yellow and orange pigments already in the leaves become visible. Some leaves also produce red pigments.
An imagined Wusel scene
Puschel and Flauschi investigate
Fallen leaves rest on a stump. Puschel arranges green beside yellow and orange. Puschel“The tree has tipped out its paint box!”
Flauschi“A lovely idea. But the pigments inside the leaf are changing.” She gently turns a fallen leaf over.
Puschel“Was the yellow hiding before?” Flauschi“Often it was already there. When the green pigment breaks down, we can see other colours better.”
They look at the tree and then a green hedge. Puschel“They do not all have the same autumn plan.”
Flauschi nods. They put the leaves back on the stump. Their colour collection stays outdoors where they found it.
Discovery 1
Many deciduous trees break down their green leaf pigment in autumn. It is called chlorophyll and helps the plant use light to make food.
Source: [1]
Discovery 2
Yellow and orange pigments are often already in the leaf. As green fades, they become easier to see. Some species also make red pigments.
Source: [1]
Discovery 3
Not all trees change colour alike. Tree species and weather affect the colours. Many deciduous trees later drop their leaves; other plants remain green in winter.
Source: [1]
Little Wusel quiz
Where does visible yellow in many autumn leaves come from?
Choose one answer: a), b).
- a)It is always made entirely from scratch in autumn.
- b)It was often already there and is more visible without green.
Show answer
Correct answer: b): It was often already there and is more visible without green. Yellow pigments were often already present.
Do all trees become equally colourful in autumn?
Choose one answer: a), b).
- a)No.
- b)Yes.
Show answer
Correct answer: a): No. No. Species and weather matter. Some plants stay green.
Word help
- chlorophyll
- The green pigment that helps leaves use light.
Explore in more detail
Here you will find longer explanations and further details. You can explore them together.
Understand step by step
How it works – simply explained
Green pigment breaks down
Chlorophyll helps leaves use light. Many deciduous trees break it down in autumn, reducing visible green.
Other colours emerge
Yellow and orange pigments often already existed and become easier to see. Some trees also make red pigments.
Not all leaves follow one sequence
Species and weather affect the process. Many trees later shed leaves. A sequence does not mean every leaf turns yellow and then red.
References for this explanation: [1]