Why do leaves fall in autumn?

Every autumn, the leaves turn yellow, turn red, then fall one by one. For a child watching them fly, it's a real riddle. The explanation, though, is very gentle: when the days grow shorter and the cold arrives, the tree settles down to rest for winter. It lets its leaves go, the way we take off our coat to go to sleep. A lovely image of nature's sleep to share in the evening.

A question that comes back every autumn

From the first cool winds, your child notices it: the sidewalk fills with leaves, the trees thin out, the colors change. "Why do the leaves fall?" It's one of those seasonal questions that invite you to observe the world together. It speaks of curiosity, of the wish to understand what changes around them.

No science lecture is needed to answer. A few simple words, a lovely image, and there you go. The falling of the leaves is even a wonderful subject to explore while walking, picking up the prettiest ones, or in the evening, snuggled up warm, while outside nature is getting ready to rest.

The simple explanation: the tree is getting ready to rest

Here's the idea to pass on. During spring and summer, the green leaves are the tree's little cooks: with sunlight, they make the food that helps it grow. But in autumn, the days get shorter and it's colder. There's less sun, so the leaves can no longer do their job as well. The tree understands that winter is coming, and it gently settles down to rest.

To save its strength during the cold season, the tree stops feeding its leaves. They then change color, going from green to yellow, orange and red, then come loose and fall. You can put it like this to your child: "The tree is tidying away its leaves for winter, a bit like we tidy our things before going to sleep. In spring, when the sun comes back, it will grow brand new ones." It's accurate, and it ties nature to a reassuring cycle: it always starts again.

Nature's sleep, a lovely image for bedtime

The falling of the leaves tells a child something precious: everything, in nature, alternates times of activity and times of rest. The tree works in spring and summer, then settles into calm all winter, sheltered, before starting again. This idea echoes the rhythm of bedtime: by day, we run, we play, we learn; in the evening, we slow down and rest so we can begin again tomorrow.

You can turn it into a little story at bedtime: "See, outside, the trees are resting for winter. You too, your body needs to rest tonight to have lots of energy tomorrow." Like the trees, the bears and the marmots settle into calm for the cold season, and many things sleep in nature. It's reassuring to know that you too are part of this great peaceful movement.

If your child worries about the bare trees, you can reassure them: they're neither sick nor sad, they're doing exactly what's needed to get through winter. And not all of them lose their leaves. Fir trees and pines, for example, keep their needles all year, which is why we find them nice and green in the middle of winter. Noticing the difference between the tree that undresses and the fir that stays dressed is another little discovery to make together on a walk, and a lovely way to show that nature has several ways of getting through the cold season.

How to tell it to a child aged 3 to 7?

The secret is to link what they see to a simple, warm image:

1. Start from what they see: "Have you seen all these leaves on the ground?"
2. Give the key in one sentence: "The tree is resting for winter, so it lets its leaves fall."
3. Reassure about the return: "In spring, the sun comes back and it makes new ones."
4. Link it to bedtime: "Just as the trees rest, you too tonight, so you'll be on form tomorrow."

Picking up a few leaves along the way, looking at them, talking about the colors, is also a lovely way to slow down at the end of the day, far from screens. And come evening, a story to listen to, snuggled in bed, gently extends this autumn daydream all the way to sleep.