Why Do Leaves Fall Off Trees: An Explanation

Driving through an autumn forest is one of nature’s most exquisite pleasures. The fierce colors draw the eye and give a sense of wonder every year. Shortly after this spectacular sight, the leaves drop to reveal the stark naked trees of winter. 

Why do leaves fall off trees? Why don’t all leaf types drop? 

Leaves, like all natural things, have a life cycle. The parent tree births them, matures them into full-sized leaves, and the leaves wither away until death. Breaking down this life cycle into seasons simplifies it. 

Preparing for the tree’s seasonal cycle can be a hassle. A professional Clovis tree service company will help with pruning, planting, and branch removal during the appropriate seasons. 

Spring and the Growth of the Leaf Stem

Spring encourages the growth of the leaf stem. The leaf forms its shape and size, growing to maturity. It starts as a bud, creates a stem, then unfolds to its full extent. 

There are two main categories of trees into which every type falls. Both deciduous and evergreen trees lose their leaves, but deciduous trees follow the seasons. 

Evergreen trees lose their leaves as they age, independent of seasonal changes. Some evergreen leaves last as long as two years. 

Summer and the Main Function of Tree Leaves

Leaves absorb the maximum amount of sunlight during the summer months. Trees use photosynthesis to produce carbohydrates and sugars from this sunlight. 

Chlorophyll, the chemical that makes leaves green, helps the leaves absorb sunlight. Sunlight, along with water and carbon dioxide, turns into the carbohydrates and sugars the tree requires for survival. 

Autumn, the Time of Mass Leaf Drop 

Why do leaves fall off trees in autumn? 

The tree saves up its food and feasts during the summer months. As the sunlight fades, the tree’s ability to create food lessens. The leaves outlive their usefulness, and the tree cuts them off from its primary energy source. 

Leaves change color at this time because the tree stops producing chlorophyll during the cooler months. Producing chlorophyll requires vast amounts of energy. With little return, the tree cuts its losses to conserve energy. 

A leaf’s true colors are the vivid reds, yellows, and oranges shown in autumn leaves. These colors stay hidden throughout the year, covered by the chlorophyll’s green pigments.

Winter, the Season of Dead Leaves 

Once the leaves lose their usefulness, the tree hibernates. This hibernation saves energy, allowing a tree to survive for many years. Dropping the dying leaves is key to helping the tree save energy.

A leaf saps away the tree’s resources when left on the tree. While it’s common to rake away leaves immediately, it’s beneficial to leave them be. The dead leaves turn into compost, further strengthening the tree’s life and giving it energy for the new year. 


The year starts again with newly budding leaves, and the cycle continues. A tree’s lifespan depends on the type of tree, but most trees go through this cycle for decades and even centuries. Soil health, temperature, climate, and elevation are key factors to determining a tree’s lifetime.

Asking “why do leaves fall off trees?” is crucial to understanding a tree’s lifespan in-depth. Learn whether a tree can survive a lightning strike for more information on tree health and longevity.  

Handling the seasonal changes of a tree is challenging if you’re unprepared. To invest in your trees’ health and your property’s appearance, reach out to a reliable, licensed, and insured tree service company. Call Cut Rite Tree Service in Fresno, CA  at (559) 320-7723 for a free estimate.


We are a locally owned company that prides ourselves in providing the best service possible for the residents of Fresno, Clovis, Madera, Sanger, Folwer, Reedley and the surrounding areas.

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1806 N Temperance
Fresno, CA 93727 



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