How do trees grow so tall?

Stand under a big tree and look up. The top can be higher than a house, even higher than a streetlamp! It is hard to believe that this giant once started as a tiny seed. So how does a tree grow up, up, up?

Roots hold it steady

Under the ground, a tree spreads out long roots like fingers. The roots grab the soil and hold the tree tight, so the wind cannot push it over. They also drink up water to feed the whole tree. Strong roots are what let a tree grow tall without tipping.

A trunk made of wood

The tall middle part is the trunk. It is made of hard wood that works like strong bones, holding the branches high in the air. Each year the trunk adds a brand-new ring of wood just under its bark, so it grows a little thicker and stronger.

Reaching for the light

Trees love sunlight. Their leaves use light to make food, so the tree keeps stretching its branches higher to catch more sun. Bit by bit, year after year, it grows taller. A big tree may be older than your grandparents — it took many, many years to reach the sky!

Wonder fact: The tallest trees on Earth are giant redwoods, taller than a 30-floor building. Some have been growing for over 2,000 years!