How does water reach the leaves?« Back to Questions List

Have you ever imagined how does water reach the leaves of a coconut tree or teak tree or what forces them to travel all the way from the roots to the top?


There could be hundreds of feet between the roots and the leaves of a tree. Great volumes of water make this trip at an amazing speed of 100 feet per hour. It all begins at the roots where water moves into root hairs by osmosis. Cells in the root hairs contain dissolved sugars and salts and the water moves into them from the surrounding soil to equalize the pressure. The increase in water pressure at the root hairs forces water upward, cell by cell, through the roots and trunk toward the top of the tree.


water reaches the leaves


This upward motion is still made stronger by one other force. While a tree grows, it passes tons of water into the atmosphere through its leaves by a process called transpiration. Only 1% of the water that is taken in is used during photosynthesis and remaining is lost by transpiration. This creates a partial vacuum that is quickly filled by the water being pushed up from the roots.



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