What Is Photosynthesis?

This fascinating process is the key to life and growth in the garden.

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The energy of the sun is converted into storable chemical energy through the process called photosynthesis.


The energy of the sun is converted into storable chemical energy through the process called photosynthesis.

The energy of the sun is converted into storable chemical energy through the process called photosynthesis.

It’s the ultimate symbiotic relationship. Tending to plants and trees is so much more than a hobby or beloved past time, it is a strategy for survival that affects all humankind and goes well beyond the food it provides. Way to go, gardeners! We’re all stewards contributing to the survival of the human race thanks to photosynthesis. Who knew? 

Most of us are familiar with the concept of photosynthesis, but how does it work? From the Greek words “photo” meaning light and “synthesis,” to assemble, it is the chemical in which plants use energy from sunlight to make their own food and the oxygen we need using carbon dioxide, water and nutrients. Harnessing the energy of sunlight, the formula reads 6CO2 + 6H2O --> C6H12O6 + 6O2. What that means is carbon dioxide and water are converted to storable glucose (sugar)  and oxygen. The plant breathes carbon dioxide and drinks in water. Add sunlight and the conversion takes place in chloroplasts within the plant. Plants use the sugar, we breathe the oxygen. Everybody wins.

Photosynthesis occurs in all plants as well as some bacteria and algae. The trees and plants that cover the land are obvious contributors, but many are surprised to learn that roughly half of the oxygen produced by photosynthesis comes from the ocean by way of phytoplankton, single-celled plants living at the surface, soaking up sunlight and pulling nutrients present in the water instead of soil.

But do plants need animals to survive? While it’s true that animals (us included) produce carbon dioxide through respiration, CO2 is also released by fire and other sources. While CO2 is essential for the photosynthesis that produces the sugars needed to survive, it isn’t the only component. Although plants would survive longer than animals if the symbiotic relationship were broken, many of the plants we know today would fade away without the partnership between plants and animals. 

Animals eat plants and produce fertilizer through both digestion and decay as the organisms die and break down to provide soil with the nutrients plants require to survive. Although some plants self-pollinate or rely on wind distribution, most rely on insects for the process to be successful. Completing the circle that hinges on photosynthesis, but dependent on these related processes, it is a partnership that has endured since life began on this planet and continues uninterrupted. 

The collaboration between plants and animals needed to sustain life spans the Earth and every plant, animal and gardener is a participant. And odds are things will keep rolling along even if you don’t expand the garden this year. As for me, I’m not taking any chances.

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