did some searching and this is what i came up with i am not the author but found it a good read i hope this helps
Most types of soda (irrespective of brand name - Sprite, Coke, Fanta, Mountain Dew etc.) contain a few common elements: carbonated water, flavouring, colouring and sugar. Of course there are a differences in tastes, and chemical composition, but the basics are the same.
So, what is the story surrounding watering plants with soda or sugar water?
Sodas contain a form of glucose (normally corn sugar extract) and sugar water is normally a mixture of water and crystallised sugar (which is again the glucose extracted from sugar cane). This is normally a form of glucose referred to as d-glucose (due to the shape of the molecule).
Plants are able to absorb and assimilate and metabolise d-glucose, so the simple answers would seem like yes, soda and sugar water does help plants grow. In small quantities or dilute concentrations yes; in large or high concentration no, it will eventually kill the plant. In large doses, the sugar changes the water potential in the soil around the plant, preventing water from being absorbed by the the roots (through osmosis).
The first signs would be that the plant wilts as it it not able to absorb enough water to sustain itself. In addition high concentrations of sugar in the soil provide a fertile breeding ground for bacteria and fungi, which would take the first opportunity to attack a damaged or injured plant.
High amounts of calcium (dissolved by the carbonated water) could also be expected to start precipitating at the surface of the soil.
It also obviously depends on the size of the plant and the quantity (and frequency) of soda/ sugar water you are applying.
A Similar Result
Sugar added to the water given to a plant can help the plant grow faster, bigger, greener and taller, because plants have the process of respiration (the opposite of photosynthesis) which needs glucose, which is sugar, and oxygen to help grow. By giving seeds and young plants sugar water, it helps the plant grow to be greener because it is given a double dose of glucose. However, if you give the plant too much sugar water it will kill the plant because it cannot efficiently absorb water from the soil.
I grew tomatoes as an experiment in my science class and I had sugar water as the experiment. One pot had sugar water tomatoes and the other had regular water. In 1 week the sugar water plants had sprouted and were around one inch. The regular plants did not sprout until around the second week. By the end of three months the sugar water plants were around 2 feet tall at least, had buds and were extremely green and healthy. While on the other hand the regular water plants were not a foot tall yet and they had leaves that weren't that green.
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