What Happens When You Water Plants With Soda?

Dehydration

Plants need sugar for photosynthesis, however, plants do produce enough sugar on their own to support this process. According to Garden.org, adding sugar, by watering a plant with a high-sugar soda on a regular basis, will cause the root system to become dehydrated. The plant will then lose the ability to absorb and distribute water and may wilt suddenly.

Insect Attraction

Many garden insects are attracted to sugar, so watering a plant with soda, which may have a high concentration of sugar, will attract flies, ants or other garden pests. In addition, high concentrations of sugar in the soil around a plant may encourage bacteria or fungus.

Using Club Soda

Unlike regular soda, soda water is a good alternative for watering plants. According to a 2002 Colorado University study, plants watered with soda water grew more quickly and the plant leaves were a "healthier" shade of green. According to the study, soda water provided plants with more macronutrients than tap water.