Orange juice is good for people, so it might seem logical to think it would be good for plants as well. However, that is not the case. Orange juice can stunt the growth of plants, so it is best to avoid using it. It will also leave a sticky residue that may attract insects.
The sugars in orange juice can harm plants in several ways. The sugars will make it difficult for plants to absorb water, and can promote the growth of microbes in the soil surrounding the plants. These microbes can compete with the plants for oxygen and minerals, and produce waste products that harm the roots.
Orange juice is acidic. Most plants do best when the soil is around pH 6.5, which is on the alkaline end of the scale.
In 1999, a student at Clarion University grew rye grass from seeds, watering half with orange juice and half with water. Thirty days later, the watered grasses were nearly twice as tall as juiced grasses and were a darker color. In 2001, a student in Crestwood School in St. Louis watered 1-inch plants with a solution of three parts water to one part orange juice. The plants quickly died.
Substances to avoid
In addition to orange juice, you should not use other kinds of fruit juices, milk or soda to water plants. All contain sugar that will harm plants in the same way the sugar in orange juice will.
Ruby Martes has been writing professionally since 1985, specializing in pop culture, quitting smoking and odd bits of trivia. Martes has a Bachelor of Arts in psychology from the University of California, Berkeley, a Master of Arts in English/creative writing from San Francisco State and a Juris Doctor from University of California, Hastings, where she was a law journal editor.