What Does Chlorine Do to a Plant?

Chlorine

• Chlorine is important to plant metabolism, affecting water movement within the plant for photosynthesis, according to Stanford University. Although plants sometimes get too much chlorine, too little chlorine is rare because it is abundantly available in nature. Plants take up chlorine from the soil as chloride ions (Cl-).

Chlorine Effects

• Too much chlorine results in plants having brown leaf tips, and, in more extreme cases, leaves may turn yellow and drop from the plant, according to Stanford University.

  Too much chlorine in grass causes progressive streaking on blades toward the main vein between the blade's tip and the point where the blade bends, according to the Alabama Cooperative Extension System.

  Too little chlorine results in plant leaves wilting, turning yellow or bronzing from lack of photosynthesis; excessive branching of lateral roots, which help to provide water and nutrients from the plant; and eventual tissue death.

Fertilizers

• Plants receiving too little chlorine can have their soil supplemented through calcium chloride (CaCl2), ammonium chloride (NH4Cl) or potassium chloride (KCl), according to the University of Missouri Extension. Growers will have to watch for signs of too much fertilization, such as early signs of leaves turning brown at their edges.

Air Pollution

• Plants can be exposed to too much chlorine through air pollution, according to the Alabama Cooperative Extension System. Plants that are near to the stacks of glassmaking factories and refineries can take in excessive amounts of hydrogen chloride and chloride. Incineration, scrap-burning and spillage, such as from chlorine storage tanks, also emit chloride gases harmful to plants, states the Alabama Cooperative Extension System. Some plants begin to show symptoms after being exposed for 2 hours to certain levels of chloride.

Chlorine and Pathogen Removal

• Seeds are sometimes treated with chlorine to remove bacterial pathogens on their outside coats, to help prevent introduction of diseases in growing crops. Chlorine treatment does not remove pathogens from the inside of seeds.