Benefits of Rain For California Gardens

Part 3 in the GardenZeus series “Gardening Tips for Rain and Rainstorms”

How does rain compare with water from your hose? Rain is much better for plants. Rainwater carries traces of airborne pollutants, but is free of the minerals, chlorine, and chloramines that many cities add to municipal water.

Chlorine is put into city water to kill or prevent growth of microbes, algae, and plants. These life forms are clearly not desirable inside city water pipes, but they are critically important to healthy soil and landscapes. GardenZeus expert Darren Butler believes that saturating our landscapes and gardens constantly in chlorinated city water is devastating to soil life and tends to result in the often diseased, pest-ridden landscapes that we consider normal.

Rain in California is acidic, but generally less so than elsewhere in the United States. While acid rain is harmful to sensitive natural areas in California, particularly lakes and waterways, it actually may help to mildly or temporarily counteract the alkaline soils that are common in populated areas throughout the state, to the benefit of cultivated plants.

Most garden-and-landscape plants thrive during and after periods of heavy winter rains that saturate soils and flush salts to subsoil. Exceptions may include plants or trees in soils infected with pathogens that thrive under wet conditions; plants in compacted soils that go anaerobic after rains; and succulents and cacti or even some California native species if the storms and periods of soil saturation last too long or soil doesn’t drain well.

Even brief rainstorms clean dust and pollutants off of plant leaves. This allows for improved photosynthesis, making it easier for plants to feed themselves optimally with sunlight, for the plants to be as healthy as possible, and for plants to increase production of the oxygen that we need to survive.

Have you ever enjoyed the clean, crisp air on the first day sunny day after a rainstorm? Breathing can be a new and different experience after rain, especially in large California cities with severe air pollution. Much of this may be the result of ionization and the rain having cleaned air pollutants, but it is also a gift from thousands of plants, and perhaps hundreds of thousands of blades of grass in local suburban areas, all with newly cleaned leaves that are photosynthesizing more efficiently and producing oxygen more abundantly.

See the other articles in this series:

Part 1: Preparing for Rain in California Gardens

Part 2: California Gardening During Rainstorms: Flush Salts and Avoid Soil Compaction

Part 4: California Gardening After the Storm: What to do When the Sun Comes Out