Weather Insider: Warming Planting Zones

It’s no secret that temperatures across the globe are warming as a direct result of climate change. Heat-trapping pollutants in the atmosphere are causing the planet to warm. This is causing plant hardiness zones to shift north, impacting what kinds of plants can be grown where. Plant hardiness zones are based on the coldest annual temperatures experienced by a given area. The map below shows us plant zones throughout southern and central California. While the complex geography of the Golden State has a big impact on local temperatures, by in large, we can see plant hardiness zones decrease as we move north.

Here in the Coachella Valley, we have a plant hardiness zone of 9a. This corresponds to an annual low temperature of between 20 and 25 degrees Fahrenheit. This is based on the climatological average and doesn’t necessarily mean we will actually see those temperatures every year. By the middle of the century, we are likely to transition to a zone of 9b, which corresponds to annual lows of between 25 and 30 degrees. This could impact local farmers by changing when certain plants need to be planted. For instance, if a crop is normally planted in October, it may need to be planted in August or September in the future.