What is a Plant Community?

Communities are varieties of native plants which support each other in a certain ecosystem or microclimate. They share the same needs for soil pH, water, sun, soil texture and other factors. Planning an area of your garden for plants that share qualities is the best way to arrange your irrigation hydrozones.

 Every plant has a role to play. Some harvest nitrogen from the air and fix it in the soil with the aid of certain soil bacteria. Some have deep tap roots that mine nutrients from deep in the ground and deposit those nutrients onto the soil surface when their leaves die. These also break through hard soils creating passageways for water, nutrients and weaker roots. Some have a fine network of roots that help bind loose soil together to prevent erosion. Others have different purposes such as attracting and feeding our native beneficial insects. Some plant species, in slightly different forms, are found across several of San Diego’s plethora of microclimates.

Many plants in our Southern California communities are very tiny and often short lived, but their quick decomposition provides just enough nutrition to feed the precious soil crust that links the roots of plants together.  Look closely the next time you hike.

If you live near I-5 you will probably be in a coastal sage scrub community. These plants grow in sandy loam that drains well, have salt and humidity tolerance, and are okay with a little extra overcast. Feel safe to plant the small purple daisy with fibrous, soil-holding roots called Beach Aster, the silvery green sprawling and soil-protecting Ashy-Leaf Buckwheat, and the nitrogen-fixing Arroyo Lupine.  Our native beneficial insects depend upon the bright happy yellow flowers of Sunshine Monkeyflower and  Coast Sunflower, and the fragrant purple flowers of Purple  Sage and Aromas Sage.  Here’s a great list of plants for different communities at CalFlora. More plant communities next month!