Why non-native plants can be harmful

Can you identify invasive non-native plants in the wild? In 2007, “Marin Flora” reported that Marin County has 1,045 native plants and 583 introduced ones. Some of these introduced species are considered to be invasive. We are all familiar with invasives like French broom, which seems to be everywhere. Less familiar are the non-natives like forget-me-nots, filaree, rattlesnake grass, bellardia and montbretia.

The California Invasive Plant Inventory categorizes plants that threaten the state’s wildlands. French broom has a “high” rating with severe ecological impacts; these latter ones have a “limited” rating with minor ecological impact.

The ecological impact may be the crowding out of natives by invasives, which reduces biodiversity. Non-native invasives may also negatively affect crops, waterways and soil.

— katie martin, UC Marin Master Gardeners