Native plant species are also well adapted to local soil conditions, thriving without artificial fertilizers. Additionally, native plant species are generally more resistant to local pests and diseases, although invader pests and diseases may prove problematic. Each native plant species is a member of a community that includes other plants, animals and microorganisms. The natural balance keeps each species in check, allowing it to thrive in conditions to which it has adapted, but preventing it from spreading uncontrolled. Thus, native species rarely become invasive, unlike plants imported from other areas.
Native plants provide food and shelter for birds, butterflies and other desirable wildlife.
Many help to stabilize and hold the soil. Their root systems help rainfall percolate into the soil, reducing erosion and runoff and improving downstream water quality. Many of the hillsides in Southern California suffer from periodic landslides and severe erosion during the winter because imported trees and shrubs have shallow roots which do not anchor the soil on slopes particularly well. Native plant species often have much deeper penetrating root systems which are more effective at holding soil on slopes, often decreasing the possibility of landslides and erosional losses. The diversity of native Southern California plants includes interesting flowers and foliage.