California, home to 4,200 native plants, has 200 invasive plants trying to choke them out of existence. While the California Invasive Plant Inventory tries to educate and inform the gardening public about these plants, they are still planted in landscapes today. Learning how plants that are invasive work is one way to learn how to stop them. Always pick native plants over invasive species to plant in any garden.
The Calla lily, Zantedeschia aethiopica, is listed as an invasive plant in California (Cal-IPC inventory rating of Limited). It is a perennial that grows around the coast of northern and southern California and in the San Francisco Bay. While most gardeners grow this lily as a garden plant to decorate their landscape, the invasiveness comes from prairies and the wetlands. Propagation of the calla lily is through seeds and through rhizomes.
The scarlet wisteria, Sesbania punicea, is also known as red sesbania and is classified as invasive in California (Cal-IPC inventory rating of High). It is a shrub that is deciduous and found in the Central Valley riparian section of the state, choking the access spots to the river. It has also been named as a cause of erosion, flooding and eradicating some native plants from the area.
Canary Island Date Palm
The Canary Island date palm, Phoenix canariensis, is classified as an invasive in the state of California (Cal-IPC inventory rating of Limited). It is a tree that has started to cluster form in southern California. It is an invader of stream corridors and has such a dense canopy in its form that it is choking out native plant growth. Orchards are also affected by the widespread growth of this date palm.
Soft brome, Bromus hordeaceus, is classified as a California invasive plant (Cal-IPC inventory rating of Limited). It is a grass that takes over the land that has low fertility and will out-compete with native grasses in the same area. It can spread wildly and hedge out some rare plant species with its rapid growth.
Giant dracaena, Cordyline australis, is also known as the New Zealand cabbage tree and is a California invasive plant (Cal-IPC inventory rating of Limited). It is growing in forests of Salt Point State Park and Redwood National Park. What started as an ornamental tree in the landscape is now infesting through birds distributing seeds.
Halogeton, Halogeton glomeratus, is an invasive plant in California (Cal-IPC inventory rating of Moderate). It is an annual that can be seen throughout the state in salt grass or desert shrubs. It is invading disturbed sites so that it can prevent more desirable native plants from growing. Not only invasive, it is toxic to livestock.