California Invasive Plant Control
InvasiveEnglish ivy or Algerian ivy
Hedera helix or Hedera caneriensisSome ivy species in the Hedera genus are a problem in California. They can smother understory vegetation, kill trees, and harbor non-native rats and snails. It’s difficult to distinguish problem species from less invasive ones. Do not plant ivy near natural areas, never dispose of ivy cuttings in natural areas, and maintain ivy so it never goes to fruit. Researchers hope to determine which ivies can be planted safely.
Try These InsteadAsian jasmine or ivory star jasmine
Trachelospermum asiaticumEvergreen, vining groundcover up to 20 feet across. Has glossy, dark green leaves and pale yellow, pinwheel-shaped flowers with a jasmine scent.
InvasiveGreen Fountain Grass
Pennisetum setaceumSpreads aggressively by seed into natural areas by wind, water, or vehicles. Fast grower; impedes the growth of locally native plant species and eventually takes over natural areas. Also raises fuel loads and fire frequency in natural areas. Is spreading rapidly in California. Existing research indicates that red varieties of fountain grass (P. setaceum ‘Rubrum’ are not invasive.
Try These InsteadSan Diego Sedge
Carex spissaThis large sedge has a form similar to that of an ornamental grass. Produces gray leaves to five feet tall and yellow, grass-like flowers in the spring. Deer resistant.
InvasiveAcacia, golden wattle, green wattle or western coastal wattle
Acacia cyclops, Acacia dealbata, Acacia decurrens, Acacia melanoxylon or Acacia longifoliaAcacias grow along most of the coast and inland in the central portion of the state. They spread by seed, root, suckers, and stump sprouts, forming dense stands. In southern California, coastal wattle (Acacia cyclops) has invaded many natural areas incluing wetlands and dry hillsides.
Try These InsteadBush Marigold
Tagetes lemmoniiPerennial shrub that can grow up to 6 feet tall. Evergreen leaves with yellow flowers that bloom in winter and spring
InvasiveMexican fan palm or Canary Island date palm
Washingtonia robusta or Phoenix canariensisMost palms are good garden plants, but Mexican fan palm and Canary Island date palm are extremely invasive. In Southern California, they invade wetland areas, crowding out native vegetation. Canary Island date palm seeds are spread by birds. Dense groups of palms with untrimmed fronds harbor rats and snakes and can be a fire hazard.
Try These InsteadPindo palm or Jelly palm
Butia capitataCan grow up to 20 feet tall. Grey-green foliage with red flowers and edible fruits. Tolerates frost, heat, aridity, and poor soils.
InvasiveBrazilian pepper, Peruvian pepper or California pepper
Schinus terebinthifolius or Schinus mollePepper trees are native to South America (despite the fact that Peruvian peppertree is sometimes called California peppertree). Seeds are transported by birds and mammals into natural areas. The aggressive growth of peppers enables them to displace native trees and form dense thickets in natural areas. They produce undesirable suckering and sprout unwanted seedlings. A serious problem in southern California. Less of a problem in the San Francisco Bay Area and Central Valley, but care should be taken if planting near wildlands.
Try These InsteadFern pine
Podocarpus gracilorEvergreen tree 20 to 60 feet tall. Makes an excellent street tree or individual specimen in a park setting. One of the most pest-free trees, able to tolerate a variety of soil conditions and temperatures. Can also be used as a hedge or screen plant. Many species and varieties are available at nurseries.