Many previously “welcomed” urban tree species have outlived their stay, becoming invasive and crowding out other plants in our Southern California landscapes. You can help by avoiding planting these trees identified by various sources (including the California Invasive Plant Council) to be too aggressive and habitat/resource-depleting for further planting.
Invasive Trees to Avoid Planting
Athel (Tamarix aphylla)
Black Locust (Robinia pseudoacacia)
Blackwood Acacia (Acacia melanoxylon)
Brazilian Pepper (Schinus terebinthifolius)
Chinaberry (Melia azedarach)
Chinese Tallow Tree (Triadica sebifera)
English Hawthorn (Crataegus monogyna)
Peruvian Pepper Tree (Schinus molle)
Red Gum (Eucalyptus camaldulensis)
Russian Olive (Elaeagnus angustifolia)
Saltcedar (Tamarix ramosissima, T. gallica, T. chinensis)
Silver Wattle (Acacia dealbata)
Smallflower Tamarisk (Tamarix parviflora)
Tasmanian Bluegum (Eucalyptus globulus)
Plant These Instead
They are drought/heat resistant, low maintenance, and have no known significant pest or disease problems and are not currently overplanted). Find other suggestions here: https://www.cal-ipc.org/solutions/prevention/landscaping/dpp/?region=socal
African Fern Pine (Afrocarpus falcatus) (formerly Podocarpus elatior)
Cascolote (Caesalpinia cacalaco Smoothie®)
Desert Willow ‘Bubba' (Chilopsis linearis)
Fringe Tree (Chionanthus virginicus)
Island Oak (Quercus tomentella)
‘Maverick' Mesquite (Prosopis glandulosa)
Mulga (Acacia aneura)
Netleaf Hackberry (Celtis reticulata)
Pink Chitalpa (x Chitalpa tashkentensis 'Pink Dawn')
‘Red Push' Pistache (Pistacia x ‘Red Push')
Thornless South American Mesquite (Prosopis x Phoenix)