It has been naturalized in Southern California long enough to seem to be native. California pepper, Schinus molle, is actually endemic to Peru and adjacent arid regions of South America as far south as Central Argentina. Furthermore, although its small pink fruits with hard black seeds are sometimes used for culinary purposes, it is actually not related to black pepper, and is mildly toxic.
California pepper is as at home here as the name implies. Established and naturalized trees can survive on annual rainfall. They are better foliated if watered a few times through summer, and do not mind average landscape irrigation if their soil does not stay too damp. When they are not dropping a few leaves, they are dropping floral frass or dried berries, so their mess is considerable.
Old trees can eventually get forty feet wide, and almost as tall. Young trees grow rather aggressively. Growth slows with maturity. The distended and irregularly structured trunks and main limbs are picturesquely gnarly, with handsomely flaky tan bark. Foliage and outer stems are delightfully pendulous. The pinnately compound leaves are finely textured, and about three to six inches in length.
Climate is why the European larch, Larix decidua, is so rare here. It prefers cooler weather in both winter and summer, and more humidity. Foliage can roast if too exposed through summer. Small trees that are partly sheltered or partly shaded by larger trees have the best color and foliar density. Larch are innately reliant on somewhat regular watering, so are not drought tolerant. The mildly cool weather of autumn is enough to brown the formerly bluish foliage, which falls shortly afterward.
For a tree that is native to the upper elevations of the Rocky Mountains, blue spruce, Picea pungens, does surprisingly well here. It only wants to be watered a bit through summer to compensate for the lack of rain and humidity in chaparral climates. It does not seem to miss a more pronounced chill through winter. Disease and insect infestation are uncommonly noticeable or damaging.
One might surmise that a tree that is resilient enough to be the state tree of Texas is not too discriminating. If it can take the heat and humidity of the Lone Star State, it can make it anywhere! However, pecan, Carya illinoinensis, actually prefers heat and humidity, and is bored with the mild local climate. The nuts and the mess that comes with them are actually less abundant than they would be in the Gulf Coast States. The deciduous foliage is not quite so colorful in autumn.
It is unfortunate that most florists’ cyclamen, Cyclamen persicum, are enjoyed as cool season annuals only through winter, and then discarded as they are replaced by spring annuals. They can actually survive as perennials for several years, with white, red, pink or magenta flowers hovering above their marbled rubbery foliage each winter. Foliage typically stay less than six inches deep.
Even though it can get about fifty feet tall and wide, Italian stone pine, Pinus pinea, often gets planted as a small living Christmas tree into confined urban gardens. It gets so big so fast that it can get to be a serious problem, as well as expensive to remove, before anyone notices. It is really only proportionate to large public spaces such as parks or medians for big boulevards. The bulky trunks typically lean one way or another. The long limbs spread laterally to form an unusually broad and flat-topped canopy.
Of all the popular pittosporums in Western landscapes nowadays, the karo, Pittosporum crassifolium, is certainly not one of the most familiar. It might have been one of the earliest to have been popularized here though. Because of its resiliency to coastal climates, it was a common hedge in San Francisco during the Victorian Period. With minimal watering, it did well farther inland too.
A mature persimmon tree, Diospyros kaki, is often too much of a good thing. The fruit is both big and abundant as it ripens this time of year. Much of the fruit in taller trees is out of reach. Nearly ripened but somewhat firm fruit can be picked and shared with neighbors for a while, but must be picked immediately once completely ripe. Otherwise, it falls and makes a squishy mess that can not be raked up! Nearly ripe fruit ripens easily off the tree. Individual fruits only need to be spread out in a single layer to limit molding.
Not to be confused with the Canadian rock band from the 1970s, this rush, Juncus patens, is native to riparian areas between western Washington and San Diego County. It is also known as the common rush because it is, obviously, the most common species of the genus on the West Coast. It is only occasionally planted intentionally, but more often sneaks into well irrigated landscapes.
Out in rural chaparral regions, where water is scarce, the big and bold California sycamore, Platanus racemosa, somehow seems to find the spots where groundwater is not too far below the surface of the soil. It is technically a riparian tree, that is just as comfortable competing with cottonwoods and willows along forested rivers and floodplains. It eventually get too big and messy for refined urban gardens, but is somewhat popular nonetheless.