The Four Biggest Threats to Trees Living in Southern California

In many ways, southern California is an ecological paradise. A wide variety of tree species thrives in the region’s warm climate, including everything from palm trees to redwoods to fig trees. Many homeowners and commercial property managers are keen to take advantage of this fact by planting a nice selection of trees.

However, while southern California is a welcoming habitat for those species well-suited for the local conditions, others will be unable to survive in the region. This means that proper species selection is crucial, as you’ll need to install trees that can withstand the challenges presented by the local environment.

Some of the most important threats facing trees in Long Beach, Beverly Hills, Los Angeles and the surrounding region are detailed below.

1. Drought

Like most other areas that experience a Mediterranean climate, southern California typically receives very little rainfall (if any at all) throughout the summer. While most native species — or those hailing from similar climates in other portions of the world – have evolved adaptations that enable them to withstand the long dry season, many exotics will struggle to survive without supplemental irrigation.

In addition to supplying plants with more water, you can also improve the drought tolerance of a tree by planting it in an area sheltered from the wind and the afternoon sun. Be sure to apply supplemental water on an infrequent, yet thorough basis, which will encourage deeper root development. This will help the tree access water locked deeper in the soil.

2. Wildfire

Wildfire is a perpetual threat for those living in most of California, and that includes the trees. Some of the native species, such as sequoias, have evolved exceptionally thick bark, which protects the delicate living tissues inside the trunk from the searing temperatures of a fire. Other native species have adapted their reproductive strategy to work in conjunction with the regular fire cycle. For example, many trees only release their seeds after exposure to fires. Because the fire has cleared out the vegetation beneath the tree, the new seedlings will not face the competition they normally would.

There isn’t much you can do to protect your trees from wildfire, except to select fire-adapted species and avoid planting them too close together, which will make it more difficult for the fire to jump from one tree to the next. Of course, you’ll also want to avoid planting trees in close proximity to your home, as they can serve as a way for the fire to reach your home.

3. Pollution

Southern California may be beautiful, but thanks to the dense population and thriving industrial sector, the region is one of the more polluted areas in the country. Trees actually help to counteract many of the problems caused by this pollution, such as absorbing harmful gases and reducing the amount of runoff water flowing across the land. However, in the process, many trees become stressed by the pollution and ultimately end up dying.

Fortunately, trees vary in their ability to cope with pollution, and some tend to thrive in polluted cities and suburbs. So, the best way to help ensure your trees don’t begin to suffer from the filth in the local air and water is by selecting a species that tolerates pollution and the urban life well.

4. Invasive Pests

California certainly doesn’t have a monopoly on problems associated with invasive species, but because of our region’s warm climate and the fact that many goods coming from all regions of the globe enter the country here, our local trees often suffer at the hands of introduced pests and pathogens. The Asian citrus psyllid, which is associated with the deadly citrus greening disease, is perhaps the most famous example, but plenty of others exist.

The best way to avoid problems with known invasive pests is by selecting species that are not vulnerable to the pests. Don’t, for example, decide to plant a row of orange trees in the middle of areas overrun with citrus psyllids. It is also possible in many cases to purchase cultivars of normally vulnerable species, which will not be harmed by the pest.

Despite the threats facing the trees of Long Beach, Santa Monica, Beverly Hills or anywhere else in the greater Los Angeles area, many obviously survive. But to give your trees the best chance of surviving, you’ll need to select those species and cultivars that can cope with the challenges common to our area.

If you need some help selecting trees that are likely to thrive in your property – or help to support the trees already planted there – contact your friends at Evergreen Arborist Consultants. We’d be happy to help provide actionable advice that will give your trees the best chance at living long, healthy lives.