Coconut palms in California

There have been only a few instances of coconut palms growing in the state of California, with the most well-known formerly located in Newport Beach, being a popular attraction for gardening enthusiasts. However, others have been reported in La Quinta and near the Salton Sea.

Background
Coconut palms are not well-adapted to the Californian climate, with the coldness of the soil during the winter and the rain during that season significantly hindering their growth. Places in California that have the appropriate winter temperatures for the trees do not have high enough summer temperatures, weakening the palm due to the lack of sugar it can produce.

Newport Beach palm
The dwarfed palm in Newport Beach was the northernmost outdoor coconut palm in the world and was planted in 1984, by a prior tenant of the building it stood by. It was located off California State Route 1 and almost touched the sidewalk. It was discovered in 1981 by the International Palm Society members Bill Dickenson and Ralph Velez, who reached out to the business owners and informed them of its unusuality. The owners then contacted their gardeners and gave them specific instructions for the care of the tree. At one point, the tree started to develop the typical lean that the species commonly has, fostering concerns that the bend would bring it too far over the sidewalk. To solve this, Dickenson created a sling and wrapped it around the trunk, which, over time, pulled the tree back in the direction of the building. A small plaque accompanied the tree. The palm disappeared in 2015, with the reason why exactly being unknown.

A conflicting report states that the northernmost palm is in the Orto botanico di Palermo in Italy, although it may be a myth due to the absence of photos of the tree. There has also been some conversation about a palm in Funchal in Madeira Island, which has a similar latitude.

Other palms
A coconut palm was reported to be in an outdoor courtyard in La Quinta, being tall enough to be able to be seen from the street. It was transported from Hawaii. Some short-lived trees were also grown near the Salton Sea.

It appears that the slightly inland areas of Southern California may offer more favorable conditions than the coastline. In addition to the ones mentioned above, there have also been videos of palms in Santa Ana and Del Mar.