Trees – Pasadena Beautiful Foundation

Pasadena Beautiful was founded in 1960 to plant street trees
to enhance the beauty of Pasadena. One of our primary goals continues to be the selection, purchase and planting of street trees. Following the City’s Master Street Tree guidelines, a very dedicated Pasadena Beautiful volunteer, Emina Darakjy hand selects each tree for a specific site. Supervised planting and maintenance by trained professionals ensure a healthy tree canopy for our city.

The beautiful green tree canopies in Pasadena are in small part
an example of our efforts over the last 60 years making it a
special place to live, work and raise a family.

A PBF member represents the organization on the Urban Forestry Advisory Committee (UFAC) board and attends their monthly meeting to advocate for the future care and protection of our urban forest because we want to protect and preserve.

September Tree of the Month

Quercus suber – cork oak
Family: Fagaceae

The cork oak is a member of the Fagaceae family and is native to Southern Europe and Northwestern Africa. The botanical name “Quercus suber” is derived from the Latin words: “Quercus” for oak tree and “suber” for cork.

This is a medium sized evergreen tree that can reach a height of 40-50 feet with a spreading canopy up to 60 feet wide. It can live for more than 200 years.

The trunk is very unusual looking, with a light grayish-brown thick layer of spongy bark with vertical fissures that are white on the outside and reddish brown on the inside. The trunk is the main characteristic feature of this tree.

In some countries like Spain, Portugal and Morocco where very large forests of cork oak exist, this tree is grown for the sole purpose of producing, harvesting and commercially selling cork which is a natural product used to make wine bottle stoppers as well as all types of flooring, insulation, and household articles.

The harvesting of the cork begins when the tree is about 20 years old and continues in intervals of 9 to 10 years. This is done by making a cut to the layer of bark that covers the trunk and stripping it away. This does not kill the tree or cause any damage to it. After the stripping is done the trunk looks smooth and reddish brown then turns darker and starts growing another layer of bark. This process continues for more than 100 years.

The leaves are alternate, ovate, serrated, and glossy dark green on the top. Also, the leaves are very pale gray with distinct hairy veins underneath.

The acorns of the cork oak are oblong with beautiful cream-colored frilly caps that cover as much as one third of the acorns.

Once established the cork oak is considered drought tolerant but can benefit from occasional deep watering. It does well in most types of soil with good drainage and prefers full sun but can tolerate some shade.

The cork oak in California is grown as an ornamental tree, and requires a larger parkway/cutout of 7-feet. It can be planted as a street tree, in a park or in one’s garden with ample space. Damage to the sidewalks from its roots is minimal. Pest to worry about are root diseases, California oak worm and the polyphagous shot hole borer (PSHB).

When using mulch, please make sure to keep it away from the tree trunk and re-direct your sprinkler heads away from the trunk. Using drip irrigation is the preferred solution to watering trees. Lastly, never put decorative arroyo boulders or stones underneath the tree as this tends to cause compaction to the soil and keeps it very moist which is not a good thing for any tree and especially not the oak species.

On a side note, I was fortunate to grow up near one of the largest cork oak forests in the world called the Mamora Forest, outside of Rabat, the Capital of Morocco. I have very fond memories of piling up in the family car every Sunday to go for a picnic underneath these remarkable trees and surrounded by carpets of beautiful flowers.

Article and photos by Emina Darakjy

Tree Request Information for Homeowners:

Typically, when the city is ready to start their planting cycle, they will leave a note to inform the homeowner that they are about to get a tree which is usually a 15-gallon tree. If you prefer a larger tree than the one provided by the city, please inform the city of your preference. The city will then contact Pasadena Beautiful about the homeowner’s request for the upgrade, and PBF will instead provide a 24 in. box size tree.

Please note that the planting site has to be approved and the curb marked by the city after the dead tree is removed and the stump is ground prior to planting a new tree.

Alternatively, as the homeowner, if you want to pay for a larger tree, please email us at [email protected] and include your address and contact information where you can be reached. The cost is $500 and includes the tree, delivery, stakes, ties, trunk guard, slow-release fertilizer, soil amendments, mulch and labor.

Street tree requests should be directed to the 311 call center or (626) 744-3846

Any questions or inquiries regarding urban forest, please call or email:
Michael King
Email: [email protected]
Phone: (626) 744-3846