Trees For L.A. 's Future

Since the massive irrigation systems here in Southern California were installed allowing people to plant almost anything with no thought to its environmental impact, many trees that normally would not grow here have been planted. This has lead to our current dilemma where these usually well watered trees are failing due to the massive drought we are  currently experiencing. What are the alternatives? What trees can we plant in the future that take into account the reality of our water resources? Here's a few: 

Crepe Myrtle (Lagerstroemia indica)

Even though this Taiwanese native is under attack from several new pests it is still a very hardy, non-thirsty, and colorful climate appropriate small flowering tree. 

Grevillea 'Moonlight'

Though classed as a shrub, this beautiful white flowering shrub can be trained as a small (15 foot) tree. 

Brachychiton rupestris

This hardy native of Australia is stays small (usually no larger than 30 feet) yet makes a big impression with its bottle shaped, water storing base. Not only is it a decent tree, it doubles as an architectural element. You can plant your very own stonehenge. 

Trumpet trees (Handroanthus sp.)

Native to South America, these reliable bloomers are moderate growers and, once established, easy on the water. 

Handroanthus impetiginosa (R), Handroanthus chrysotricha (L)

Handroanthus impetiginosa

Chinese Fringe Tree (Chionanthus retusus) 

These chinese native trees put on a spectacular display in the spring, and once established are easy on the water. 

Silk Floss trees (Ceiba sp.)

Native to South and Central America, these water savers reliably bloom just around world series time. They can get quite large so give them room and their propensity to shed large branches limits their use in areas where that might be a problem. The white species, Ceiba insignis, blooms more frequently than C. speciosa. 

Ceiba speciosa

Ceiba speciosa

White Ceiba insignis

Ceiba insignis lit up at night with a health light. 

 Desert Museum Palo Verde

This hardy Southwest native does well in inland valleys here; not so well in coastal areas. 

Callistemon viminalis

The weeping bottlebrush tree is vastly underappreciated. It's low water use and blooms for 2-3 months of the year. 

Arboretum senior biologist Jim Henrich admires a Callistemon viminalis. 

What's Blooming at the L.A. Arboretum and Botanic Garden, October 14th 2016

Ceiba (form. Chorisia) speciosa

Floss-silk trees as they are commonly known can be highly variable as to when they start blooming, but since I've been here (1998) they have always been consistently blooming when the World Series comes around.  In the photo below you will see at least two of the four varieties that the Arboretum introduced around the early 1980's; September Splendor and Arcadia. 

Left to right: September splendor, Arcadia

Ceiba speciosa 'Arcadia'

Tabebuia avellanedae var. paulensis 

Identified here as Tabebuia impetiginosa 'Paulensis', this seems a miniature version of Handroanthus impetiginosa. It usually blooms several months earlier than the latter and its blooms can be far more dense. For more info on these beautiful trees see Matt Ritter's article in Pacific Horticulture. 

Tabebuia avellanedae var. paulensis

Pallenis maritima the 'Gold Coin' plant

Pallenis maritima the 'Gold Coin' plant

This tough, salt resistant native to the Canary Islands and the west Atlantic coast of southern Europe and northern Africa blooms Spring and Fall and in between.

For locations of the plants mentioned above and more currently blooming plants check out this map of blooming plants here at the Arboretum (you can use the share feature below to email the map to you smart phone and use it to navigate to the plants):