A few weeks ago we cut down a purple-leaf cherry plum tree (Prunus cerasifera ‘Krauter Vesuvius’) in the front yard because it had gotten to be too messy. Initially I had considered replacing it with a blue jacaranda (Jacaranda mimosifolia) but after further research I decided against it: As beautiful as the blue jacaranda is, it, too, has a reputation for being messy, always dropping something.
I briefly considered a purple fernleaf acacia (Acacia baileyana ‘Purpurea’) because of its sexy first-purple-then-silver leaves and its bright yellow flowers but some people say its branches become weak over time and break.
Finally it occurred to me that this spot would actually be ideal for one of my favorite trees of all: a palo verde (Parkisonsia sp.). To me, the palo verde (Spanish for “green stick”) is the quintessential desert tree. Its green bark capable of photosynthesis and its tiny leaves optimized to prevent evaporation show how perfectly adapted it is to arid climates.
Palo verde species in front of a motel in Needles, CA
(the “shrub” in the foreground is an ocotillo, Fouquieria splendens)
In the Sonora desert, the palo verde not only provides habitat for birds, it’s a nurse tree for saguaros, sheltering the young cacti from the intense sun in the summer and the cold in the winter. Obviously these facts don’t matter much in our case—the Sacramento Valley is famously devoid of saguaros—but they’re still cool to know.
Palo verde species at the Arizona-Sonora Desert Museum in Tucson.
Who knows, it may even be the ‘Desert Museum’ hybrid!
There are four species of palo verde: Mexican palo verde (Parkinsonia aculeata), blue palo verde (Parkisonia florida), foothill palo verde (Parkinsonia microphylla), palo brea (Parkinsonia praecox), and the lesser known Texas palo verde (Parkinsonia texana). This article gives a good overview of the various varieties. (To clear up some taxonomical confusion, palo verdes used to be in the genus Cercidium, which has now been subsumed into the larger genus Parkinsonia. However, most nurseries still sell palo verdes as Cercidium.)
Mexican palo verde (Parkinsonia aculeata) at the Ruth Bancroft Garden
Each of these species has its unique advantages and disadvantages so choosing the perfect one was going to be difficult. Then I stumbled upon what would become my holy grail: a naturally occurring palo verde hybrid called ‘Desert Museum’. This cross between the Mexican palo verde (Parkinsonia aculeata), the blue palo verde (Parkinsonia florida), and the foothill palo verde (Parkinsonia microphylla) was discovered over 30 years ago by Mark Dimmitt, the directory of natural history at the Arizona-Sonora Desert Museum in Tucson, Arizona. (Read this article to find out more about the history of the ‘Desert Museum’ palo verde.)
The ‘Desert Museum’ hybrid grows to a very manageable 20-25 ft. and combines the best qualities of each of its parents:
- It is cold hardy to 15°F.
- It is a fast grower given enough heat (5-6 ft. per year in the ground).
- It is very drought-tolerant although deep watering in the summer (every two weeks or so) helps it grow faster.
- It has larger and brighter flowers.
- It flowers for a longer period of time (four or five weeks in the spring) and often blooms again in the summer.
- It is thornless.
- Its trunk is a deeper green.
- It can handle clay soils as long as its roots aren’t waterlogged for extended periods of time.
Palo verde as part of a low-water landscaping scheme in Davis
After reading many glowing reviews about ‘Desert Museum’, I decided that it would be the ideal replacement for our cherry plum; my wife agreed whole-heartedly. It felt good to have come to a decision. The most difficult part—the selection process—was now over and the rest was going to be smooth sailing.
It quickly became clear that deciding on a tree is one thing, finding a specimen is another. I first contacted a small family-owned nursery here in Davis, Redwood Barn Nursery. The owner, Don Shor, is a well-known plant expert with a wealth of knowledge. He assured me that palo verdes grow great in our area but unfortunately they are a hard sell (probably because most homeowners are not familiar with them) and none of his suppliers carry them.
Palo verde at Maria’s Cantina in Woodland, 15 miles north of Davis
I then tried Green Acres in Sacramento, the largest retail nursery in the Sacramento Valley. Since they carry Monrovia products and Monrovia has the ‘Desert Museum’ palo verde in their catalog, I was hopeful they might be able to special-order one for me. Unfortunately, the person in charge of ordering never responded to my attempts to reach her (I even left her a note during a personal visit to the nursery).
Calls to other nurseries in our area didn’t go anywhere. None of them carried any variety of palo verde, let alone the one I wanted, and none was able to special-order one.
Palo verde flowers
A web search led me to the Lowe’s web site which lists both the blue palo verde and the ‘Desert Museum’ hybrid. I was thrilled: $37.66 for a 10¼-gallon plant! I called three Lowe’s stores in the area; two were not responsive but the nursery manager at one store told me that this tree would have to be special-ordered from a specific supplier and that they wouldn’t be able to place an order until a certain minimum was reached, which wasn’t likely for many months to come. I do understand the economics, but it’s still extremely frustrating because I bet that just about any Lowe’s store in Phoenix or Tucson has the ‘Desert Museum’ palo verde in stock.
At this point I decided to expand my search to wholesale growers which have ‘Desert Museum’ in their inventory in hopes of getting a referral to a retail nursery that would be willing to place a special order.
Boething Treeland Farms referred me to Green Acres (see above) and to Home Depot. I decided not to follow up on the Home Depot lead, figuring their policy would be the same as Lowe’s.
Village Nurseries, one of the largest plant growers in California, was next. In addition to growing grounds in Northern and Southern California, they also operate five landscape centers (including one in Sacramento) aimed at landscape contractors and other bulk plant buyers. When their rep returned my call, I was mentally prepared for more disappointment. Imagine my surprise when Jeanie, the wonderful lady I spoke with, not only knew what the ‘Desert Museum’ palo verde was (she loves it) but cheerfully told me that they would be happy to have one shipped from their Southern California growing grounds to their Sacramento location. I was so thrilled, I ordered two, one to replace the cherry plum and one to go on the other side of the front yard (it’ll replace the weaver’s bamboo that is too large for its spot). The price: a still reasonable $63.99 for a 15-gallon can.
My two palo verdes are scheduled to arrive in Sacramento tomorrow and will be ready for pickup on Monday. Please keep your fingers crossed that they will actually be there waiting for me!
- Sayonara, cherry plum tree
- Palo verde quest ends in success [this post]
- Happy ending to palo verde saga
- Mesquite and Palo Verde Trees for the Urban Landscape (University of Arizona Cooperative Extension)
- Our State Tree puts on a show in April (University of Arizona Cooperative Extension)
- Palo verde tree called Desert Museum puts on show all summer long (Los Angeles Times)
- Bishop: Desert Museum Palo Verde truly ‘better’ (TucsonCitizen.com)