- Author: Jenni Dodini
Published on: October 14, 2021
Greetings from Borrego Springs. Seemed like we should get out of the Northern California heat, so we headed to the desert in southern CA. Borrego Springs is located between San Diego and the Salton Sea in a valley in the high desert. Contrary to its name, there are no springs. The water source is solely due to the underground aquifers. There are some hot springs in Agua Caliente, which are not far from here. As this is the low season, many of the tourist areas are closed, so there are not too many people here. The tourist season starts up again in late October. We have been down here in January, and it is a really nice getaway, but may have rain then. (One can only hope.)
Anyway, I really like coming to the desert. Don't think that I like it enough to live here permanently, but do enjoy it when I'm here. One thing I love is how different the vegetation is from home. That being said, a particular favorite is the Palo Verde trees. The Spanish translation means "green stick" for their green-colored branches. There are three types of Parkinsonia and they are a member of the Fabaceae family (yes, PEAS!) The most common is the P. florida in the southwestern U.S. The other is the P. aculeata, which is common in the Sonoran desert and foothills in northwestern Mexico. The third is a foothill variety called P. microphylla. It is more common in Mexico. THEN... there is a cultivar called "Desert Museum" which has no thorns and grows more upright than the others.
These trees are very fast-growing and can live 100 to 400 years! They grow in fine, fast-draining soil, primarily in washes. They are considered the most drought tolerant of all the deciduous trees and adapt to the environment by growing slower and more shrub-like when there is less water. They also drop their leaves in the hot season and even drop their stems in a prolonged drought. Once established, they can survive on little to no water for prolonged periods. They grow best in hot, dry climates, in full sun, and tolerate the cold down to 15 degrees F. (Sounds like the perfect desert tree.) They propagate from seeds produced during a short flowering season. One reference that I read said that even though they generally flower in the spring, they may flower at other times, depending on the weather in the area. I found this reference after I found the flower in the attached picture. The seed pods really resemble pea pods too. The seeds are very hard and require scoring and soaking to get them to germinate. The flowers attract all kinds of pollinators and are a food source to native birds and animals. They provide a protective canopy for the slow-growing saguaro cacti, which generally outlive the tree!
Now for the ONE thing that truly makes them unique. When they drop their leaves, they photosynthesize through their green bark!
I wondered why it is called "Blue" when the tree is actually green, but I couldn't find any explanations in the references. Pretty much all the references were from Tucson publications, but online, you can find plenty of sales info and pretty pictures. I know that I will never be planting one in my yard as it would not tolerate the soggy soil of our winters, so I guess I will have to continue heading to the desert to enjoy them.