Palo Brea is one of two species of Parkinsonia in the gardens and can be distinguished by its green bark, which is much lighter and almost appears chalky compared to the other Parkinsonia, ‘Desert Museum.’ It is found only adjacent to the Center. On the west side of the Center, it shares a garden bed with Golden Barrel cactus, formally arranged in rows. It is mulched with a contrasting ground, a black lava stone called scoria.
Living up to its name, this “early bloomer” is usually the first tree to bloom in spring. It peaks mid-April and declines by the beginning of summer, unlike its cousin, the darker-barked ‘Desert Museum,’ which has a longer bloom season, stretching beyond the early summer months.
In spring, bright yellow blooms clustered close together create distinctive outlines on its branches. This species, as well as the ‘Desert Museum,’ are crowd-pleasers for humans and pollinators alike.
The gardens are filled with a variety of thorn-less hybrid mesquites. In fact, other than the four Sweet Acacia trees that frame the motor circle in front of the Center, mesquites are the only brown-barked trees in the garden. Their bark colors range from a gray-brown to a deep red-brown and they display a variety of smooth and rough textures.
Mesquites grow naturally as multi-branching trees, which allows them to bend with the strong desert winds. In most of the garden, you will see this multi-trunk growth pattern, but for accessibility in the parking lot and along some paths, they are trained to grow in a single-trunk standard. Whenever possible, natural growth patterns should be encouraged.
As a tribute to Leonore Annenberg, all the trees selected for the Center & Gardens have yellow blooms, one of her favorite colors, and the mesquites are no exception. In the spring, they form dense groupings of yellow tubular flower clusters.
Like many native desert trees, mesquites are legumes, which nourish the desert floor by dropping nitrogen-rich leaves, seedpods, and branches. These fertile grounds offer opportunities for young, fragile plants to get an easier start, but it also means that they require more cleanup.
Their sweet seedpods have been a food staple for humans and native wildlife alike.
There are four Sweet Acacia trees at the Center & Gardens. They are planted in front of the Center, creating four corners of the entry around the motor circle. This design element is a reference to the historic estate, where grapefruit trees in lava stone planters anchor the home’s motor circle.
These trees are most popular during their spring and fall bloom when their flowers fill the air with a sweet aroma. They have been cultivated around the world, but particularly in Cannes and other parts of southern France where their flower’s essential oil is harvested for use in perfumes.
The beauty of their scent is not lost on the pollinators, as this is a bee favorite.
Texas Ebony is easy to spot as it creates the tall hedge that surrounds the Center & Gardens. Its zigzagging branch structure is one of its most interesting features and makes it uniquely striking. Planting locations should be carefully selected as its branches are covered in long, rigid thorns, making it virtually impossible to infiltrate.
Like many desert trees, its leaves are small and glossy, which assist it in reducing water loss through transpiration. In spring, it fills with fragrant, light cream-colored flowers. The woody seedpods that follow the blooms are large and can remain on the tree for up to a year. When mature, the pods twist open to scatter their seeds. Though the pods and seeds can create litter, it is deciduous (leaves shed just once a year) in most places so leaf litter is of less concern.
This striking tree is easily identified by its dark green bark and is one of only two green-barked species in the gardens. It has been planted throughout the east and west gardens, and it encircles the Great Lawn, though not in the planting beds directly adjacent the Center. Those beds belong to its cousin, the lighter green Palo Brea, also a Parkinsonia.
The ‘Desert Museum’ is a complex hybrid with parentage of three other Parkinsonia: the Mexican (P. aculeata), Foothill (P. microphylla), and Blue (P. florida), and inherited traits of all three.
Bright yellow flowers fill the tree’s thorn-less canopy during its long flowering season, which begins in early spring, generally peaking in mid-April, and continuing into the summer. In spring, you will see Costa’s Hummingbirds battling for the best branches to perch and nest and hear the soft buzzing of dozens of delighted bees collecting pollen from this wildlife favorite.