plumeria tree in Sherman Oaks, California

“My question is about tropical plants growing, or trying to grow, in the San Fernando Valley. I have plumeria plants that are growing and flowering nicely, but have no leaves and are basically sticks coming out of the ground. Not very attractive. Can they be turned into prettier plants? And can I plant something around their bases, like petunias, as a ground cover and to add more color?
Also, I have been warned against planting hibiscus here in the Valley, and the two I planted have many yellow leaves and aren’t flowering very much. Is there something special I need to do to make them flower and thrive?
The palms are growing fine. Any other suggestions for plants that will grow well here for a tropical garden feel?”
Christine Medina, Chatsworth
Plumeria plants, whose fragrant blooms are strung together in Hawaiian flower leis, eventually will grow into 15-foot trees.
Your lament about the plumeria’s lack of aesthetic appeal is the secret to its success. Were it enveloped in lush green foliage, it would not be the drought-tolerant, cactus-like garden workhorse that distinguishes it from other fragrant-flowered, but more water-needy, species.
Plumerias are fine with a single weekly soaking until temperatures rise above 90 degrees, at which point they require watering twice a week.
I would not plant petunias, which require water several times a week, around your plumeria. The amount of water needed to keep the petunias happy will kill your plumeria. I would plant the dwarf `Crown of Thorns’ euphorbia around your plumeria instead. This plant shows off red or pink bracts throughout the year and flourishes on a single weekly watering.
The reason you have been warned not to plant hibiscus is probably due to the whitefly insect scourge that has been ravaging this plant throughout Southern California for more than a decade. I have found the yellow and orange varieties to be less whitefly susceptible than the red and pink varieties, and that the problem is more severe in the San Fernando Valley than in the Santa Clarita Valley. As you go north, the colder winters appear to keep down whitefly populations.
The yellow leaves that you see are not a sign that the plants are sick. Being evergreen, hibiscus loses its foliage a little at a time, throughout the year and, before they fall, the leaves turn yellow. Fertilizing with a slow-release product such as Osmocote also is advisable.
Speaking of the palms that you grow, the Mediterranean fan palm (Chamaerops humilis) is highly recommended for Chatsworth, where winter frosts are common. This low-growing, multitrunked species, reaching a height of 20 feet, is the only palm native to Europe and will have no problem surviving bouts of winter cold, even in the Antelope Valley.
The other cold-hardy palm is the Chinese windmill palm (Trachycarpus fortunei), which has a straight trunk that tops out at 30 feet.
There are several gaudy flowering plants that are cold-tolerant and will give your garden the tropical look you seek.
Cannas are herbaceous perennials with banana foliage and large, iris- like blooms. Cannas flower in vivid red, pink, yellow and orange. Some cannas have burgundy foliage, and Canna `Pretoria’ has orange flowers with green- and cream-striped leaves. Canna `Tropicanna’ has orange flowers and purple leaves striped in red, pink, yellow and green.
Angel’s trumpet (Brugmansia) has hanging trumpets in pink, yellow, orange or white that grow up to 12 inches in size. There also is a highly fragrant double white, in which each flower consists of two trumpets, one nested inside the other. A mild fragrance is released by the pendant flowers, which can be found blooming at almost any time. Make sure you give angel’s trumpet a spot in the garden that is protected from wind.
Canary bird bush (Crotalaria) is a garden treasure that most people know nothing about. If you have a passion for bright, silky yellow, bird-like blossoms, you definitely want to get to know this remarkable legume. Canary bird bush flowers throughout the year, but most notably during the summer and fall.
Fig tree control
“I recently planted a `Black Mission’ fig tree.Is there any way to keep this tree dwarf-size, not have it grow to its normal height?”
>Judith Yaniv, West Hills
`Black Mission’ fig trees can grow to 40 feet tall,but may be kept at a height of 10 feet or less by judicious pruning.
After the tree reaches the maximum height you wish it to grow, cut back each year’s growth to two or three basal buds on each shoot.
You can take your horticultural process a step further and make your fig tree into a large bush. Cut back entire stems to ground level once they reach 10 feet in height and 2 inches in diameter. With persistence, you can develop a three-stemmed, vase-shaped fig bush.
It is advisable to wear gloves when pruning fig trees since their sap may produce dermatitis upon contact with the skin.
Tip of the week
If you are interested in exotic plumerias, you will probably want to visit the nursery of Matthew de Caussin in Northridge. There, you will discover a collection of more than 100 plumeria varieties, in a kaleidoscope of colors and fragrances.
Visit de Caussin’s Web site at www.islandplumeria.com, or call him at (818) 970-2483 to schedule a nursery visit.