If you are partial to large panicles of deep yellow flowers, you might also consider the gold medallion tree. It’s an early summer bloomer and proportions are similar to those of hybrid crepe myrtle. Branches do tend to grow rank and wild so it will need to be annually pruned to keep it attractively shaped. Seed pods are a conversation piece as they are deep brown and a foot long, hanging straight down from the tree.
“I have been unable to plant a street tree after the city removed mine about a year and a half ago because I can’t make a decision from the dozens that seem like good choices. Most people in my neighborhood have replaced their trees over the last fifteen years but almost no two trees are the same.
I know it will take decades to full maturity so I may never get the benefit of the shade we desperately need, I just don’t know what deciduous tree will be safest so that roots don’t invade pipes, not leave a sticky mess (like a jacaranda), be relatively fast growing while fairly drought tolerant. When you only get one chance to get it right and only get one tree, how do you make the decision? The following are among the suggestions I have received: carrotwood, camphor, crape myrtle, Himalayan Champaca, western redbud, orchid Bauhinia, and Albizia julibrissin.”
— Melissa Goldberg, Reseda
Let’s examine the suggestions you received for their suitability as street trees. In Los Angeles, when we talk about a street tree we typically mean a tree for a parkway, that strip of ground between sidewalk and street.
I would quickly eliminate orchid trees (Bauhinia spp.) because of their gangly growth habit. This is a genus that resists symmetrical growth and you may find yourself continually staking and re-staking your orchid tree for years to come. The issue here is that its natural growth habit is to send out many trunks but it is typically trained by tree growers into a single trunk specimen. When you fight any plant’s natural growth habit, you are asking for trouble.
I understand the desire to plant a redbud since its late winter pink-magenta bloom is blindingly brilliant, but it just doesn’t make sense for a parkway. The problem with Western redbud (Cercis occcidentalis) is similar to that of the orchid tree. This species, too, grows best when it is allowed to develop a multiplicity of trunks. Unfortunately, the specimens you typically find in nurseries are trained to a single trunk whose bark, when exposed to hot summer sun, invariably cracks. When the redbud is allowed to grow many trunks, its bark does not split.
As for pruning, redbud responds well to coppicing when it ages and starts to thin out. Coppicing is the easiest form of pruning since it involves cutting the entire plant down to ground level. Incidentally, there is an excellent guide to pruning California natives at yerbabuenanursery.com. When you get there, scroll down on the right side until you reach “Basic Pruning . . .” and click.
Carrotwood and Albizia julibrissin, known commonly as mimosa or silk tree, both fall into the messy category. With carrotwood, it’s the seeds that annoy, especially when they fall on your car, if its parked by the curb, and you have to remove their sticky residue. Surface roots on mature trees may also be a trip hazard. As for the silk tree, its sticky flowers are a constant clean-up project when they are in bloom, followed by a litter of seed pods, leaves, and finally leaf stems and twigs when the tree goes dormant in winter. It is a most attractive tree to enjoy due to its wispy pink flowers and fern like foliage, as long as it’s your neighbor’s and not your own. It may also die suddenly, however, from vascular wilt, a disease caused by a fungus that enters the roots.
Champaca, an evergreen (Magnolia/Michelia champaca), has unusually fragrant flowers that place it in a class of its own when it comes to trees. It does grow slowly, however, and is of an undefined shape that you might not call it beautiful. Flowers are for more for fragrance than for looks, and growth is rather dense so it will need to be regularly thinned out once it matures in order to see into the street when backing out of your driveway. Knowing all of this, whether it’s worth waiting for the otherworldly scent of its blossoms — and it really might be — is up to you.
Tip of the Week: Finally, we come to crape myrtle, whose major deficiency is that it is so widely planted that you might consider it boring. However, there is a difference between the conventional crepe myrtles (Lagerstroemia indica) and the hybrids (Lagerstroemia x Fauriei). I was facing the situation you describe almost 30 years ago, decided to plant a hybrid crape myrtle, and have not had any regrets. This is a more robust tree than the regular species. It grows more quickly and is immune to powdery mildew. Flowers are pink, lavender, coral pink, fuchsia, or white, although all cultivars may not be available. All crepe myrtle bark is smooth and mottled and flowering reaches its peak around the 4th of July, after most other trees have bloomed. Roots are manageable and, as for water, crepe myrtle does not need more than a single monthly soaking once it matures. Mature height should not exceed 25 feet.