I'm willing to bet that all the healthy ones you would be seeing around San Pedro are the Mexican Palo Verde, Parkinsonia aculeata. They have the same green trunks, vivid yellow flowers in late spring into summer, and wispy foliage, but the true Palo Verde/Cercidium species are a more distinctive tree when you see them side by side. Parkinsonia also does very well up here in the SF Bay Area, where it is common enough. There is still no comparison between one grown in hotter, sunnier situations like more inland valleys away from the coast and the same tree planted in less than full sun and subject to sea breezes off the bay; where they bloom much later in summer because it doesn't get hot, and are more prone to getting attacked by scale and mealybugs. I personally like Mexican Palo Verde trees, because they give that desert look here where we don't have near enough heat for Cercidium. They do have their downsides, however, as they are messy trees, dropping a lot of fine foliage that gets caught up in plants below them, and not good over paving, where the constant rain of debris always needs sweeping up. You can't beat them for the cheery shot of bright yellow, which can completely cover the tree, and the fine textured foliage only casts light shade, is a nice soft light apple green color which contrasts very well with darker foliage, and the smooth green trunks are spectacular. Very fast growing with little water needed, as well, usually topping out at about 18 feet or so in height by across.

HOA has Palos Verde trees that litter my backyard for 1.5 months every year. They resist removal every time I request. I want a product to spray on these huge trees to not kill them, but to prevent blooming in the spring. Any ideas?

I've grown Parkinsonia (Cercidium) florida and praecox from cactusstore.com, but microphylla did not germinate for me. I had trouble with a couple other species from there as well, so it seems to be hit or miss. Maybe some species are inherently more difficult to germinate, or maybe some of their seed is old or improperly collected. Not sure. I love the blue-green color on my florida. -Chris

Palo verde trees do best in gravelly soil with superb drainage. Neither the mulch nor organic matter will provide that. Consider creating a mound with boulders and gravelly soil and planting the tree in that. You don't say where you are, but the kiss of death for a PV tree is to be wet and cold at the same time, hence the need for superb drainage. Give them that and they are bullet-proof.