I recently bought an 8 ft. tall Parkinsonia, and in 3 weeks it looks like it is dying. I planted it in good soil and water it twice a day. It is in full sun. I live in Daytona Beach. Please help.
It sounds like it is in transplant shock. This article will help with that:
https://www.gardeningknowhow.com/plant-problems/environmental/learn-how-to-avoid-and-repair-transplant-shock-in-plants.htm
My parkinsonia blooms like crazy and produces abundant seed pods, but after it blooms, it turns brown, drops its leaves and looks dead. Then after a couple of months, the leaves come back and it blooms again. There is another parkinsonia down the street and it doesn't do that. Please help.
Parkinsonia, Jerusalem thorn, or Mexican palo verde, is one of the toughest plants around. It adapts to desert conditions all over the world, and is considered extremely invasive in Northern Australia. The pattern of flowering, then dropping leaves, then flowering again (it's flowering season is March-April, or September-October) sounds like the plant is so stressed by flowering that it has to go into a kind of dormancy for a few months, when it bounces back and flowers again. The only thing I can think of that would stress it that much -- since drought and poor soil don't bother it -- is too much moisture and/or fertilizer. So why don't you try cutting down on both (if you're using either) and see what happens. If you're not adding moisture or fertilizer, I'd have to speculate that you simply have a peculiar plant. I hope you'll let us know what happens with this one.