Q: I need some advice on how to grow royal poinciana trees. The trees I have are babies. I have in the past lost a few I think due to over watering. I have them in different size plastic containers, in cactus, palm, and flower potting soil, in the shade with just a little morning sun.
A: The general recommendation for non-desert tree species is watering once every seven to 10 days in the summer to a depth of 24 to 36 inches. This is, of course, for trees planted in the ground. The frequency would be greater for container trees and really depends on how fast your container dries out. The time it takes for a container to dry out depends on the size of the container and how much exposure it receives. This tree likes the heat and naturally grows in a hot and humid environment. You might need to experiment with your irrigation system and your moisture meter to see how long the soil takes to dry.
The problem with growing this tree in Tucson is the cold since they cannot tolerate a freeze. Prepare for that by finding a protected place for your containers and/or getting some frost cloth to cover them.
Peter L. Warren is the urban horticulture agent for the Pima County Cooperative Extension and the University of Arizona. Email: plwarren@cals. arizona.edu
