Q: I just noticed your great pruning information in the paper, and I have a question. I planted this palo brea last year, in hopes that over time it would become a tallish beautiful tree that with a high arching branching pattern (surely at a minimum that we can walk under). The info you provided only addresses deciduous trees. I wonder if, when, and how to prune the branches. Also, any suggestion about staking so that it grows pretty straight up, or is that unnecessary?
A: The mature size of the palo brea (Parkinsonia praecox) is 20 to 30 feet tall with an even wider spread so I expect your hope for a beautiful shade tree will be realized in time. It’s hard to tell from your photo but it appears you allowed enough space for this desert specimen to reach mature size without any restrictions.
Because it spreads so wide, it isn’t for every landscape. Pruning shouldn’t be a big deal because it has adequate space. The normal pruning we give to trees to remove damaged, crossing, and rubbing branches should be sufficient. If you need more advice on pruning, please let me know.
Staking is typically done for the first year or so if a newly planted tree requires it. Trees need to be able to sway a bit in the breeze to develop the necessary trunk flare that will support it for many years to come. Staking too tightly and for too long inhibits this development.
Peter L. Warren is the urban horticulture agent for the Pima County Cooperative Extension and the University of Arizona. Questions may be emailed to firstname.lastname@example.org