Pitiful Palm Predicament In Pharr
by K.C. Fletcher
published June 2018
These two Mexican Fan Palms (Washingtonia
robusta) on S. Cage Blvd. in the center
of the City of Pharr are in opposite states of
health. They are an example of the adverse effects
of urbanization upsetting the usually longlived,
free of pest and disease, palm living the
past four decades, majestically lining the South
Cage Blvd. corridor to downtown Pharr.
These RGV non-native palms are now succumbing, area-wide, to an atypical bacteria called a phytoplasm. Lacking the typical bacterial rigid cell wall, phytoplasms must live within the body of, and are spread by, palm frond feeding insects thought to be accidentally imported on palms from Florida. Phytoplasms cannot survive outside of the insect body or the palm's internal passageways that circulate the sugars produced within the palm leaves, properly called fronds, which flows under pressure to all parts of an over ninety foot tall fullgrown specimen.
The native sabal palm (Sabal texensis) may be immune to this introduced disease menace, or much more resistant, time will tell. In general, native plants resist any disease threat, compared to introduced greenery. All palms are classified botanically closest to the grasses. They are tree-like, but definitely not trees. Like all plants, palms are endowed with a genetic potential which can be limited by several environmental factors such as the soil and the fact that roots require access to oxygen from the air trapped between the dirt particles and those same soil spaces containing water. These spaces are termed pores by soil scientists.
Palms do poorly when compaction of the soil permanently reduces or eliminates the soil pore spaces containing water and air trapped between soil particles. The roots metabolically combine oxygen from the air in the soil with the sugar from the palm fronds, high above, to produce energy to power the busy root cells which are constantly multiplying and elongating to drill those absorbing roots throughout the soil on a constant hunt for water and thirteen essential elements. Palms deprived of potassium in the soil can result in outright death, or such a weakened state of defenses that infectious diseases and/or pests may place that palm on a spiral to a slow but certain demise. A high soil pH, caused by leaching calcium hydroxide from concrete, can chemically burn roots and make the surrounding soil more basic, particularly interfering with that palm's requirement of high potassium and magnesium uptake. Covering the base of the palm, where the roots visibly emerge from the trunk at the root initiation zone, and then compacting that soil, eliminating soil pores, decreases oxygen uptake for respiration suffocating those roots.
A downtown Pharr old-timer remembers those good-old-days, over forty-five years ago, when TxDot transplanted those palms, now towering over forty feet tall. They have survived nature-made catastrophies, such as hurricane winds above ground, to apparently succumb to the pure man-made, underhanded destruction of highly corrosive concrete leaking into the underground soil of the root ball mat. This, combined with depriving that palm of vital roots ripped out during demolition for recent curb renovation, and especially the washout of toxic concrete direcly into the rooted soil, all directly contribute to the palm's much too early demise.
Before this downtown, moribund green infrastructure's man made, slow murder at the northeast corner of Pharr City Hall,118 S. Cage, is given the 'coupe de chainsaw', please visit. Raise your hand with the back of your fingers facing towards your face and wave a palm to palm good-bye. The final deep South Texas chainsaw massacre will probably take place in the dead of night.
Until then,'Pharr-thee-well' and a 'frond' farewell, tall friend. Thank you for your beauty, creating a sense of place, destination, history, refuge for wildlife, resting refueling, nesting and, especially, all that oxygen from your friendly fronds. We regrettably apologize to you for your below ground betrayal creating this sad tale of these Two Palms of Pharr!