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There was a time when I thought native plants were the best for our landscapes.
They were, regrettably, not the most attractive or commercially available
specimens. But it made sense, in some perversely logical fashion,
to believe a landscape would be most likely to endure if it consisted of
plants native to that particular region.
After all, if it had evolved in that zone, with its unique combination
of soils and climate, what could go wrong? For one, pests who evolved
with it and were able to evade its chemical defenses, would cause problems.
Thus, the few insects who can eat the leaves of Texas Mountain Laurel and
also not succumb to the toxic brew of alkaloids they contain, will defoliate
them if insecticides are not used.
While such defoliation has not killed a Texas Mountain Laurel in nature,
it will render it unsightly. Levels of herbivore predation which
are not life-threatening can ruin the visual appeal and landscape usefulness
of a native plant. Even though some pesticides would be needed periodically
in a landscape of indigenous plants, I still thought they were superior.
I rationalized that the sprayings were merely needed for cosmetic, not
vital, reasons.
Then came the real estate crash of the mid- to late-eighties. Foreclosed
properties were everywhere. Their landscapes received no or minimal
irrigation, fertilization or maintenance. Did the non-native plants
dry up and blow away? They didn't! Even after a dry summer
with no irrigation, the alien flora stayed green. The Asian Jasmine,
Chinese Photinia, Oleander, Cotoneaster, Pomegranate, Holly, Palms, India
Hawthorn, Bamboo, Loquat, Nandina, Pittosporum, Xylosma and others refused
to die.
Of course, some did not look too good. But the scorched and weakened
specimens were usually in beds with thin soils and had received no soil
modification by the "landscrapers" who had installed them.
However, where real landscapers had done the installation, or the soils
were originally deeper, all was well.
Thus, one day, I experienced a horticultural epiphany.
The revelation was that Texas native plants were not the only ones that
could persist and possibly naturalize in this area. As long as the
species had evolved in a site with similar soils and climate, and was installed
correctly, it could live with minimal human intervention once well-established.
Plants from China, Korea, parts of Central Asia, the highlands of Mexico
and subtropical Mediterranean climate zones throughout the world could
become transplanted Texans.
Don't let the parochial proponents of xeriscaping and other plant nativists
browbeat you into filling your landscape with ugly and prickly, yet botanically
interesting, things. Forget the gravel and cow skulls and wagonwheels.
Our landscapes can be efficient and regionally appropriate even if they
contain exotics. But do ascertain that those exotics evolved in places
with soils and climate similar to central Texas.
So, let's be right neighborly and say, "Howdy Nandinas! Ya'll are welcome
to stay a spell!" |