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
After all, if it had evolved
in that zone, with its unique combination of soils and climate, what could
go wrong? For one, pests that 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
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 profound 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!"