Neil Sperry shares lessons learned from decades in North Texas horticulture

In my several decades of writing for the Star Telegram my recommendations and suggestions have been fine-tuned and tailored many times over. Put in other words, I’ve learned some important lessons.

One of the first and most difficult was back in the late 70s when we all were searching for a replacement for common St. Augustine — the most popular turfgrass in Texas. A fatal virus called St. Augustine decline, SAD for short, had moved in from the Rio Grande Valley, through San Antonio and across Texas killing St. Augustine in its wake.

There was no preventing its spread, nor was there a cure. However, it was noted that a few pieces of grass did survive, and turf authorities worked with those and with plant breeders to try to develop resistant selections.

The first major development was a joint introduction from the University of Florida and Texas A&M of a vigorous variety that seemed to be immune to SAD. Named Floratam in honor of the two schools, it was widely anticipated and eventually distributed. Many of us replanted entire lawns with it.

There was one shortcoming. Floratam, while able to withstand SAD, could not withstand winters north of Houston or San Antonio. Thousands of lawns and millions of dollars of Floratam (including mine) were lost the next winter.

The lesson I learned: Don’t recommend any new variety until you’ve watched it for several years under a variety of circumstances.

I’ve put that same caution to use in the ensuing years when allegedly shade-tolerant varieties of fescue, buffalograss, and St. Augustine were being introduced into the market. Sure enough, within a couple of years all the hype had died down when it was discovered that they weren’t any better than what we already had. Additionally, it turned out that bermudagrass invaded and overtook almost all buffalograss sod that was laid in Texas within the first five years of planting.

Somewhere in there 30 or so years ago along came the loropetalums (fringeflowers). They were billed as the next great shade shrub for Texas. However, we found them to be very needy when it came to acidic soils. In the Metroplex they ended up thriving for five or six years before their leaves started turning pale green, then yellow, then brown from iron deficiency.

If you go way back in my career you can find writings where I recommended Bradford and other ornamental pears for their bright white spring flowers, dark green foliage, and astounding fall color. However, like everyone else, we found out about 15 years after they hit the market that they have terrible branch structures. The trees begin to break apart while still very young.

Our Bradford pear split in half when it was only 12 years old. Sprouts from their roots are of the rootstock Callery pear, and they produce flowers that are fertile, leading to invasive seedlings that now have the trees entirely banned in several states. So, if you have any of my old newspaper clippings where I recommended ornamental pears, please just take them out and burn them for me.

I’ve mentioned several times over the years that my dad and uncle were both Ph.D .botanists at Texas A&M. The meaning of “native plants” was drilled into my head from a young age, reinforced every time I asked why we didn’t have East Texas pines or West Texas purple sages growing natively in College Station. “A plant is only ‘native’ where you find it growing on its own in nature. It may not be ‘adapted’ a quarter mile down the road.” I heard that time and again.

That’s why the big push toward using only native plants in North Central Texas landscapes has left me a bit cool over the years. Those Texas sages don’t grow here natively because we get too cold. West Texas cacti don’t grow here natively because our soils are too wet (sometimes). East Texas pines can’t handle the alkalinity, and wax myrtles and bald cypresses struggle with drought.

In 2004 an insect sample was brought to me by a store manager of a local nursery. It was adhering to a twig of a crape myrtle. I didn’t recognize it, so I engaged an entomologist with the Texas AgriLife Extension Service. He was also stumped, so he shared it with colleagues in College Station and at the University of Florida. Ultimately it was decided that crape myrtle bark scale had come in past customs from China. It spread around North Dallas and Collin Counties, peaking in a serious outbreak in the rainy spring and early summer of 2007. Curiously, different climatic years coupled with natural predators that came on the scene have kept populations much more in check in ensuing years. I learned not to panic at first signs of a new problem.

Sadly, watching rose rosette virus (RRV) about that same period of time, I’ve learned that some issues are much more difficult to solve. Research has failed to find a means of preventing or curing the fatal virus to date, and the world’s favorite flower has been put at great risk. Research continues with the world’s greatest plant pathologists and horticulturists and hopefully progress will come before much longer.

One final thing I’ve learned has to do with our Hardiness Zone. If you can find a map from the USDA published in 1990, that’s the one you should follow. Subsequent “updates” from 2012 and 2023 are flawed by winters in the early part of this century. Those years were warm, so the USDA used the averages to tell us that we had been moved to Zone 8. That implied that our winters had warmed by 10 degrees on average. There have been several winters since 2012 that showed that to be inaccurate, most notably February 2021. Buy plants labeled for Zone 7 and warmer (Zones 6 and 5) for the best results. Limit your numbers of Zone 8 plants.