HOW WILDFLOWERS HELP HOUSTON
What wildflowers do for our cities
Our cities, built of lumber, steel, concrete, asphalt and stone, are like most constructed things: They are best right after they are completed, and then they slowly start falling apart. The urban living landscape (made up of parks, creeks and greenspaces) is usually built, as well, but these systems can be designed to regenerate — to grow, resprout, reseed, climb, spread, multiply and get better over time.
But not all living landscapes are created equal. In urban settings, we often use domesticated nonnative vegetation: plants from Europe that can be clipped perfectly into hedges, grass from Africa that can handle major foot traffic and flowers from Asia that stay showy all summer. Most any plant is better than no plants at all, but we can do better by bringing back some native wild species.
Texas is plant rich (“green gold,” anyone?): Our diverse regional landscapes range from the moist piney woods of the east (hello, Houston!) to dry, arid deserts in the west (howdy, Big Bend!), with 12 ecoregions spanning the state.
These ecoregions — geographically distinct
areas with similar geology, climate and biological traits — play host to more than 4,500 vascular plant species. Among these plants are wildflowers, for which Texas is known and of which we are justifiably proud; they have earned many admirers and highprofile champions over the years.
Sure, they inspire romantic plein air paintings and make for sexy roadside photographs, but they do so much more.
Let’s jump right in and get down and dirty with the roots. The depths of wildflower roots vary per species. Annual wildflowers (in and out in just one season, like sweaters in Texas) have shallow root systems, where perennial wildflowers have long and extensive root systems.
The iconic annual Texas bluebonnet has roots that are only a few feet deep (though they do an important magic trick by fixing nitrogen in the soil). In comparison, the perennial Texas blazing star, also known as gayfeather, can have roots as deep as 15 feet. These root systems improve soil health and prevent erosion by holding soils together, slowly filtering water into the ground.
Above ground, the stems, leaves and beautiful flowers of native plants do even more. When planted densely with grasses in an urban setting, wildflowers can slow stormwater, capture airborne particulate matter and cool the surrounding microclimate. I’ve tested this with a handheld temperature detector and have found, on average, that planted areas are 10 to 15 degrees cooler than asphalt.
And now to the main attraction, those blooms. By being colorful and fabulous, flowers have tricked humans into planting them and caring for them. All the while they’re really courting the butterflies, bees and other more helpful species. Basically, plants and pollinators are mutually beneficial. Antelope horns provide nectar for many different pollinators including the monarch butterfly, which also uses the milkweed as a host plant for laying its eggs. Native wildflowers in cities can help sustain native pollinators. Beauty begets beauty.
So, yeah, flowers rule. But don’t be deceived by those vast oceans of bluebonnets along Hill Country roads. Monotypic wildflower shows aren’t ideal (in fact, they’re often an indicator of poor soil quality and overgrazing). What you really want to see is a mixture of annual and perennial wildflowers in a matrix of grasses or other robust ground cover: a living system that increases the variety of flora and fauna and is resilient to climatic changes and storms. You want beauty and biodiversity.
Though a wildflower is defined as “a flower of an uncultivated variety or a flower growing freely without human intervention,” we say go ahead and intervene! We will continue to develop built environments, and we’ll continue to live in dense urban places. But let’s make a little space for living landscapes and invite the wild back in.
Maybe humans will never fully regain Mother Nature’s trust, but we can at least say, “We’re sorry! We’ll do better! Don’t leave us!” with lots and lots of flowers.
Yes, wildflowers can and do occur naturally, spontaneously (wildly, even) on their own. But in our cities, we’ve taken that ability away by blocking and covering so much ground. Our only choice now is to take it back, make some space and plant seeds for a less gloomy, more bloomy tomorrow.