Between hurricane ike in 2008 and the prolonged drought of 2011, the Houston Arboretum & Nature Center saw half of its trees topple and die. To canopy-loving Houstonians, this was nothing short of tragedy. But to the nature specialists at the Arboretum, it represented a fresh start. After all, those trees were never supposed to be there in the first place.
The Arboretum, which was originally carved out of the surrounding Memorial Park in 1951 as a nature sanctuary in the midst of the city, is hard at work constructing the landscapes and trails of a new master plan created in the aftermath of the great tree-mortality event. Call it a blessing in disguise, call it a silver lining—or call it “refiguring our relationship with the landscape,” as Emily Manderson, the Arboretum’s conservation director, does.
After said refiguring took place, Manderson moved to Houston from Austin, where she worked at the Lady Bird Johnson Wildflower Center, and set out to help the local treasure hit the reset button, along with arborists and other experts.
Most of the Bayou City was a prairie, of course, before well-intentioned settlers and developers came along and planted fast-growing, decorative live oaks and other trees where they didn’t belong. Our original landscape was covered with what Manderson calls “pimples and dimples”: subtle, six-inch mounds and dips in the earth that were hard to notice through the up-to-eight-foot-tall thickets of grass that grew here. The “high” spots were mounded up with the type of sandier, loamier soil in which slow-growing, drought-resistant post oaks thrive; the dimples lay atop dense, goopy clay which was unsuitable for trees but perfect for lush, tall grass.
“This is the kind of topography you want to have in a Gulf Coast space—it acts like a sponge,” explains Manderson. “So during a big rain event, you’ve got these native grasses where two-thirds of their biomass is underground, if not more. They’ve got this great system that filters the water through and cleans it, and they can break through the clay. If you don’t have those grasses, you have flat clay. That’s why you have more flooding—because you have these more-impervious surfaces.”
Much of the work of implementing the Arboretum’s master plan involves removing the invasive species that quickly took over following the loss of its pines, live oaks and other trees in 2011, while restoring many of its 155 acres to something approximating the native landscape of Gulf Coast prairie and post oak savanna, reseeded with plants like bushy bluestem grasses, cheerful coneflowers, and graceful liatris, which blooms a gorgeous violet in the late summer.
Yes, this involves removing even more trees in the process. But the restored prairies will have breathing room to grow into functional ecosystems that will support native wildlife, as well as flora that couldn’t survive under a huge tree canopy.
Want proof that these prairies work? The Arboretum took almost no damage during Hurricane Harvey, the scrubby landscape and soil soaking up flood waters like, well, a giant sponge. A few more trees fell, but otherwise work on the new Master Plan continues unabated.
Still, Manderson and her staff know this new landscape could be a disappointment for Houstonians who are accustomed to woodlands greeting them when they enter the Arboretum. “So many people see this as a sanctuary in the city,” Manderson acknowledges, “and they don’t want to lose that sense of quiet.”
But this new Arboretum—which will still have plenty of wooded trails; the southern side, near the bayou, will keep its Piney Woods ecosystem—also presents a unique opportunity for education, says Christine Mansfield, marketing and development manager for the Arboretum. Like Manderson, Mansfield is a native Houstonian who grew up thinking crepe myrtles and tallow trees were as native to our city as mosquitoes.
“People are starting to realize that Houston has a prairie history,” says Mansfield. “I love having these conversations with people. Their eyes just get giant. As awful as it was, the drought-hurricane combo also helped pave the way for that conversation. Those trees were not here, not that long ago.”
In 2018 and beyond, look for a new entrance off Loop 610 and a renovated one on Woodway Drive, with plenty of parking at both, plus two educational wetlands spaces (that double as storm-water retention sites), a state-of-the-art playground, and two new buildings.
In the meantime, the hope is that Houstonians will learn to love their native, albeit unfamiliar, prairie environment—though Mansfield admits it’ll take some getting used to.
“When you first look at them, prairies aren’t exciting compared to that big nature that smacks you in the face,” she says. “Prairies are kind of understated, and it takes some time. But once you start looking and listening, there’s so much more going on in a prairie than in a forest. It just sounds alive, with all of the crickets and dragonflies and everything that’s buzzing. But it does take time to sit there and be with it.”