Late-season blooms mean stressed plants
The flurry of late-season blooms at Bayou Bend Home & Gardens may look pretty, but it’s really a sign that the plants are stressed and suffering ill effects of Hurricane Harvey.
The Bayou Bend Gardens reopen for winter tours with plants sporting springtime colors — a pretty sight for fall but a sure sign of stress after Hurricane Harvey’s floodwaters inundated the grounds.
Spring-blooming plants that are flowering this fall in the Houston area aren’t happy. Nor are they confused by the warm weather into thinking spring has sprung.
They’re fighting for their lives after Hurricane Harvey’s flooding, says Bart Brechter, the curator of gardens at Bayou Bend Home & Gardens.
“When plants are stressed, they’ll bloom to try to make seed in case they die,” he said. “If you have things blooming out of season, that’s not a good thing. It’s a sure sign of stress, that something’s wrong. The plant is sensing a need to survive.”
Buffalo Bayou rose so high out of its banks during the storm, it reached the trusses of the garden’s entry bridge, covered the elevated statue in the famous Diana Garden and washed over the roof of the cottage that had served for years as a security office.
Filling the basement of Ima Hogg’s former mansion, the flooding also destroyed the property’s mechanical systems. Last week, temporary air-duct tubing still snaked out of ground-floor windows on one side, as
rebuilding continues. But the house museum upstairs has reopened for tours and will have on its winter finery for the annual Christmas Village festivities next month.
Brechter and his staff of seven gardeners have worked six days each week since the storm to make the gardens lovely again in time for the holiday season. Before they could even begin to address the plants, they spent two and a half weeks removing about 200 square yards of silt — about 150 wheelbarrow loads per day — that had piled up in the Diana Garden.
Holiday visitors won’t see any evidence of the trauma: The Diana Garden has a new grass lawn, and the crew has completely rebuilt the crushed granite paths throughout the property that washed away.
And the camellias, at least, are blooming on schedule. They are winter performers.
All of Bayou Bend’s treasured azaleas, camellias, trees and woodland plants have seen floods before, but the grounds usually drain much faster, Brechter said. Harvey’s water didn’t recede for at least four days.
His biggest concern right now is the continued die-back he is seeing on stressed plants — lingering effects that home gardeners in the area are likely seeing as well.
The yew hedge surrounding the statue of Euterpe suddenly went brown about a week ago, and nothing will save it: Any dead bits must be pruned away.
“Larger plants have enough stored energy to maintain them through what just happened, but if they’re not re-growing to restore those starches, they die,” Brechter said. “The flood is still killing things because of the effects it has had.”
Stressed plans are also more susceptible to disease. Rust, a reddishbrown fungus, has attacked some of Bayou Bend’s azalea shrubs. Powdery mildew, which is grayish-white and fuzzy, has shown up on camellia leaves.
Gardeners who see signs of these diseases on home garden plants should remove infected leaves and throw them away; don’t add them to compost. Rust can be treated with a fungicide such as neem oil. Many gardeners treat powdery mildew with a formula that’s easy to make: Mix 1 tablespoon of baking soda and ½ teaspoon of liquid soap into 1 gallon of water; and spray it onto affected leaves. Thinning and pruning to improve air circulation around the affected plants also may help.
But Brechter started with amending the depleted soil because the floodwaters swept away the top layers of organic matter.
“It felt like we needed to start all over,” he said.
He’s snuggling all of the Bayou Bend gardens in a rich blanket for the winter, starting with a base of dried molasses and a mild fertilizer (Microlife 6-2-4), then adding several inches of compost and hardwood mulch. And as leaves fall from the trees, he will let them stay around this winter rather than raking them up for a compost pile.
“We need as much organic matter on the top as we can get,” he said. “All that water neutralized soil and killed mycorrhizals. We add compost to inoculate the ground with more mycorrhizal activity; that generates energy in the soil.”
Brechter cautions against over-fertilizing, though. “You don’t want to do too much because we’re going into the fall. If you fertilize too much, you create another problem because plants may have new, tender growth if we get a freeze,” he explained. “You have to balance what you do for the soil with the time of year we’re in. If this had happened in the spring, we could have fertilized all day. But now, we’re kind of balancing.”
He recommends seeking out a hardwood mulch, such as Nature’s Way brand, that has been aged longer than 90 days. Most composts are aged six months — that’s not quite long enough, he said. “If it’s not aged, it tends to not have as many of the good beneficials, and it’s still a little too hot. It’s the heat you want to get away from.”
Trees may be in trouble, too. They can look healthy for several years after a drought or flood, when they’re actually dying slowly from within.
“You can look for stress if the tree is blooming when it is not supposed to or if the tree has a heavy set of fruit, like acorns or pine cones,” Brechter said.
Like the shrubs, give them some attention now with compost and mulch. And plan to give them another gentle boost in the spring.
Plants, like people, are going to take a while to recover from the beast that was Harvey.