Texas sabal palm troubles & Virginia buttonweed control

Summer’s heat and dry conditions continue to trouble our trees. Vincent Campos has a Texas sabal palm with yellowing fronds. He waters with drip irrigation and uses a slow-release palm food every three months. 

Actually, these trees look really healthy overall to me. The tip-burn on the fronds indicates that the tissue in that area is drying out. This is often caused by heat/drought stress, and can be exacerbated by fertilizers, which are salts. 

To mitigate this issue, I’d recommend adjusting to a deeper irrigation, rather than relying solely on drip, and cutting back on the fertilizer in the summer. Deeper irrigation less often allows water to move deeper into the soil profile than drip may provide, which keeps the plant’s access to water more uniform. 

Speaking of water, a viewer asks: does watering during the day burn plant leaves? Well, that depends on where you’re watering it. If irrigating the soil, as you should, then no, watering during the day would not burn the leaves. But if you are spraying the plants with water, then yes, watering during the day may produce burn spots on the leaves, when the water quickly evaporates and leaves behind potentially caustic mineral salts. 

Houston viewer Amy Cortez recently bought a home that came with invasive Virginia buttonweed. She wants to plant a garden to attract wildlife. What can she do? We reached out to Harris County Extension Horticulturist Skip Richter who agrees that this one’s tough to control, and unfortunately, will require an herbicide to eradicate. 

Here’s what he recommends: 

First, minimize watering. Virginia buttonweed loves wet conditions and overwatering adds to its proliferation. 

Secondly, work to maximize turfgrass density with proper mowing watering and fertilizing.

And lastly, consider hiring a professional to assist with applying an herbicide to selectively treat this weed. Because it has underground stems, it creeps prolifically, so you can’t simply pull it up without leaving some behind to re-sprout. And even one herbicide treatment won’t do the trick on this pernicious weed: multiple applications will be necessary, and mistakes costly, potentially damaging the turf and other nearby plants.

Across Texas, viewers are planting for wildlife! Houston gardener Shelly McDaniel’s got a lot going on, from carpenter bees on her summertime celosia and duranta flowers, to all kinds of butterflies enjoying repeat-blooming coneflowers. And she grabbed another great shot: of a Monarch on milkweed. 

Angela Carver’s garden is just as diverse and beautiful, where perennializing bulb Lycoris radiata sent up spidery flowers a few weeks ago. Her datura ‘Purple Ballerina’ attracts pollinating moths at night, and Pride of Barbados attracts butterflies like this Tiger swallowtail. 

Agnes Fajkus also attracts butterflies to her garden, including swallowtail, and caught a tiny hummingbird taking a quick break. 

In eastern Travis County, DeAnn Smith Caylor documented the birth of mockingbirds from eggs to nestlings. Her husband David is an organic gardener with a degree in agriculture so they nurture gardens and wildlife. 

From Houston, Brennon Romney sent pictures of a giant moth that his young daughter found. They learned that it’s a Black Witch moth, which is so large that it’s often mistaken for a bat. They measured this one at being four to five inches wide.