Gardening This Weekend: August 20, 2026
Mid- to late August is a pivotal time for gardening across Texas. Scroll through my list and see if you don’t agree.
PLANT
• Last call for seeding bermudagrass. It needs time to establish deep roots before soils start to cool. Water the planting 5-8 min. both morning and evening at these high temperatures.
• Last call for planting St. Augustine sod. It, too, must become well rooted before soil turns cool.
• Last call for finding good selections of crape myrtles at local nurseries. Numbers are diminishing as the plants conclude their second and third rounds of blooms.
• Prime time for buying and sowing bluebonnet and other spring wildflower seeds. They need the early fall rains to break their dormancy so they can become well rooted before winter. Plant them into lightly tilled soil – not in turf areas.
• Prime time for planting transplants of Cole crops (broccoli, cauliflower, Brussels sprouts, cabbage). In the Panhandle sow seeds of leafy and root vegetables soon.
PRUNE
• Last call for pruning bush roses back by one-third, always cutting just above buds facing out from the centers of the plants. If you detect the fatal rose rosette virus, dig afflicted plants including all roots immediately and send them to the landfill in black plastic trash bags.
• Last call for pruning autumn sage (Salvia greggii) back by one-third to stimulate fresh growth for fall blooms. Deadhead all other perennials to remove old flower and seed stalks.
• Do light pruning of errant growth of shrubs, vines, and groundcovers, but save major pruning for mid-winter.
• Root prune non-blooming wisterias to “shock” plants into reproductive mode. Use a sharpshooter spade to sever roots in top 8 in. of soil 15 to 18 inches from trunk. Soak soil several days before you try this.
FERTILIZE
• Give summer annuals a boost to promote good fall growth and blooms.
• Patio pots and hanging baskets with high-N, water-soluble food weekly to compensate for nutrients lost in daily irrigation.
• Bermuda turf with all-nitrogen fertilizer with 30 to 40 percent of that N in slow-release form if it’s been more than 2 months since last you fed it.
• Iron-deficient plants with an iron/sulfur combination product. Keep it off masonry and painted surfaces that could be stained.
ON THE LOOKOUT
• Absolutely last call to apply Image to eliminate nutsedge in your turf and landscape areas. Two applications are required and they need to be made 30 days apart. Ideally, they will fall between May 15 and September 15. That means you can’t delay any longer. Buy the Image product specifically labeled for control of nutsedge and make your first application no later than this weekend.
• Aphids causing sticky drippage from leaves of many species of plants. Most general-purpose organic or inorganic insecticides will kill them. The bigger problem will be in getting the spray up to the tops of tall trees. That may not be practical. The aphids will run their course in 5-6 weeks.
• Leaf scorch (browned leaf edges and tips). This is evidence of moisture stress at some point during the summer. If there has been no injury to trunk or roots, your solution is to keep plant uniformly moist at all times.
• Pre-emergent weed control granules need to be applied the first 15 days of September. Locate a source for Dimension or Halts and use the herbicide to prevent germination of rescuegrass and annual ryegrass. You’ll also get much-needed help in preventing germination of annual bluegrass, although some of it will still germinate.