Gardening This Weekend: May 15, 2025

We have new assignments on our close-in horizon. That’s partly due to the temperatures and partly because of the time of year. Scan through the list.

PLANT
• Watch nurseries for late-spring perennials. Supplies dwindle quickly, so if you see something you like, better grab it and plant it. Watch for coneflowers, cannas, mallows, daylilies, and others. Also fall-blooming perennials such as fall asters and Mexican bush sage.
• Warm air temperatures and soils mean it’s time to plant vincas, copper plants, moss rose and hybrid purslane, fanflowers, angelonias, pentas, purple fountaingrass, and other summer color.
• Watch nurseries for late-spring perennials like coneflowers, summer phlox, cannas, mallows, daylilies, and others. Also fall-blooming perennials such as fall asters and Mexican bush sage. Buy them when you see them. Supplies often go quickly.
• Soils are warm now. It’s the perfect time to start new lawns from seed, sod or plugs. If you wait much longer the intense summer heat will make the job more challenging.

PRUNE
• Continue mowing lawn at recommended height for type of grass that you’re growing. Allowing grass to grow tall does not make it more resistant to hot weather. Tall grass becomes weak grass with a thinner cover that is more subject to invasion by weeds.
• Winter-killed branches from crape myrtles, figs, and other tender plants. Species will vary depending on where you are in Texas, but that reshaping should be done now.
• All spring-flowering shrubs and vines to remove erratic shoots and to reshape for the rest of the growing season.
• Low-hanging branches from shade trees if they are hazards to pedestrians or traffic, or if they’re keeping sunlight from reaching your lawn. Plant pathologists suggest that home gardeners wait until mid-July to prune oaks, although certified arborists know how to protect trees from oak wilt during the pruning and may suggest doing the trimming now.
• Pinch out growing tips of Mexican bush sage, copper plants, fall asters, and new shoots on blackberries to keep plants shorter and more compact.

FERTILIZE
• Turf, trees, and shrubs with all-nitrogen fertilizer with 30 to 40 percent of that nitrogen in slow-release, coated or encapsulated form. Independent nurseries have it and can explain it to you.
• Flower and vegetable gardens every 3 weeks with water-soluble, high-nitrogen food to keep plants growing vigorously.
• Container plants with water-soluble, high-nitrogen fertilizer with every watering. Potted plants dry out quickly and must be watered frequently. Use siphoning proportioner and water breaker or water bubbler as you water.

ON THE LOOKOUT
• Crape myrtle bark scale resembles cigarette ashes stuck to the backs of leaves and the stems and twigs of the trees. They suck sap out of the plant tissues, then exude sticky honeydew residue. The fungus called sooty mold leaves a black growth across the honeydew. To eliminate the sooty mold, you must eliminate the honeydew, and to eliminate the honeydew, you must kill the scale insects. The best way according to university research is to apply the systemic insecticide Imidacloprid as a drench around the plants’ drip lines in the middle of May (now). One treatment, properly applied, should be sufficient. It will also give good control of crape myrtle aphids. They, too, give off massive amounts of honeydew.
• Insect galls on trees. Whether they’re tan, tennis-ball-sized galls on red oaks, warty pecan phylloxera galls on pecan leaves, or nipple galls on hackberry leaves (or any of many other leaf and twig galls), they do little or no harm and there’s no way to control them. Just move on with life.
• Nutsedge. You may know it as “nutgrass,” but it’s not a true grass. Its stems are triangular like all the sedges. All stems of true grasses are round. Treat with Sedgehammer or the original Image according to label directions.
• Mushrooms in lawns are saprophytic, meaning they live off decaying organic matter (tree leaves and roots, grass clippings, etc.). They gain no sustenance from living plant tissues, so they are no cause for concern. Just admire them and move on.