Yellow leaves, green veins (new growth)
Iron chlorosis from our alkaline clay. Azaleas, gardenias, roses, hollies, pin oaks. Fix: chelated iron spray plus soil sulfur; long term, pine-bark mulch or a different plant. See the soil guide.
Yellow lower leaves, wilting in wet soil
Overwatering / poor drainage. The number one killer of new plants here. Fix: stop watering until the top inch is dry, pull mulch back from the stem, improve drainage with expanded shale next time.
Dusty, stippled, faded leaves; fine webbing
Spider mites — worst in hot dry weather on tomatoes, junipers, marigolds, roses. Fix: blast leaf undersides with water every 2–3 days; insecticidal soap or horticultural oil in the cool of the morning.
Sticky leaves, black sooty film, ants
Aphids, scale or whiteflies — the stickiness is honeydew and the black is mold growing on it. Fix: a hard spray of water, then insecticidal soap; horticultural oil for scale in winter; systemic for crape myrtle bark scale.
White powder on leaves
Powdery mildew on crape myrtles, roses, zinnias, squash. Fix: more sun and air, water at the base not the leaves, a fungicide or neem oil at first sign; choose mildew-resistant varieties next time.
Circular brown patches in the lawn (fall)
Brown patch in St. Augustine and Zoysia when nights cool. Fix: water only early morning and less often, lawn fungicide at first sign, no nitrogen after October 1. See the lawn calendar.
Dry-looking lawn patches by concrete (summer)
Chinch bugs in St. Augustine — they suck the sap and the grass looks drought-stricken but does not respond to water. Fix: confirm by parting the grass at the edge of the patch; treat with a lawn insecticide labeled for chinch bugs.
Turf peels up like carpet (July–August)
Grubs. Fix: a curative grub product now, a preventative next April–May. Birds and armadillos tearing up the lawn are a tip-off.
Holes chewed in leaves overnight
Caterpillars, snails or slugs. Caterpillars (including tomato hornworms): Bt spray, which only affects caterpillars — but that includes butterfly caterpillars like monarchs and swallowtails, so spray only the plants being eaten and keep it off milkweed, fennel, parsley and other butterfly plants. Snails and slugs after rain: iron-phosphate bait, and pull mulch back from tender plants.
Brown scorched leaf edges in summer
Usually heat and water stress, not disease — especially on Japanese maples, hydrangeas and anything planted this year. Fix: deep watering at the root ball, afternoon shade if possible, mulch. Do not fertilize a stressed plant.
Written by the Nursery Professionals at Landscape Source Nursery, 167 Ole West Lane, Rockwall. Questions? Call (469) 698-0037 or send us a note.