Enormous, zebra-striped leaves of psychedelic purple, green, purple, red and orange can simply belong to croton “Petra” (Codiaeum variegatum var. pictum “Petra”). As flashy as any shrubs grown for their foliage, “Petras” are perennial in U.S. Department of Agriculture plant hardiness zones 9 through 11. Elsewhere, they bring bursts of the tropics inside. Wherever you grow them, expect “Petras” to attract a threesome of annoying insects. Isolate infested indoor plants instantly, and shield yourself from the plant’s skin-irritating sap using gloves, a long-sleeved shirt and long trousers when you handle the insects.
Messy Mealybugs and Sloppy Scales
Mealybugs and scale insects protect themselves beneath layers of wax. They drain sap from croton leaves with sharp, strawlike mouth components, excreting sugary, sticky waste as they feed. Mealybugs resemble little whitish fluff along the stems and leaf veins. Barnaclelike scale insects pass for organic leaf and stem growths. Healthy crotons tolerate mild feeding without severe harm, but too many insects can weaken the plants.
Swab, Scrape and Spray
Eliminate little mealybug colonies by dabbing the individual insects using cotton swabs dipped in rubbing alcohol, or even washing them off with a strong spray of water. Scrape scales off using a toothbrush. Spray severe infestations of either pest using ready-to-use insecticidal soap before all the plants’ surfaces drip. Safe for indoor and outdoor use, the soap doesn’t damage the parasitic wasps and ladybugs that prey on the insects after it dries. Spray on a muddy day to protect outdoor crotons from sunlight damage. Apply the soap every two to three days, or as frequently as the label suggests, until the bugs are eliminated. As a precaution, wear safety goggles and a respiratory mask while spraying.
Web-Spinning Spider Mites
Nearly invisible spider mites spin fine webs on the backs of “Petra'” leaves. Their feeding bronzes or stipples the leaves as a severe infestation can cause the leaves to turn yellow and fall off the plant. . Mites are common on dry, dusty crotons, therefore hose down your outdoor plants two or three times weekly during prolonged dry spells, and mist your indoor plants regularly all year. To remove spider mite colonies, wipe each leaf separately using a soft cloth moistened in warm, soapy water. For a speedier solution, use insecticidal soap as you would for mealybugs and scales.
Slender, pale yellowish to black thrips hatch from eggs inside a croton’s leaf cells. The plants might develop a silvery or brownish wax, or even be freckled using the insects’ black waste. To control thrips outside, hose your “Petras” down with cold water in the morning while the insects are lethargic. For the best results, spray for 2 consecutive days. To treat mild indoor infestations, prune and dispose of the affected leaves in sealed bags. Eliminating persistent thrips may call for insecticidal soap applications every three days for 2 weeks. Like spider mites, thrips attack dry, dusty plants Discourage future strikes with frequent watering and misting.