Yellow Leaves on My Brugmansia

Brugmansia, also known as angel's trumpets, is a genus of subtropical flowering plants with showy flowers. Aphids and southern red mites both cause yellowing foliage on brugmansia. Early identification and control are critical for preventing damage.

Types

Aphids are small insects that suck nutrients from brugmansia leaves and stems. Aphid populations are highest during the spring and fall, reports the University of Rhode Island Landscape Horticulture Program. The southern red spider mite is a small arachnid that sucks nutrients from leaf tissue. Spider mites feed on the underside of brugmansia leaves along the veins.

Identification

Aphids range in color from green to black and cause leaf curl, leaf yellowing and stunted leaf growth. Aphids secrete a substance known as honeydew when they feed, which causes sooty mold fungal growth, according to the University of Connecticut Extension. Symptoms of a spider mite infestation consist of foliage yellowing, bronzing and flecking. The University of Florida IFAS Extension recommends using a magnifying lens to identify the .02-inch mites on foliage.

Control

Small aphid populations rarely do enough damage to warrant control. However, insecticidal control is effective for severe infestations. The University of Florida IFAS Extension recommends using horticulture oil every seven to 10 days to control spider mite populations.

References

• University of Rhode Island Landscape Horticulture Program; Aphids; 1999
• University of Connecticut Integrated Pest Management; Greenhouse Update; Leanne Pundt; March 22, 2010
• University of Florida IFAS Extension; Southern Red Mites