What's eating my little bluestem?

Little Bluestem is a tough native prairie grass with modest pest pressure. Rust is the most common complaint, creating orange pustules on the blue-green blades in humid summers. Aphids visit young growth, armyworm caterpillars can cause defoliation in late summer, and grasshoppers chew blades in dry conditions. Deer occasionally browse new growth but rarely cause lasting damage.

Orange to reddish-brown powdery pustules on leaf blades and sheaths; heavy infection causes early browning before the plant's prized autumn copper color can develop. Annual cutback in late winter clears infected tissue; site in full sun with good air flow; sulfur or myclobutanil fungicide for persistent annual infections.

Colonies on fresh spring shoots cause honeydew deposits, minor distortion, and attract sooty mould on the lower blades. Water jet to remove; insecticidal soap for heavy infestations; natural enemies (ladybugs, parasitic wasps) provide effective season-long suppression.

Nocturnal caterpillars chew blades rapidly in late summer, leaving ragged, stripped sections across the clump before the autumn display. Apply Bt or spinosad at first sign of caterpillars; inspect in the evening; outbreaks are most likely in south-central and southeastern US.

Chew irregular strips along blades in hot dry summers, dulling the blue-green color and reducing overall plant vigor. Nolo Bait (Nosema locustae) applied in early season as a biological control; encourage bird activity; chemical options include carbaryl for severe infestations.