Century Plant (Agave) Die-Off After Landscaping: Weevils or Plastic Liner?

Rock Garden Agaves: 3-4 Large Plants Tipped Over and Died Post-Cleanup

Austin, TX garden: 20+ agaves, mother bloomed 4 yrs ago. Landscaper cleaned rocks, replaced plastic liner, trimmed dead lower leaves, moved pups. Since then, several large agaves died. Landscaper found root-eating "worms" (borers) in removed dead plants.

Two Main Theories

1. Agave snout-nosed weevil—larvae bore into crown. Link to treatment page provided.
2. Plastic liner trapping moisture—causes rot. "Weed cloth" (permeable) is better than plastic.

Physical disturbance during cleanup may have damaged roots of old plants. New/medium plants unaffected.