Agave americana Shriveling at Base: Agave Beetle or Overwatering?

Large 15-Year Agave: Base Leaves Black, Losing Firmness

A 5–6 ft Agave americana in the Southwest desert shows shriveled stalk bases, a few black basal leaves (removed), rest blue-green. Lawn sprinklers run 4–5 min daily; no dedicated emitter for agave. Owner asks if it can be saved.

Two Likely Culprits

1. Agave snout-nosed weevil larvae—eat the root crown, causing rot and collapse. This year is especially bad. Treatment (borer pesticide around base) needed months ago.
2. Overwatering from lawn sprinklers—Agaves need deep, infrequent water. Cut to once every 2+ weeks; watch for improvement.

Diagnosis Tip

Tug the center leaves. If the whole plant moves, the root crown is gone (weevil). If firm, reduce water and monitor.