NPS Photo

Pulling Canada thistle stresses the root system and helps prevent its spread.

Invasive exotic plants such as Canada thistle and leafy spurge, if not controlled, can choke out native vegetation. Aggressively invasive non-native plants are known as "noxious weeds."

Jewel Cave National Monument uses an integrated pest management (IPM) approach to control noxious weeds. IPM includes manual / mechanical control (hand-pulling and cutting), chemical control (application of herbicides), and biocontrol (introducing insects which attack the plant).

Jewel Cave relies primarily on manual / mechanical methods to control exotic plants. Hand-pulling removes part of the root system and stresses the plant. Cutting prevents the plant from producing seed.

To prevent contamination of water inside the cave, herbicide chemicals cannot be used in most areas of the park. Biocontrol agents such as Apthona flea beetles are used to control leafy spurge, and have been quite successful where they have been released.