Your bardic music can affect plant creatures.
Prerequisites: Perform 10 ranks, bardic music.
Benefit: You can alter any of your mind-affecting bardic music abilities (or similar Perform-based abilities from other classes) so that they influence only plant creatures instead of other creatures. However, plants receive a +5 bonus on Will saves against any of these effects.
Normal: Plants are normally immune to all mind-affecting spells and abilities.
Source: Complete Adventurer, page 110.