Though Plantain was considered by the ancient Saxons to be one of the nine sacred herbs, this appears to be more due to the medicinal qualities of the plant than its magickal energies.  In Magickal lore, it is bound to Mars and Fire.

Today, Plantain is brewed as a tea for divination and vivid dreams, and it is considered a protection herb when placed in a charm around the neck of a child. For healing and purification, place fresh or dried Plantain leaves or roots in a mesh bag hung under the faucet for bathwater.  Pinches of dried herb can be tossed into a fireplace or over the flame of a candle, or thrown into an easterly wind for healing wishes. 

Burning Plantain leaves or roots enhances the magickal powers of other herbs.