From witchipedia.com http://www.witchipedia.com/heather#toc4
Heather is feminine in nature and ruled by Venus and the element of water. It is also associated with Gemini and, accordingly, Mercury. It is represented by the Ogham letter Ura. It is associated with the God Nechtan Mac Labraid, the Cupbearer of the Tuatha De Dannan, guardian of the sacred well of Segais and husband of Boane, after whom the river Boyne in Ireland is named. Also, Isis, Osiris, Venus, Aphrodite.
Heather can be used in spells relating to new beginnings, and self-discovery, enhancing physical beauty and bringing a peaceful resolution to any conflict. It is also used at initiations.
Keeping heather about the house will attract friendly spirits and will bring peace to the household. Carrying heather will attract positive energies, general good luck and protect against rape and other violent assaults, making it useful for traveling sachets.
Burning heather together with fern will aid in magic designed to bring rain. The two plants can also be bundled together and used to sprinkle water on the ground for the same purpose.
Heather helps in summoning spirits and attracts faeries to the garden.
Heather is a good plant to use to make besoms and can be added to midsummer fires to ensure the fertility of the attendants.
Heather is said to be stained with the blood of war in Scotland, thus, white heather is the luckiest and the best for use in magic.
Heather should be part of a bridal bouquet or the decorations to ensure good luck to the couple and peace and cooperation in their household.