The common myrtle (M. communis) is native to the Mediterranean region and the Middle East and is cultivated in southern England and the warmer regions of North America. In Greco-Roman antiquity, the common myrtle was considered to be sacred to Venus and was used as an emblem of love in wreaths and other decorations.
If you have crape myrtles, you have two basic options. One is to allow them to grow into "trees." This can be done, and I've seen them as high as a one-story house. However, most folks will trim them each year so that they remain 4 to 6 feet high. The trick is to trim the plant near the end of winter, around February, so that it doesn't become too leggy. The blooms usually show up around the middle of the summer. Blooms can be white or purple, but are most often a reddish pink.
These are very hardy little buggers; they will live without water for extended periods of time.