Tradescantia (Spiderwort) purple

Tradescantia virginiana 

Or Spiderwort 

• Plant height: 10 to 24 inches
• Bloom season: May – September
• Grow in part shade or sun
• In spring the 3-petaled flowers appear and last for a day but new ones are produced daily in terminal clusters. Flower colors range from blue to purple to pink. Once they have finished blooming cut back the stems. 
• Best leaf color when planted in full sun.
• Deadhead flowers to help lengthen bloom time.
• Cut plants back to a few inches above the ground when leaves start to brown and decline. If this happens earlier in the season, the plant may have a second round of growth.