Lovely Companion Plant for Your Vegetable Garden: Phacelia
Phacelia is a genus of annual and perennial herbaceous plants from the Americas. These quick growing plants are usually used in massive plantation schemes for cover empty spaces and for their attractive spring blooms. These sun loving plants are easy to grow and require moderate watering in a well-drained soil.
One of the commonly known species is Phacelia Campanularia or California Bluebell. It is a fast growing plant with fresh green foliage and blue flowers that appear in spring or summer. Like most species of Phacelia, it attracts bees and hoverflies that kill aphids thus making it a good companion plant in vegetable gardens.

Phacelia, Image by Wayfinder_73 (flickr)
Phacelia Campanularia can be grown as ground cover or border plant near lettuce, tomatoes, roses or other flowering plants or fruit trees that are prone to aphid attack.