Ruellia

A genus of perennials, that are often referred to as "petunias" though are usually much more permanent, bushier and with colors in shades of blue.

Ruellia brittoniana ( Mexican Petunia )
A fast growing perennial, reaching a maximum size of 6 x 6.5 feet, that is native from southern Mexico to northern Argentina. It is now also running wild in the U.S. in parts of Texas, the Gulf Coast and in Florida.
The linear leaves, up to 12 x 0.8 inches, are luxuriant mid-green.
The violet-blue, petunia-like flowers, up to 3 inches long, are borne late spring through early autumn.
The flowers attract butterflies and hummingbirds.
Hardy zones 7 to 11 in full sun to partial shade on just about any soil, wet or dry, sand or clay. It performs very well in the deep south and on moist, fertile soil may become invasive. It is deer resistant. Propagation is from seed, cuttings or division after the first autumn frost.

* photos taken on May 28 2017 in Ellicott City, MD

* photos taken on May 28 2018 in Elkridge, MD

* videos found on Youtube




'Chi Chi'
Vigorous but compact in habit, reaching up to 3 x 3 feet.

Ruellia carolinensis ( Carolina Wild Petunia )
A perennial, reaching up to 3 ( rarely over 1.5 ) feet in height, that is native to open woodlands in the southeastern U.S. ( from southern Illinois to New Jersey; south to central Texas to south Florida ).
The ovate or oblong leaves, up to 4.8 inches in length, are glossy mid-green.
The lavender-blue flowers, up to 2 inches in length, are borne late spring to late summer.
Hardy zones 6 to 9 in full sun to partial shade shade on either moist or dry, well drained soil.

* USDA-NRCS PLANTS Database

* historic archive photo

Ruellia humilis ( Wild Petunia )
A shrubby perennial, reaching a maximum size of 4 x 3 feet, that is native to dry woodlands in the midwest U.S. ( from central Nebraska to Michigan to central Pennsylvania to Maryland; south to central Texas to far northern Georgia ). It is not found on the Atlantic Coastal Plain and is endangered in Minnesota, Wisconsin, Michigan, Pennsylvania, West Virginia, Maryland, Virginia, North Carolina, South Carolina and Georgia.
The oval or oblong leaves are up to 4 x 1 inches in size, are mid-green.
The lavender-blue flowers, up to 3 x 2 inches in size, are borne all summer long. The flowers resemble petunias.
Hardy zones 4 to 9 in full sun to partial shade. Tolerant of reflected heat and dry shade.

* photo taken by Clarence A. Rechenthin @ USDA-NRCS PLANTS Database

* photo taken @ U.S. Botanical Garden, Wash., DC on Aug 25 2014

'Blue Shade'
Reaches a maximum height of only 10 inches but is wide spreading in habit, rooting by creeping stems.

Ruellia peninsularis ( Desert Ruellia )
A fast growing, dense, evergreen shrub, reaching up to 5 x 6 feet, that is native to Baja California.
The small leaves, up to 1 inch long, are glossy bright green.
The purple, trumpet-shaped flowers, up to 2 x 1.5 inches in size, are borne spring into early summer, sporadically the remainder of the year.
The stems are bright gray.
Hardy zones 9 to 11 in full sun on well drained soil. In zone 9 freeze damaged wood will need to be pruned out during early spring.