Common Name: rose vervain
Type: Herbaceous perennial
Family: Verbenaceae
Zone: 5 to 8
Height: 0.50 to 0.75 feet
Spread: 1.00 to 2.00 feet
Bloom Time: May to September
Bloom Description: Lavender pink
Sun: Full sun
Water: Dry to medium
Maintenance: Low
Suggested Use: Annual, Ground Cover, Naturalize
Flower: Showy
Attracts: Butterflies
Tolerate: Drought, Dry Soil, Shallow-Rocky Soil
Culture
'Shauna Ann' is considered to have the best winter hardiness of any of the glandularias currently being sold in commerce (U.S. patent documents claim winter hardiness to USDA 4).
Noteworthy Characteristics
Glandularia canadensis is commonly called rose verbena, clump verbena or rose vervain. It is a Missouri native perennial that typically occurs in prairies, fields, pastures, rocky glades, roadsides and waste areas in the central and southern parts of the State (Steyermark). It is a clumping, sprawling plant that grows to 6-18” tall, and can spread rather quickly by pubescent, decumbent stems, rooting at the nodes where they touch the ground, to form an attractive ground cover. Flat-topped clusters of 5-petaled, rose-pink to rose-purple flowers appear atop ascending stems in a long, late spring to late summer bloom. Deeply lobed dark green leaves (to 4" long) have triangular bases.
For many years, Glandularia canadensis was known as Verbena canadensis. Many prestigious authorities (e.g., The Royal Horticultural Society) still list the plant as Verbena canadensis. The revised edition of Steyermark's Flora of Missouri (Yatskievych and Turner) now lists the plant as Glandularia canadensis. Glandularia is considered by many authorities to be a genus that is separate and distinct from Verbena based upon a number of factors including plant morphology, chromosome number, style length, reproductive modes and ploidal levels (see Umber, The Genus Glandularia (Verbenaceae) in North America, 1979).
Genus name from Latin means acorn in probably reference to the shape of the seedpod.
Specific epithet means of Canada.
‘Shauna Ann’ is a compact cultivar that typically grows 6-10” tall. It was discovered growing in a garden in Laurel, Iowa in 1987. Parents of this patented plant are unknown, but U.S. patent documents suggest it may be an interspecific hybrid, with Glandularia canadensis a likely parent. 'Shauna Ann' features flat-topped clusters of 5-petaled, bright lavender-pink flowers atop ascending stems in a long late spring to fall bloom. Deeply lobed, dark green leaves (to 4” long) have triangular bases. U.S. Plant Patent PP11,926 was issued on June 12, 2001.
Problems
No serious insect or disease problems. Some susceptibility to powdery mildew. Botrytis blight and root rot may occur in wet soils. Snails and slugs may attack the foliage. Watch for spider mites, particularly in dry conditions.
Uses
Mass in rock gardens or border fronts. Spreads to form an attractive ground cover with a long and floriferous summer bloom. Edging. Containers. Hanging baskets.