Perennial of the Month-- June 2009

(bap-TEASE-ee-ah  VAIR-i-col-or) (pronunciation at link, turn up volume if too low)

Common name: Twilight Prairieblues™ False Indigo

Family: Fabaceae (Pea)

Height x width: 3-5ft high and 4-5ft wide

Growth rate: slow, upright

Foliage: resembles large clover, pea-like, 3-parted compound, alternate, blue-green 

Flowers: deep violet-purple fading to dusky violet with lemon-yellow keels in clustered spikes to two feet or more long; midJune north, mid May south for about 3 weeks

Hardiness: USDA zones 4-8

Soil: well-drained to medium wet (not soggy), tolerates poor soils and drought once established

Light: full sun

Pests and problems: none significant

Landscape habit, uses: specimen, massed, borders, prairie and meadow gardens, naturalized borders, shrub hedge; underplant with daffodils and hardy geraniums, and interplant with ornamental grasses such as moor grass, feather reed grass, or switchgrass; interplant with New England asters, tall garden phlox, and false lupine (Thermopsis)

Other interest: an introduction of the Chicago Botanical Gardens (Dr. Jim Ault) through the Chicagoland Grows program, one of several in this Prairieblues series, from a cross of two species (australis x sphaerocarpa); flowers resemble lupines; deer resistant; long lived and easy to grow as most others in genus

Other culture: with taproot hard to transplant once established; may take 3 years to reach mature size and become established; may need staking if too fertile, or if too shady

Propagation: division, stem and root cuttings; plants from seeds will not come true to type

Sources:  patented (PPAF), from licensed propagators commercially, many specialty perennial nurseries