University of Vermont Extension 
Department of Plant and Soil Science

Anytime News Article

Dr. Leonard Perry, Extension Professor
University of Vermont
The false indigo (Baptisia australis) has been named as the perennial plant of the year for 2010 by the Perennial Plant Association.  This professional organization for growers and landscapers polls its members nationwide each year on a perennial the majority feel is worthy of wider use and recognition.  The false indigo is an excellent choice for perennial of the year as it is quite hardy (USDA zones 3 to 9), has multiseason interest, is tough, and is low maintenance.

The false indigo is called this from its past use as a substitute for indigo dye.  The genus name comes from the Greek "bapto" meaning to dip.  Leaves resemble those of clover. The indigo-blue pea-like flowers on stalks arise above the gray-green leaves of this species in June in the north, followed late in the season by attractive blackish seedpods that rattle in the wind. 
This perennial is often called an "instant shrub" as it emerges from the ground in spring to form a rounded shrub-like habit by early summer, about 3 to 4 feet tall and to 6 feet wide.  It increases in size slowly, forming a large clump over several years.  As it may be difficult to transplant due to its deep roots, place where you'd like it to remain and allow it plenty of space.  Plants may seldom, if ever, need dividing given good soil and space.
The false indigo prefers full sun for best habit and flowering.  It will tolerate part shade, but will be leggy (may need staking) and with less flowers.  Other than a well-drained soil, it will tolerate most.  Once established it will even tolerate poor, sandy, and drought conditions. Other than perhaps voles (field mice) damage when young, this perennial has no significant problems. 
Don't cut back until late winter or spring in order to enjoy the habit and attractive seed pods.  Seeds seldom self-sow.  Although it takes several years, the species can be grown from seeds sown fresh.  Otherwise, as with many in the pea family, you'll need to soak seeds overnight or abrade the surface with sand paper to let water enter.
Use the false indigo as an herbaceous shrub in borders towards the center or back in small groupings, or as a specimen.  Being a native to the eastern U.S. you can use it in native gardens, prairie gardens, and cottage gardens.  It combines well with bluestars (Amsonia), Carolina lupine (Thermopsis), the silver artemisias, perennial geraniums and ornamental grasses.
In addition to this species, there are several selections and hybrids that have been introduced recently with white and yellow flowers, some even two-tone.   All are attractive and durable.  One of the first cultivars (cultivated varieties) of these was 'Purple Smoke' with dark stems and purple flowers.  'Carolina Moonlight' has soft yellow flowers, while 'Screaming Yellow' has bright yellow ones.  A less common introduction you may have to find online is the white 'Wayne's World'. 
Several introductions have come recently from the Chicago Botanic Garden.  'Solar Flare Prairieblues' has flowers that start bright yellow and turn deep orange with age.  The result, as new flowers emerge, is all colors at the same time.  'Starlite Prairieblues' has soft blue flowers that are white at the base or "keel" of the petals.  'Twilite Prairieblues' was their first introduction and has violet-purple flowers, almost burgundy in some locales, which have yellow keels.  'Midnight Prairieblues' is attractive for both its violet-blue flowers and long bloom period.

Return to Perry's Perennial Pages, Articles uvmext logo