Plant of the week, Purple Rattlesnake Root

Known from only several locations in Kentucky, this outstanding plant provides color in late September and October in Kentucky. The name Prenanthese is derived from the Greek "prenes" and "anthe" flower and racemosa is Latin for "having a raceme" or a cluster of flowers each on its own stem along a single central stem. This is a northern species and Kentucky is at the southern edge of its range which covers the southern Canadian Provinces and the states east of Wyoming down to Colorado over to New Jersey and Pennsylvania.  It is a species of calcareous moist prairies, streambanks,  and wet meadows or fens. It grows from 2 - 5' tall but generally reaches about 3' tall and makes an excellent companion plant with southern blazingstar (Liatris squarrulosa) which has similar growing conditions and flowers about the same time.  This is definitely a sun loving member of the Aster family. This is a species you are most likely going to have to propagate from seed and you should purchase the seed in the fall and then give it a long cold moist stratification period of 150 days.  Several nurseries in Minnesota sell seed and one wholesale nursery sells plants www.morningskygreenery.com.

Since this is a calcareous soil loving plant, and since it grows in moist prairies and other wet areas, this should be a great plant for our limestone soils in Kentucky.  I doubt it likes heavy clay soils, few plants do, but I suspect it can tolerate a good bit of clay although it will thrive in typical average garden soil in a location that gets full sun.  The wonderful thing about this species is that along with the southern blazingstar it provides a source of nectar late into the season.  Because it is a slender plant, as is southern blazingstar, you will need to plant this in a large grouping to get a big show of color as the pinkish to white flower heads are on the small side.  However, en masse, this species is quite showy and compliments the lavender flower heads southern blazingstar.