Susan is also blogging at GardenRant.Hypericum / St. John’s Wort
This is a group of 400+ annuals, perennials and shrubs, native to North America, Europe or Asia. Famously, it's used as an herbal remedy for depression, particularly H. perforatum.
Natives
- H. buckleyi or Blue Ridge St. John's wort is 6" tall. Native to the Appalachians, it's quite tolerant of heat and humidity. Good in rock gardens. Zones 5-8
- H. ellipticum or Pale St. John's wort is native to the Northeastern U.S. and Southeastern Canada. Forms 2-3' wide clumps. Zones 4-7 or 8.
- H. suffruticosum or Trailing St. John's wort is native to the Southeastern pinelines, so it's very good in sandy soils. Zones 7-9.
Nonnatives
- H. perforatum is consider the "common St. John's wort" and is also the primary plant used for depression treatment. A European wildflower now naturalized in North America. Graham Ricie calls it "a familiar wayside plant that's a colorful addition to the informal or wild garden."
- H. calycinum (photo), another popular St. John's wort, is native to S. Europe and SW Asia. Its bright yellow blooms appear in July and August. Zones 5-9.
Sorry, I couldn't find a photo of a one of the natives.
Details (generalized for the group)
- Full sun to partial shade, but blooming best in sun..
- Moderate spreaders.
- Best in rich soil that's moist, though they're not really picky about soils.
Care (Ditto)
- Most are not particularly drought-tolerant, so definitely need suppelmental water.
- Propagate by dividing in spring or fall, or taking cuttings.
Good Information in Print
- Covering Ground
by Barbara W. Ellis - Encyclopedia of Perennials
by Graham Rice is exhaustive and an outstanding general resource on the subject.
Location Matters
I follow the progress of St. John's wort in my neighbor's garden in the Washington, D.C. area, Zone 7A. If you've grown it and want to comment, just drop me a line. susan
Photo credit: Missouri Botanic Garden. (H. calycinum)