Monday, September 14, 2009

Hypericum Lifts The Spirits

Hypericum calycinum - St John's Wort - Aaron's Beard
Hypericum (pronounced hi-PER-ee-kum), also known as St. John's Wort or Aaron's Beard, is a genus of herbaceous annuals and perennials of about 400 species.  With so many species, it should not surprise that they are distributed almost world-wide.  Fewer than 100 species are much cultivated.  Less than two dozen of those are commercially available.  I will focus on one, Hypericum calycinum, which is native to Turkey and parts of eastern Europe.

The name, Hypericum, refers to its being hung above pictures or "icons" to repel evil.  The species name, calycinum (pronounced ka-LEE-kin-um), refers to the prominent calyx at the base of the flower.  The common name, St. John's Wort, refers to St. John The Baptist, whose Birthday Feast in June roughly coincides with the beginning of Hypericum's bloom time.  It's possible that there is also some connection to his imprisonment.  The name, Aaron's Beard, refers to the very prominent, hairy-looking stamens of the flower.

Since antiquity, Hypericum has been used for medicinal purposes.  H. perforatum is most potent.  Taken internally, it's supposed to treat depression.  Used externally, the aromatic oil is said to possess antibiotic properties and to aid in healing wounds, burns and concussions.   Having grown up in a family of herbalists, I remember the plant being often pointed out to us.  It is important to note, however, that self-treatment is not advised.  St. John's Wort may interact badly with other drugs and cause hypersensitivity to light.

Oval-shaped foliage covers shrubby stems up to 18" high.  An abundance of butter-yellow flowers continue for several weeks during the summer.  Foliage color is medium to light green during growing season blushed with burgundy in fall.  In warmer areas of its range, leaves are evergreen.  In colder regions, they turn brown but persist through winter.

The plant covers ground very well, so is excellent for erosion control in medium to large areas.  It is also very useful in perennial gardens and borders.  Hypericum is truly a ground cover plant for all seasons.  It's deer resistant, too.

St. John's Wort is hardy in USDA climate zones 5 through 9, though it produces fewer blooms in zone 9.  It thrives in full sun to partial shade in average, slightly-moist, well-drained soil, but tolerates dry conditions quite well.  Recommended pH ranges from slightly acid to slightly alkaline.  Maintenance needs are few.  Trimming it to 6" height in early spring will stimulate lush re-growth.

Before planting, take a soil sample to your local Cooperative Extension Service office.  For a small fee, they can run a lab test and tell you what your soil may need.

Prepare the planting bed by cultivating at least 8" deep, removing all traces of weeds. Compacted soil should be cultivated to 12" deep.   If your site is not well-drained, add enough soil to raise the bed about 4" above the surrounding ground level.  Fertilizer may be used. If you choose to do so, incorporate 10-10-10 fertilizer at a rate of no more 2 lbs. per 100 square feet into the top 4" to 6" of soil. Avoid synthetic fertilizers contacting any part of your plants.

Plant St. John's Wort 12" to 15" apart, or farther. Dig planting holes into the cultivated soil a little less deep than the depth of the growing container.  Water the plants in their pots.  Place the plants into the holes and back-fill, watering as you go. Press soil around the roots, but do not cover the top of the root mass which should remain slightly exposed.

Add a top-dressing of mulch around the plants, not on top of them, about 2" deep.  The mulch helps retain soil moisture, so you can water less frequently.  It also helps suppress weeds.

Irrigate when necessary until the planting is established, but allow the soil to dry between watering.  Keep the bed weed-free until the ground cover begins to suppress weed growth on its own.

Though St. John's Wort has been used as an anti-depressant, it lifts my spirits just to see it in bloom.   Given its historical interest, beautiful showy flowers, and easy cultivation, I believe it will please you, too.

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