I picked up my one St. John's Wort 'Brigadoon' at our neighborhood plant swap three years ago. Its chartreuse leaves were a cheery pick-me-up for the dark depressing spot where the photinas prevented any happiness from growing. It put out a few new shoots in year I while continuing to allow soil to wash into my lawn (excuse me - since I am a master gardener, the term is turf.) In year II, a few more shoots and one flower was all it could muster. I began to think the internet lied about an easy-growing perennial. Now year III sees it filling in nicely and maturing to the ground cover and erosion control it was born to be.
Besides its slow growth (good because I already have ample invasive plants to control), it is only about 6-inches high (15 cm). Yellow flowers are not very abundant. The leaves darken with age, but remain light enough to brighten up a shade.
Now the interesting facts. The name comes for is bloom time around June 24 when the birthday of St. John the Baptist is celebrated. It is believed to be native to Europe and Asia, and maybe western US, and has been classified as an invasive noxious weed in some countries, especially where cattle and livestock are raised. Ingestion by livestock can cause photosensitization, central nervous system distress, depression, spontaneous abortion, and can lead to death. How can you tell if a cow is depressed? All cows seem depressed to me. Maybe I am confusing depression with laid-back.
It was used by early Greeks for ailments including nervous disorders. Studies have proven it as effective as Prozac in the treatment of mild to moderate depression, but are inconclusive for severe depression. The major downer for taking St. John's Wort is its dangerous side effects from interactions with other medications and herbs.
For The Record:
Heavy clay soil with gypsum & organic amendments with small amount of fertilizer
Full light shade
No serious pests or disease
Blooming: echinacea, daisy, lily, daylily, nicotiana, cleome, hydrangea, loostrife, hosta, astilbe, lavender
Harvested: radish, beans