Hypericum perforatum is one of the less-cultivated Hypericums in UK gardens, and is rarely available in garden centres. With golden star-shaped flowers at the tips of upright stems throughout the summer, this hardy perennial makes an excellent addition to wild flower gardens. Commonly known as St. John's Wort, it is best known for its use in complementary medicine, as an anti-depressant. Height: 100cm (39). Spread: 60cm (24).