St John's Wort

Hypericum is a widely distributed genus known as St John’s wort, ranging from annuals and herbs to shrubs and trees. Its garden forms vary in stature, foliage persistence, habitat and seasonal display, so mature size and siting should be matched to the identified species or selection. The [RHS genus guide](https://www.rhs.org.uk/plants/hypericum) describes this breadth, and [Kew Plants of the World Online](https://powo.science.kew.org/taxon/30002180-2) accepts Hypericum as a genus in Hypericaceae. ## Character and Uses Many garden Hypericum are grown for bright, usually yellow, five-petaled flowers and decorative berries that may range from cream and yellow to red or black. Shrubby forms can serve as groundcover on slopes, informal hedges or border specimens, while compact alpine forms suit rock gardens. Flowering and fruit display differ among species and selections. ## Growing Conditions Most grow in sun or partial shade and in a range of soils with reasonable drainage. Alpine forms generally need full sun, some species tolerate full shade, and bog-associated plants require wetter conditions. Poor drainage can cause root problems for most Hypericum, while dense shade can reduce flowering and encourage leggy growth. Do not apply a single mature-size range or hardiness rating to the entire genus. ## Maintenance Match watering, spacing and pruning to the identified species or cultivar. Keep most types out of persistently waterlogged soil, while maintaining moist conditions for plants adapted to bog habitats; check local hardiness and mature dimensions for the selected taxon.