Saturday, June 18, 2011
Four-petal St. John's-wort - Hypericum tetrapetalum
Four-petal St. John's-wort (Hypericum tetrapetalum) occurs statewide in Florida; primarily in moist soil habitats, but also in upland ecotones where soils are occasionally more droughtly. This is a near endemic and found outside of Florida only in parts of southern Georgia.
Four-petal St. John's-wort is an evergreen woody shrub that may reach a mature height of about 3 feet. It is an openly branched species with thin stems and oval blue-green leaves that clasp the branches. It assumes an irregular aspect with the leaves most confined to the branch tips.
As its common and Latin names suggest, four-petal St. John's-wort produces flowers with four canary-yellow petals. They are showy and about 1/2 inch wide. Flowering can occur in most months, but is most common in late spring. Well-grown specimens may have a dozen or more blooms at any one time.
Four-petal St. John's-wort is one of the better members of this genus for the home landscape. Although it is naturally found in wet to moist locations, it adapts well to most typical home landscape conditions, except excessively droughty soils. In our Pinellas County landscape it has done well in a variety of settings, but seems to prefer partial shade when planted in soils that often dry out. It has spread in parts of our landscape by seed, but never aggressively.
This species is only occasionally offered for sale by nurseries affiliated with FANN, the Florida Assocation of Native Nurseries. If you locate a source, use this plant in mixed plantings in the back half of the bed and cluster 3-5 plants together. Once it is established, it should be an easy plant to maintain.