Portulaca grandiflora, commonly called portulaca or moss rose, is an evergreen perennial often used as an annual. Portulaca is native to Brazil, Argentina and Uruguay. The genus Portulaca contains other plant species, but P. grandiflora is the main species grown commercially.
Portulaca is a low-growing (up to 12 inches), succulent, evergreen perennial with a trailing, branched habit. Portulaca has simple, alternate, cylindrical leaves up to 1 inch long. Its leaves are light green and smooth with entire margins (without indentation or lobes). Rose-like portulaca flowers include bright shades of red, yellow, orange or white and open up to 1 inch across with various numbers of petals depending on the cultivar.
Use portulaca as a bedding plant, in edging, ground cover or in hanging baskets. Portulaca tolerates hot, dry sites like rock gardens. It is commonly grown as a garden annual, but it is a perennial in warm climates. Portulaca grandiflora is an easy-care annual plant and is a good choice for new gardeners.
Flower color and growth habit vary by cultivar, and many have been developed for specific traits. Aztec Double has double flowers. Dwarf Double Minilacea hybrids are compact with large flowers. Extra double hybrids have a spreading habit and double flowers. Peppermint Candy has single, bi-colored flowers, and the Sundial series is available in nine colors.
Grow portulaca in full sun in various, well-drained soils. Cultivation on wet soils may cause root rot. Portulaca is heat and drought tolerant. Space plants 6 inches apart for optimum flowering. Its flowers only open during sunshine. Portulaca blooms during warm weather. Grow portulaca as an annual in all zones and grow as a perennial in USDA Hardiness Zones 9 through 11.
Portulaca reseeds, though plants may not be true to form because of hybridization. Portulaca has few pests but is occasionally affected by mealy bugs. Commercial insecticidal soaps control mealybugs; test a section before wide application in case of plant injury. Follow label instructions closely.