Portulaca, Moss Rose

Heat Tolerance: Excellent

Sun Exposure: Full sun

Origin: Brazil

Growth Habits: Tender annuals 6 inches tall (15 cm), 14 inches in spread (35 cm)

Flowers: White, yellow, light orange, pink or red flowers

Watering Needs: Occasional watering is OK, but they do better with a regular supply of water.

Propagation: Seeds

Rose Moss is a nice ground cover for dry areas, borders and beds in the sun. It also makes a good hanging basket plants. The 1 inch wide (2.5 cm) flowers close in the afternoon to reopen in the morning.

Portulaca grandiflora, Britton, N.L., and A. Brown. 1913. Illustrated flora of the northern states and Canada. Vol. 2: 41.

Culture:
Sow in place after the last frosts (end of February in Phoenix). The seed is very fine, and should be mixed with sand to ensure a regular distribution. Do not cover the seeds. The plants can also be started indoor at 70 to 85°F (21 to 29°C) in January, to be planted in March 12 inches apart (30 cm). In colder climate, the plants should be set out in summer, 2 to 3 months after the last frost date. Planting when the weather is still cool might dwarf the young plant and prevent them to develop fully, even as the temperature gets more appropriate for them. With enough heat, the young plants get easily established in their new location. Remove the plants when they start weakening (or freeze) in fall or early winter. Since they don't freeze in Phoenix, the plants look like they might be left in place maybe trimmed and would start again in the spring. In fact, they are annuals and will keep weakening over the winter, looking weedier until they finally die in late spring. It is much better to remove them when they stop blooming.