Plant library · Annual Flowers
Portulaca grandiflora
Moss rose is a low, spreading annual flower that brings jewel-tone bloom to the front edge of sunny planting areas from early summer into fall. Its succulent groundcover habit stays about 6 inches tall while reaching roughly 1 foot across, so it reads as a close-to-the-ground color layer rather than a vertical accent. Use it where a planting needs a bright, low-water finish without blocking views or edging.
Place moss rose at the open front of a border, along a sunny bed edge, or in gaps beside paving where its low profile will not interfere with circulation. It also suits containers, hanging planters, rock gardens, crevices, slopes, and the top of a low wall, where spreading stems can soften a hard edge. Keep it out of spaces intended for taller seasonal flowers; nearby plants can quickly shade this short annual and hide its blooms.[1][2]
Set plants 1 foot apart, center to center. Each plant can spread to about 1 foot wide, so that spacing allows adjacent plants to meet into a continuous, low planting without substantial overlap. For a narrow edge, use a single row set back slightly from the path or curb so the mature mat remains within the bed. In larger beds, repeat the 1-foot grid to make a broad carpet of color.
Reserve the sunniest, fastest-draining part of the plan for moss rose. It is suited to full sun and low-water planting, including sandy, rocky, or otherwise lean ground that does not stay wet. Avoid low pockets, downspout zones, and heavily irrigated bed sections. A raised edge, gravelly strip, rock garden, or freely draining container gives this annual a more appropriate rooting space than a moisture-retentive border.[1]
Bloom begins in early summer and can continue into fall, giving a long seasonal role at the base of sunny beds and containers. As an annual, it occupies its space for one growing season; plan to replant the area or shift the design after frost ends the display. Its flowers may close overnight and during cloudy or rainy weather, so place it where sunny-day color is the main goal.[1][2]
Do not rely on moss rose to provide constant visible bloom in shaded weather, since flowers commonly close when light is low. Its low, prostrate habit also means it is easily overtopped by vigorous neighbors. Give it an exposed front-row position with clear overhead light, rather than tucking it beneath taller annuals or dense perennials.[1][2]
Editorial content updated 2026-07-20.