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Planting and Growing Moss Roses

Portulaca grandiflora is a succulent flowering plant, eleven o'clock, Mexican, moss, sun, table, rock rose in yellow, red, white, pink, purple bright colors. Summer.
Image Credit:
Svetlana CA Countryside
Botanical Name
Portulaca grandiflora
Life Cycle
USDA Zones
Sun Exposure
Water Needs
Height
Spread
Soil pH
Bloom Time
Plant Type
Written By: Jennifer Keating Digital Editor
Almanac Guide to Herbs

Bring vibrant color to your garden with the Moss Rose! This low-maintenance annual thrives in the hot sun and boasts cheerful blooms in a rainbow of hues. Learn how to grow Moss Rose from seeds or cuttings, and discover easy tips for watering, fertilizing, and keeping your plants blooming all summer!

Portulaca grandiflora demands little in terms of care but spreads joy and delight wherever it grows—as long as the Sun shines. 

“The saucer-shaped, rose-like flowers are produced on the stem tips, held facing up above the foliage, opening from buds that resemble little popcorn kernels. They are only open in bright sunlight, closing at night and on cloudy days, but most of the newer hybrids will remain open throughout the day,” explains Susan Mahr of the University of Wisconsin–Madison.

Moss Rose Flower, Portulaca Moss Rose, Portulaca grandiflora Flowers, Colorful flowers

Planting

Purchasing seedlings or starter plants may jump-start moss roses’ flowering period, but they can also be grown from seeds or propagated through cuttings from established plants. 

Starting Moss Rose From Seeds

Start seeds in seed-starting mix indoors 6 to 8 weeks before the last frost. Cover minimally; moss roses need sunlight to germinate. Learn to make your own seed-starting mix.

Dampen and maintain moisture. Plants germinate in about 10 to 14 days in 70° to 85°F temperatures. 

moss rose seeds
Moss Rose seeds resemble tiny grains of pepper.
Photo: Melissa Crotts

Propagating Moss Rose

To propagate from a cutting, prepare damp potting mix. Trim off a 3-inch piece of the plant and remove any foliage from the last inch of the cut end. Insert the cut end into the potting mix. Maintain even moisture until new growth appears, 

Transplanting Moss Roses

Be aware that moss rose transplants need special care: The night before transplanting, water to ensure that the plant is hydrated so that soil will cling to its shallow roots. Lift with a spoon or small spade (depending on plant size), including the soil surrounding the plant. 

Space plants 6 to 12 inches apart; crowded plants flower poorly. Replant, with roots only just below the soil’s surface, as soon as possible. 

Water lightly and keep moist until new growth appears (a sign that the plant is established). Moss rose’s shallow root system means that water is important until plants get going. Afterward, too much water can cause rot, which is why well-draining soil is essential.

Yellow moss-rose purslane (Portulaca grandiflora)
Yellow moss-rose purslane (Portulaca grandiflora)

Growing

Moss rose is drought-tolerant but benefits from watering when the top inch of soil is dry.

Provide 6 to 8 or more hours of sunlight per day; warm temperatures are ideal. Shade may reduce blooms.

Deadhead to stimulate more blooms or to deter self-seeding, if desired. If plants become leggy, pinch stems back and provide a diluted dose of balanced fertilizer. New growth and blooms should follow.

bee on moss rose flower
Pollinators love moss roses!
Photo: Melissa Crotts

Pests and Problems

Diseases: none serious; sometimes Botrytis blight, damping off, Pythium root and stem rot, Rhizoctonia root and stem rot.

Pests: aphids, slugs/snails.

Wit and Wisdom

  • Portulaca oleracea, common purslane with flat, fleshy leaves that is sometimes grown as a vegetable and often considered a weed, is known as “moss rose.” You can eat purslane! Learn more.
  • Portulacas have been grown in American gardens since the 1700s.
  • “Portulaca” comes from the Latin words porto, meaning “to carry,” and lac meaning “milk,” referring to the milky sap of some species.

About The Author
Jennifer Keating

Jennifer Keating

Digital Editor

Jennifer is the Digital Editor at The Old Farmer’s Almanac. She is an active equestrian and spends much of her free time at the barn. When she’s not riding, she loves caring for her extensive collecti...