How to Grow: Moss Rose

Portulaca grandiflora

Other Name

Flowering purslane

Sun Requirements

full sun

Bloom Period and Seasonal Color

Mid summer until fall in colors such as yellow, orange, white, pink, red, and bi-colors

Mature Height x Spread

6 to 10 inches x 6 to 12 inches

Added Benefits

drought tolerant

Moss roses’ name describes this annual beautifully. The plant is a low growing, spreader, like moss, with succulent leaves that remind you of a plant in the cactus family. The flowers do look like miniature roses, especially when growing double-flowered varieties. Moss rose features bright, vivid colored flowers so they shine in a container or garden bed. Moss rose is drought tolerant and loves the heat, so it’s perfect for small pots, sunny, dry areas in the yard and specialty gardens such as rock gardens. In New England, the more sun and heat the better for these plants. They aren’t an aggressive spreader so they grow well in small spaces without overwhelming other flowers.

Where, When and How to Plant

Plant moss rose seeds directly into well-drained soil in a full sun location. Don’t grow moss rose on heavy, clay soils or soils with poor water drainage. Barely cover the small seed as they need light to germinate.  You can also start seeds indoors 8 weeks before your last frost date or buy transplants locally and transplant seedling outdoors. Try to space plants about 6 to 12 inches apart so they aren’t overcrowded. Overcrowded plants won’t flower as well.

Growing Tips

Moss rose have shallow root systems, so keep plants well watered the first few weeks until established. Once established, they are drought tolerant.  However, too much water will cause the plants to rot, so be sure you have good drainage. Moss rose doesn’t require fertile soils and rarely need extra fertilizer to thrive. In fact, fertilizer can cause a delay or lack of flowering.

Regional Advice and Care

Don’t rush your moss rose plants or seeds into the garden. Let the soil warm and plant in early June. Come mid summer, the plants may get leggy and have few flowers. Pinch back the stems to a side shoot, add a small dose of fertilizer, and they should re-grow and flower more for late summer and fall. Moss rose also don’t compete well with weeds or other flowers. Grow moss rose where there’s plenty of space and keep the bed well weeded. Moss rose self sow readily so don’t be surprised if you see seedlings in the same areas the following spring.

Companion Planting and Design

Grow moss rose in containers, railing planters or window boxes. They look great in the shallow soils of a rock garden, in front of a flower border or even trailing out of a hanging basket or over a wall. They look good paired in a container with taller annuals with contrasting flowers and foliage such as salvia.

Try These

The ‘Sundial Series’ features 6 inch, tailing plants with brightly colored, rose-like blooms. ‘Happy Hour Series’ flowers a few weeks earlier than most moss rose varieties with mounding, 1 foot wide plants.

Excerpted from my book, New England Getting Started Garden Guide.