How to Grow and Care for Portulaca, Also Known as Moss Rose

Portulaca grandiflora, also known as Moss Rose or Sun Rose, is a hardy, low-growing annual that is native to South America. In the summer, it can produce vibrant flowers in a rainbow of colors, including pink, yellow, and white. Portulaca is relatively easy to grow under the right conditions, and these small, bright blooms will add plenty of color to your garden's sunny spaces. But before you start planting, it's important to note that the pretty flowers can actually be toxic to dogs, so be sure to add these annuals only to spots where your furry friends won't be able to reach them.

What Is Portulaca?

Portulaca is a plant with low water needs that has been hybridized to produce plants that bloom in a wide range of colors, according to Justin Hancock, a horticulturist with Costa Farms. "Flowers typically appear in shades of pink, red, orange, yellow, and white, as well as bi-colors (white-on-pink, orange-on-yellow, etc)."

What Are the Ideal Conditions for Growing Portulaca?

This plant does best in full sun—at least six hours per day—and needs direct sunlight in order to bloom, but other than that, it's not too picky about its growing conditions as long as it's dry. "You can treat it like most other annuals (such as geraniums or zinnias) in terms of water, or you can treat it like a succulent, only watering during periods of drought," Hancock says, adding that these low water needs also make it a fine choice for hanging baskets since they tend to try out faster than landscape beds and borders. "In terms of soil type, just about any soil will do, except for one that stays wet."

Because Portulaca thrives in full sun and sandier well-drained soil, it is considered hardy in USDA hardiness zones two to eleven according to Chia-Ming Ro, founder of Coastal Homestead. "In zones two to nine they are grown as annuals due to the frost, however they drop seeds and have proven to often come back as the weather warms up," she explains. "In zones 10 to 11 it is known as a perennial."

How to Grow Your Portulaca at Home

If you want to add Portulaca to your garden, you can do so either by purchasing a mature plant from the nursery or starting some from seed. "Nursery-grown plants will typically be in bloom when you purchase so that gives you the opportunity to select the colors you'd like," says Hancock. "It also gives you a head start since the plants will be blooming when you're ready to plant in spring (after the danger of frost has passed in your area; moss rose isn't a frost-tolerant plant.)" If you want to start from seed, Ro says they only need to be covered with a small amount of loose soil in order to sprout.

How to Give Your Flowers a Boost

Although not required, you can amend the soil around your plants to give the blooms a boost. "Portulaca doesn't require much care at all," Ro says. "However, if you do wish to fertilize, you can use a general purpose fertilizer year round and a fertilizer higher in phosphorus right as buds emerge to encourage more blooms."

Pests, Problems, and Pollinators to Know About

Your Portulaca will likely attract pollinators like bees and butterflies, but it's unlikely to bring any unusual or destructive visitors to your yard. "It may be nibbled on by deer, rabbits, or other herbivore pests, but no more or less so than the typical garden annual," says Hancock.