How To Grow And Care For Portulaca

Ground-hugging portulaca puts on a garden celebration all summer long. "Portulaca grandiflora," which, in Latin means "large-flowered," adds a profusion of brilliant blooms to any garden. 

The flowers of portulaca close at night and reopen the next morning. Its lush succulent leaves and vibrant colors evoke a sense of the tropics. Bees, butterflies, and hummingbirds are attracted to its showy flowers. The slow-spreading, low-maintenance xeric plant thrives in even the hottest, driest summers. Stunning in a row of hanging baskets on the porch or spilling over a rock wall or a path, you can plant it and almost forget it thanks to its low-water needs. Add this to your landscape in late spring and it will be teeming with repeat blooms from spring through fall. All parts of portulaca are toxic to dogs, cats, and horses.

Plant Attributes

Care

Portulaca makes an excellent ground cover or hanging basket. With up to a 2-foot trailing spread of blooms, the tender foliage adds interest to walls and rock gardens. It does well in any well-draining soil, and you can tuck a few stems into the smallest nooks in a stone wall.

Space plants from 8 to 12 inches apart at the front of a border when planting in the garden. Allow the soil to dry between waterings and fertilize lightly if at all.

Light 

Portulaca thrives in full sun. Given at least six to eight hours of sun daily, it will bloom prolifically from late spring through fall. On cloudy or rainy days, the blooms stay closed. The flowers reopen with the arrival of bright sunlight.

Soil

Portulaca likes sandy soil but will tolerate a variety of soils; however, a light soil with good drainage is key to healthy plants. Portulaca prefers average to lean soil fertility and doesn't mind shallow or rocky soil. In containers, use a well-draining potting mix. In the landscape, amend soil with course sand or organic matter to improve drainage where needed. Heavy clay soils can lead to crown rot, so plant in containers instead. This plant is moderately salt tolerant and good for coastal gardens.

Water 

With shallow roots and moisture-retaining leaves, portulaca is exceptionally drought-tolerant and only requires watering when the top layer of soil has dried out. The plants will grow and bloom more vigorously when they receive about an inch of water per week. Overwatering can lead to rot, especially in poorly drained soils.

Temperature and Humidity 

Summer-loving portulaca can withstand high heat and dry weather conditions. It tolerates the high humidity of the Southeast but suffers with too much moisture. This flowering annual does not survive frost and isn't available until late spring or summer in most of the South. In southern Florida and other Zone 10 gardens, it can be planted earlier in spring or in late fall.

Fertilizer 

Minimal fertilizer is needed for portulaca as it typically withstands neglect. An all-purpose, slow-release flower fertilizer can be applied mid-summer to encourage new growth if desired. Too much fertilizer may prevent blooming.

Types Of Portulaca 

Portulaca is often sold without a cultivar name and simply labeled by the species P. grandiflora, P. oleracea, or P. umbraticola, though most are likely hybrids. P. grandiflora, or moss rose, has needle-shaped foliage. Some come with double flowers. P. umbraticola is sometimes called wingpod purslane because of its oblong leaves. P. oleracea, or common purslane, has flattened, oblong leaves and has naturalized as a weed in many areas. The hybrids sold at garden centers are much more ornamental. Here are a few popular series:

• P. umbraticola Mojave: This series includes large, single-petaled flowers in cherry red with yellow centers, bright tangerine with yellow centers, and a sunny yellow version. The plants do not require deadheading.
• Sundial Mix: This popular seed mix of moss rose has 3-inch, double blooms in fuchsia, pink, orange, scarlet, yellow, and white.
• Fairy Tale series: Fairy Tale's bi-colored flowers have a pom-pom of petals in the center and flat outer petals. The leaves are flattened. ‘Cinderella’ has yellow petals and a hot pink center.
• P. grandiflora Happy Trails: This series has big, double blooms and comes in fuschia, orange, a pink-streaked peppermint, white, and purple-pink Rosita.

Pruning

Portulaca doesn't require much pruning. However, if you want to shape or contain the plant, you can prune as much as you like. While spent blooms fall off, you can pinch them back to encourage new ones or to prevent the plant from spreading seed. Deadheading the plants may encourage them to bloom later into fall.

Propagating Portulaca  

Portulaca is very easy to propagate during the summer when you prune your plants. Taking cuttings can promote bushier growth as well as providing you with new plants. Follow these steps to propagate stem cuttings:

1. Using sharp, sterile snips or pruners, take stem cuttings of 2 to 4 inches from the tips.
2. Remove any spent blooms or buds and remove leaves from the bottom half of the stem. 
3. Dip the cut end into rooting hormone and stick into moist soil in the garden or a pot.
4. Water enough to keep the soil consistently moist but not waterlogged. The cuttings should root in one to two weeks. Once new growth is visible, cut back to regular watering.

How To Grow Portulaca From Seed 

Outdoors, seeds can be started in the landscape after the last frost. You can enjoy blooms sooner if you sow seeds inside in a sterile seed-starting mix indoors six to eight weeks before your last frost. Germination is most successful when the soil temperature is 70-75° F.

1. Scatter seeds over moist, well-draining soil and press lightly to make contact with the soil. The seeds germinate best when exposed to light.
2. Water to keep soil lightly moist until growth is visible. Keep indoor seedlings in a bright window or under grow lights. Seedlings germinate in 10-14 days.
3. After the danger of frost has passed, harden off indoor seedlings, gradually exposing them to outdoor temperatures and sunlight.
4. Transplant into the garden or a larger container, being careful not to disturb the roots.

Potting And Repotting Portulaca

Portulaca is shallow-rooted and does not need a deep container. Containers must have adequate drainage. Use a lightweight potting mix, adding perlite if needed to improve drainage. Arrange plants closely together and allow the foliage to trail over the sides for a fuller look. Allow the top layer of soil to dry between waterings. Portulaca may be repotted, but its roots are sensitive to disturbance.

Overwintering 

Portulaca are annuals that grow, flower, and set seed in only one growing season. They do not survive frosts. If you allow your portulaca to set seed, you may see new seedlings emerge the following spring.

Common Pests & Plant Diseases

Portulaca can be subject to common pests like thrips, aphids, mealybugs, or spider mites. You can spray water on the plants to dislodge pests or spray foliage with insecticidal soap. Birds, squirrels, or chipmunks may eat portulaca because it retains water in its leaves.

Overwatering or poorly drained soil can lead to root rot, crown rot, powdery mildew, or a gray mold called botrytis. Portulaca is susceptible to these or other fungal issues if conditions are too moist or they are planted in areas with poor air circulation. Diseased sections should be removed and disposed of. Water early in the day to allow soil to dry out before cooler evening temperatures.

How To Get Portulaca To Bloom

Portulaca blooms best in full sun, or at least six to eight hours of direct sunlight a day. Shade may prevent blooming, and flowers won't open in dim lighting. Over-fertilizing the plants can also interfere with blooming. On some varieties, deadheading can help prolong the bloom season into fall.

Common Problems 

Portulaca has few issues outside of those caused by overwatering or pests. Here are two common problems that gardeners face.

Lanky Growth

Portulaca is a trailing plant that can naturally become lanky, especially by the end of summer. Seedlings and 4-inch containers can be planted closely together—about 6 inches apart—to achieve a fuller look. You can also pinch back stems for a bushier looking plant that will produce more flowers.

Fuzzy White Tips On Stems

These white hairs are exposed when flowers drop and can indicate the plant is going to seed. Snip off the tips of stems to encourage more flowering.