HARDINESS: Frost tolerant
PREFERRED SOIL pH: Adaptable
PREFERRED SOIL TYPE: Average
PREFERRED LIGHT: Sun
ATTRIBUTES: Flowers in many colors for hot, dry spots; as ground cover and edging, in pots and baskets
SEASON OF INTEREST: Summer
FAVORITES: Sundial series for spreading habit; Margarita series for compact plants
QUIRKS: Flowers close in the evening and during rainy weather
GOOD NEIGHBORS: Gladiolus, larkspur, petunia, scabiosa
WHERE IT GROWS BEST: Hot, sunny site; well-drained soil
POTENTIAL PROBLEMS: Root rot in soggy soil Excellent
CRITTER RESISTANCE: Bedding plants, seeds
SOURCE DIMENSIONS: 6 in (15.2 cm) tall, 10-16 in (25.4-40.6 cm) wide
Portulaca in the Landscape
Portulaca is a flowering annual that thrives where others shrivel, perking up seemingly hopeless sites with a summer-long supply of 2 in (5.1 cm) diameter, delicate-looking double blossoms atop fresh, succulent foliage. They bloom in colors ranging from deep magenta and many shades of orange and yellow to white, salmon, and a peppermint pink color that's patterned with frosty white.
In fact, recent improvements in portulaca are so dramatic that portulaca's status has been raised from a fill-in plant for problem spots to a featured flower in beds, containers, and even hanging baskets. Portulaca spreads out to form soft mounds of delicate, succulent foliage. It is ideal for planting in broad bands along a sun-baked walkway, for spilling over warm stones atop a wall, edging a bed filled with taller flowers, or for bedding alongside roses or other bare-stemmed shrubs.
Growing care-free portulaca does require a few special considerations. The flowers open wide in bright, sunny weather and close during rainy weather, and at night. While open, flowers attract honeybees, so avoid stationing a planting right next to a doorway or other high-traffic area. Portulaca often reseeds, and even hybrids produce offspring well worth keeping. Best of all, portulaca is a champion at withstanding drought, capable of going without water longer than almost any other garden flower.
The Sundial series has earned a well-deserved reputation for beauty and dependability. Its color range is outstanding, too, particularly if you like soft sherbet shades like 'Peach' and 'Mango'. Sundial portulacas grow 6 in (15.2 cm) tall and spread 14 in (35.6 cm) wide, which makes quite a sight when they're allowed to cascade over the top of a wall or large container. The Margarita series is similar in its mix of colors, but the plants form more compact mounds only 10-12 in (25.4-30.5 cm) wide.This makes Margarita portulacas perfect for use as an edging or a blooming ground cover in sunny spots.
Inexpensive bedding plants of portulaca are easy to find in garden centers in spring, or you can start seeds indoors 4-6 weeks before your last frost. Seeds have a wide tolerance for germination temperatures, so you can even sow them outdoors in beds or containers in late spring. Sow the tiny seeds on top of the soil, barely pressing them in, because they need light to germinate. There is no great hurry to get seedlings started because they grow best in warm or even hot weather. And although established plants tolerate drought very well, it's important to provide enough moisture to young plants to support strong, steady growth. Ideally, you should allow the soil to become barely dry between waterings.
Portulacas are not heavy feeders, but they will stay in bloom longer if you drench them with a soluble all-purpose fertilizer, applied according to package directions, monthly during the summer. Should the plants eventually become thin and leggy looking, you can shear them back by about half their size to force out fresh new flowering stems.
True to their care-free character, portulacas are ordinarily impervious to insect attack and diseases, only succumbing to root rot in soggy soil. If this happens set healthy plants in a new location with well-drained soil.