Moss rose, Portulaca grandiflora, is a heat tolerant annual.
Moss rose, Portulaca grandiflora, is a drought and heat tolerant annual native to hot, dry plains in Argentina, southern Brazil, and Uruguay. This herbaceous plant in the purslane family (Portulacaceae) is cultivated throughout the world as a garden annual for its showy flowers that bloom all summer long with little care. It is related to the weed purslane (P. oleracea), and like that plant has escaped to naturalize in some parts of the country on roadsides and in waste places. In the ornamental industry moss rose may be listed as P. oleracea, P. umbraticola or P. grandiflora, but many cultivars are likely hybrids.
Moss rose has fleshy, succulent leaves and stems.
Moss rose is a semi-succulent plant that stores water in its fleshy leaves and stems. The bright green leaves are oblong to cylindrical with pointed tips. They are up to an inch long and are arranged alternately or in small clusters along the reddish, multi-branched prostrate to slightly ascending stems.
A moss rose with flat leaves.
P. oleracea and hybrids with that species have flat leaves.The stems can be somewhat fragile and break easily (although broken pieces will root if the soil is moist enough). The low-growing plants form a mat up to a foot across and 3 to 8 inches high arising from the central fibrous root system.
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.
The solitary flowers open from small buds (L) and may be single (C) or double (R).
When open the flowers can nearly hide the foliage. Flowers come in white and a wide range of warm colors, including pink, peach, yellow, orange, red, fuchsia, magenta, lavender and purple. Newer cultivars and hybrids offer a greater range of shades than in the species, and some are striped or spotted with contrasting colors. Each flower has 5 paper thin petals, although semi-double and double types have been developed with multiple sets of petals. The petals surround a group of 40 or more stamens and 5 to 8 stigmas in the center. Depending on the variety, flowers can be 1-3 inches across.
Seed capsules following the flowers are filled with tiny black seeds.
After pollination, rounded 1/8-1/4 inch diameter seed capsules develop. When ripe, they split open, spilling numerous tiny, rounded to elongate, iridescent blue-grey seeds from the each capsule. Moss rose often reseeds. The seeds are edible raw or cooked (although it would be time consuming to collect enough to use as food!).
Moss rose makes a good bedding plant in hot, dry areas where other plants struggle. It can be used as an edging plant along walkways, as an annual groundcover en masse, or interplanted in bulb beds to cover the ground after the bulb foliage dies back. It will grow in between rocks and flagstones (but does not tolerate any foot traffic), and looks nice draped over stones in a rock garden or in the cracks in a rock wall.
Use moss rose as a ground cover for hot areas.
It combines well in containers with other plants that also thrive in hot, sunny sites such as nasturtium and zinnia. The fine texture of moss rose contrasts well with the bold rounded leaves of nasturtium, while its short stature contrasts with all types of zinnias. In containers the brightly colored blossoms show up nicely when planted with ornamental sweet potato vine in either lime green or dark purple (but be aware that the vigorous growth of the sweet potato could easily overrun the smaller moss rose, especially when planted in the ground). Moss rose can also be used in hanging baskets as a trailing plant hanging over the edge of the container.
Grow moss rose in full sun in most soil types as long as they are well-drained. It is a good choice for lean, sandy, gravelly or rocky areas. Grow from seed sown directly in the ground or started indoors 4-8 weeks before the average last frost for earlier bloom. Just barely cover the tiny seeds whether sown indoors or out.
Plant moss rose in full sun.
Mixing the tiny seeds with sand before sowing will make it easier to scatter them uniformly. Seeds should germinate in 1½-2 weeks. Because they are frost tender, wait until the soil is warmed and the danger of frost has passed to seed or transplant into the garden. Thin the seedlings to 3 inches or more apart. Established plants can also be propagated by cuttings. Although moss rose survives difficult conditions, plants will produce more lush growth and flowers when provided sufficient moisture and rich soils. Pinching or deadheading will promote greater flowering and reduce reseeding. Plants can be pruned or sheared in midseason if they begin to look straggly for a neater appearance and to promote fuller growth.
Moss rose has few pest problems, although occasionally aphids or slugs can be a problem. Stem or root rots can be a problem in wet soils. This plant is not favored by deer in most places.
Seeds are offered as single varieties and in mixtures. Many types are available as bedding plants in garden centers and from other retailers in the spring. Some common varieties (although more are always being developed) include:
- ‘Afternoon Delight’ has 2 inch flowers that stay open longer in the afternoon than the species.
- ‘Calpyso Mix’ has bright double flowers in shades of yellow, red, pink, orange, purple and white.
- ‘Duet’ offers bicolor single flowers on compact, free-flowering plants.
- The ‘Fairy Tale’ series flowers have a pom-pom of petals in the center and flat outer petals in bright colors. Although listed as P. grandiflora, it has the flat leaves typical of P. oleraceae. The cultivars in this series have appropriate names, such as ‘Cinderella’ for the bicolor yellow and red one, ‘Snow White’ for the all-white version and ‘Sleeping Beauty’ for the yellow.
The ‘Happy Hour’ series, bred for reduced photoperiod requirement (so it will bloom earlier), comes in 8 vivid colors with tropical names like banana, coconut, lemon, orange and rosita. The plant has a fuller habit than most moss roses and has large, double blooms.
- ‘Margarita’ is a series of compact, mounding, early-flowering plants with flowers in shades of red, pink, orange, white, yellow and purple.
- ‘Mojave’ series has large white, pink, red, tangerine, and yellow flowers.
‘Fairy Tales Cinderella’
The ‘Rio’ series is mix of 6 separately patented culitvars with large, brightly colored flowers.
- ‘Sundance’ has semi-double flowers in four colors that remain open most of the day.
- The ‘Sundial’ series is early blooming, with double flowers that open in cooler and cloudier weather. The compact plants come in nine colors (which may be available separately rather than only in a mixture) including ‘Fuchsia” with magenta-pink flowers, ‘Peppermint” with hot pink-striped white flowers, and white, pink, peach, ‘Mango’ (orange), red and yellow.
The Tequila™ series are hybrids with flowers in a mix of colors, such as the red which is red on the outside and yellow in the center. It has been shown to be slightly more tolerant of cool and moist conditions than other types, and is slightly less daylength sensitive than other varieties. It was replaced by the Happy Trails series in 2013, with additional colors which were not available in the Tequila series and a shorter miniumum photoperiod (so will bloom earlier).
- The ‘Yubi Summer Joy’ series includes several colors. All have single blossoms that are nearly three inches across and remain open late in the day. Plants are more trailing and have broad leaves.
– Susan Mahr, University of Wisconsin – Madison
- No Flowers On Portulaca – Why Won’t My Moss Rose Flower
- When Portulaca Won’t Bloom
- Moss rose
- Moss Rose
- Garden Plans For Moss rose
- Colorful Combinations
- Moss Rose Care Must-Knows
- More Varieties of Moss Rose
- Plant Moss Rose With:
- Portulaca Flower: Tips For Portulaca Care
- How to Grow Portulaca Plants
No Flowers On Portulaca – Why Won’t My Moss Rose Flower
My moss rose plant doesn’t bloom! Why won’t my moss rose flower? What’s the problem when portulaca won’t bloom? Moss roses (Portulaca) are beautiful, vibrant plants, but when there are no flowers on portulaca, it can be disappointing and downright frustrating. Read on for possible reasons and solutions when there are no flowers on moss roses.
When Portulaca Won’t Bloom
When a moss rose plant doesn’t bloom, there may be problems with the growing conditions. Although portulaca is an amazingly low-maintenance plant that thrives on neglect, it still has certain requirements for healthy growth.
Drainage: Moss roses prefer poor, dry, well-drained soil. If portulaca won’t bloom, it may be because the soil is too rich or too soggy. Although you can add sand or a small amount of compost to the soil, it may be easier to start over in a new location. (You can also plant moss roses in containers. Use a well-draining potting mix and be sure the pot has a drainage hole in the bottom.)
Water: Although moss roses thrive in difficult conditions, they still benefit from a regular drink of water. As a general rule, one deep watering per week during hot, dry weather is sufficient. However, a little extra water won’t hurt if the soil drains freely.
Sunlight: Moss roses thrive in intense heat and punishing sunlight. Too much shade may be to blame when there are no flowers on moss rose. As a general rule, portulaca needs six to eight hours of sunlight per day.
Maintenance: Deadheading may be impractical when moss roses are in full bloom, but removing old blooms is extremely effective for stimulating new blooms on a poorly blooming plant.
Pests: Aphids are tiny pests that can wreak havoc when they attack a moss rose plant en masse. Unfortunately, spider mites, which love dry, dusty conditions, may be responsible when a moss rose plant doesn’t bloom. Mites are easy to spot by the fine webbing they leave on the foliage. Both pests are easy to treat with regular applications of insecticidal soap spray. Apply the spray in the morning or evening when temperatures are cool and the sun isn’t directly on the plant.
If you need to cover hot and sunny ground or you’re tired of watering your hanging baskets every day all summer, look no further than moss rose! Whether you call it moss rose, portulaca, or purslane, this plant is tough as nails and can stand up to almost anything. And with a trailing habit and nonstop bloom power, it looks great in so many settings.
Garden Plans For Moss rose
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Moss rose comes in many colors—there is almost no end to the amount of combinations you can make with this plant. The blossoms of moss rose generally come in bright, vibrant jewel tones, but there are mild pastel options as well. Blooms are typically single flowers with five petals and a pom-pom of yellow stamens in the center. However, there are many variations. You can also find semi-double blossoms that have a few extra rows of petals. Also, fully double flowers exist that are many petals together with no visible stamens in the center.
If the many different varieties of petals to choose from weren’t enough, there are also many variations of colors on the surface of the petals as well. Most commonly, the flower colors are a single color on all of the petals with the yellow center. There are also flowers with “broken color,” where a solid colored petal is randomly streaked through with a secondary color. There are also other forms of this broken color patterning where the outside of the petal is one color with a splash of a second color in the center—it’s truly unique!
The foliage of moss rose is fairly simple. These plants are adapted to dry conditions, so they have very fleshy, succulent leaves. These leaves store up water to use at a later time, and in very dry conditions, they may even fold up their stems to help with water loss. The leaves on moss rose can be different shapes, too. Some varieties, generally the ones derived from the species P. grandiflora, are needle-like, while others are more paddle-like in shape.
Tips on Landscaping with Roses
Moss Rose Care Must-Knows
Moss rose is an extremely easy plant to grow, almost to the point of becoming weedy. The biggest thing to consider when planting moss rose is location. Moss rose hates wet areas, and one of the few ways to kill this plant is by overwatering. Moss roses are adapted to dry, desert-like conditions. Because of this, it may take them a little time to get going in a cool, moist spring—but once the summer heat kicks in, these plants will be off to the races! Moss rose also grows well in slightly salty soil.
Another great thing about this plant is that it doesn’t require any deadheading. Moss rose will keep blooming all season long with no additional care needed. However, the plants do produce large amounts of seed, so you may see volunteers coming back each year if you plant them once. Luckily, it’s easy to weed out any unwanted seedlings. See our annuals care guide.
More Varieties of Moss Rose
Sundial Fuchsia Moss Rose
Portulaca ‘Sundial Fuchsia’ offers bold magenta-pink on compact, heat-resistant plants.
Sundial Peppermint Moss Rose
Portulaca ‘Sundial Peppermint’ offers white blooms liberally striped with hot pink.
Sundial White Moss Rose
Portulaca ‘Sundial White’ bears showy double white blooms all summer long.
Sundial Yellow Moss Rose
Portulaca ‘Sundial Yellow’ bears showy double golden-yellow blooms all summer.
Plant Moss Rose With:
Nasturtiums are so versatile. They grow easily from seed sown directly in your garden’s poorest soil and bloom all season until frost—and they are never greedy about food or fertilizer. Nasturtiums are available in either spreading or climbing types. Plant spreading types in large containers to spill over the sides or alongside wide paths to soften the sides for a romantic look. Use nasturtium to brighten a rock garden or between paving stones. Plant them at the edges of beds and borders to fill in between other plants and add soft, flowing color. Train climbing types up trellises or alongside fences. The leaves and flowers are edible; use them as a showy plate garnish or to jazz up salads.
Want fast color for just pennies? Plant zinnias! A packet of seeds will fill an area with gorgeous flowers in an amazing array of shapes and colors—even green! And it will happen in just weeks. There are dwarf types of zinnias, tall types, quill-leaf cactus types, spider types, multicolor, special seed blends for cutting, special blends for attracting butterflies, and more. Zinnias are so highly attractive to butterflies that you can count on having these fluttering guests dining in your garden every afternoon. But to attract the most, plant lots of tall red or hot pink zinnias in a large patch. ‘Big Red’ is especially nice for this, and the flowers are outstanding, excellent for cutting. Zinnias grow quickly from seed sown right in the ground and do best in full sun with dry to well-drained soil.
Among the most popular container-garden plants, sweet potato vine is a vigorous grower that you can count on to make a big impact. Its colorful foliage, in shades of chartreuse or purple, accents just about any other plant. Grow a few together in a large pot, and they’ll make a big impact all on their own. Sweet potato vines do best during the warm days of summer and prefer moist, well-drained soil. They thrive in sun or shade.
Portulaca Flower: Tips For Portulaca Care
By Stan V. Griep
American Rose Society Consulting Master Rosarian – Rocky Mountain District
A truly beautiful low growing ground cover type plant is called the portulaca (Portulaca grandiflora), or sometimes known as the sun rose or moss rose. Portulaca plants are native to Brazil, Argentina and Uruguay. Portulaca flowers are easy to grow and enjoy. Let’s look at what is needed for portulaca care.
How to Grow Portulaca Plants
Portulaca flowers tolerate many kinds of soil but prefer sandy, well-drained soil and love the full sunlight. These plants are excellent for high heat and drought tolerance, and will seed and spread themselves very well. Some control methods may be needed to keep portulaca plants from becoming invasive to areas where they are not wanted. From personal experience in my garden areas, I can tell you that these wonderful plants do spread easily and very well. I planted some seeds in the gravel mulch at the end of one of my rose beds and the following summer had portulaca plants coming up in several other areas where I had not planted any such seeds.
You do not need to water often for proper portulaca care. The cylindrical foliage of the portulaca flower retains moisture very well, thus, regular watering is not needed. When they are watered, just a light watering will do, as their root zone is very shallow.
When planting the portulaca seeds, it is not necessary to cover the seed at all and, if covered, only very lightly as they need the sun to sprout and grow. The seeds planted in the gravel mulch in my rose bed were scattered by hand over the gravel and the gravel lightly rocked back and forth with my hand to help the seed reach the soil below.
Portulaca flowers are truly beautiful in various garden and landscape settings and have been used to beautify old structures and stone walkways, as they grow well in the old cracks in the structures where winds have deposited just enough soil to support them. Portulaca flowers are beautiful growing around the stones of a garden path with their mix of beautiful colors of pink, red, yellow, orange, deep lavender, cream and white.
These wonderful plants will help attract butterflies to your gardens as well as acting as eye-catchers for your gardens or landscapes. They may be planted in containers as well such as whiskey barrel planters and hanging baskets. The portulaca plants will grow out and over the edges of the containers, making a grand display of their cylindrical somewhat moss like foliage and truly strikingly vibrant colored blooms.
One word of caution though, the area around and underneath where the hanging baskets or other containers are located can easily be populated by more portulaca plants the next summer from the seeds spread by the plants the previous year. This, too, has been the case in my personal experience with this very hardy plant. While portulaca is an annual, they do indeed come back every year without any further help from me.