Portulaca grandiflora
Rose Moss
Common names: Purslane, Sun Rose, Moss Rose, Large-flowered Portulaca
At a glance
- Light
- Full sun
- Pot size
- from 3 l
- Lifespan
- Annual
- Flowering
- Jun–Sep
- Hardiness
- Cold damage below 5 °C
- Water need
- Low
Photo: Laogooli · CC BY-SA 3.0 · Source
This description was machine-translated.
Description
Portulaca grandiflora is an annual succulent native to South America that tolerates heat and drought well. It grows flat and mat-like, reaching only 10 to 15 cm in height, and bears fleshy, cylindrical leaves on often reddish stems. From June to September it produces flowers in bright pink, red, orange, yellow, and white. In double-flowered varieties, the blooms resemble small roses. The flowers open only in sunshine and close in the afternoon or in overcast weather. Each bloom lasts only one day, but new buds continuously follow. In the garden, it is suited to hot, dry sites such as rock gardens, gravel beds, dry walls, paving joints, and containers and balcony boxes in full sun. It requires warmth and does not tolerate frost.
Care instructions
Give Portulaca grandiflora the hottest, sunniest spot available. A south-facing balcony or a gravel bed is ideal. Plant it out only after the Ice Saints, from calendar week 20 onward, when nights stay warm, as it suffers at temperatures below about 5 °C. The soil must be permeable and lean. Water sparingly, and only once the soil has dried out well. Waterlogging causes the fleshy stems to rot. The plant does not need fertilizer. In prolonged rain and cool weather the flowers stay closed, which is normal. Spent flowers do not need to be removed, as the plant reblooms on its own. Typical mistakes include a partly shaded site, too much water, and planting too early, when the plants stall during cold nights.
The care notes were machine-translated from German.
Garden year
SowingMar–May
FloweringJun–Sep
Germination
- Soil temperature
- from 18 °C, ideally 24 °C
- Days to sprout
- 7 to 14 days
- Light
- Needs light to sprout
- Sowing depth
- Press in, don't cover
- How to start
- Start indoors, then plant out
Soil & site
Soil pH
Soil type
sandy, well-drained, lean, dry
The moss rose grows best in sandy, very free-draining, lean soil that warms up quickly in the sun. The pH can range from slightly acidic to neutral. In heavy, wet or nutrient-rich soil the fleshy shoots rot and the plant flowers poorly. On loamy soils, mix in plenty of sand or grit. In a container, use free-draining, lean compost and shallow pots with drainage holes.
Feeding
Light feeder
The moss rose needs no fertiliser. It flowers best on poor soils; nutrient-rich soil makes the shoots soft and the flowering sparse. In bowls and boxes, too, the fresh compost used at planting lasts the whole summer, so you do not need to feed.
Overwintering
The moss rose is an annual and dies with the first frost; even prolonged cool nights set it back. Clear it away in autumn. Overwintering is not worthwhile; in spring you raise new plants from seed. In warm sites it self-seeds, and seedlings appear in early summer. The tiny seeds ripen in small capsules; to collect them, cut them off on a dry day and let them dry further.
Propagation
Methods
- From seed
- Cuttings
Sow the moss rose indoors from March. The very fine seeds need light to germinate: mix them with a little fine sand, scatter them on the compost, press them down lightly and do not cover them. At 18 to 22 °C they germinate after one to two weeks. Prick out the seedlings into small pots and plant them out after the Ice Saints (mid-May). Direct sowing into the warm bed is possible from the end of May, but then it flowers later. Particularly attractive or double-flowered plants can be propagated in summer by cuttings: finger-length shoot pieces usually root quickly in loose soil.
For your garden
Grow Rose Moss yourself
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