Plants
Moss Rose
Portulaca grandiflora · Portulacaceae
Moss rose is the answer to the hottest spot on the house: a succulent summer flower with fleshy needle-like leaves that store water, and silky blooms in glowing candy colours. Where petunias and geraniums demand daily watering, it manages for days without. The flowers open only in sunshine — a small price for such mastery of drought.
- Light
- Full sun, the hotter the better — in shade the flowers stay closed.
- Watering
- Very little — the succulent leaves store water for days.
- Care level
- Easy
- Botanical
- Portulaca grandiflora
Botanically, moss rose is a close relative of edible purslane but is not a salad plant itself. The bred varieties — from series such as Sundial, Happy Hour or Mojave — offer double and single blooms from white through yellow and orange to strong magenta, often striped in several colours.
Its secret is the succulent foliage: like small water reservoirs, the leaves bridge dry spells that would wilt any other summer flower. That makes moss rose the classic choice for south-facing balconies, shallow bowls, rock gardens and graves in full sun — anywhere daily watering is impossible.
One quirk is worth knowing: the flowers open only in direct sun and close in overcast weather and in the evening. Newer breeds stay open longer, but in a shady spot or a rainy summer the show fails to appear — position matters more here than any care routine.
By far the most common mistake is over-provision: in rich, moist potting compost the fine roots rot and the plant grows fat instead of floriferous. Ideal is a lean, sandy, free-draining substrate and a watering rhythm that lets the soil dry out completely in between.
In design terms, moss rose looks best in shallow bowls and as a carpet along bed edges, where the low cushions display their colours across a wide area. We like to combine it with fellow drought artists such as echeveria, or with ornamental grasses that give the colour carpet structure.
Important for pet households: despite its harmless appearance, portulaca is toxic to cats and dogs, as the plant contains soluble oxalates. In households with nibbling animals it belongs in hanging baskets or raised spots.
Is Moss Rose toxic to children and pets?
- Children
- Mildly irritating
- Cats
- Toxic
- Dogs
- Toxic
Portulaca contains soluble oxalates and is considered toxic to cats and dogs; animals that eat larger amounts are especially at risk. For children, milder complaints are more likely — still plant it out of reach.
Typical symptoms: Drooling, vomiting, weakness and tremors; larger amounts can disturb calcium balance and lead to kidney problems.
In an emergency:call the German poison control centre in Bonn on +49 228 19240 (24/7) — for pets, contact an emergency vet directly. This information does not replace medical or veterinary advice.
Overview: toxic & non-toxic plants for cats, dogs and children
Care
- 01Choose the sunniest, hottest spot — without full sun the flowers will not open.
- 02Water very sparingly and let the soil dry out completely between waterings.
- 03Use a lean, sandy, free-draining substrate, not enriched all-purpose compost.
- 04Feed only every three to four weeks at low dose.
- 05Waterlogging is certain death — drainage holes and a drainage layer are essential.
- 06Plant out only after the last late frosts; it dislikes cold and wet in May.
Frequently asked
- Why are my moss rose flowers not opening?
- The flowers respond directly to sunlight: in overcast weather, rain or shady positions they stay closed. If the plant is in full sun and the blooms still stay shut, the soil is usually too wet or too rich.
- How often does moss rose need watering?
- Far less often than anything else in the box: in beds, rain is often enough once established; in bowls, watering about once a week suffices, every few days in high summer. The finger test decides — water only when the soil is completely dry.
- Is moss rose toxic to cats?
- Yes. Portulaca contains soluble oxalates that can cause drooling, vomiting and, in larger amounts, kidney problems in cats and dogs. In pet households plant it raised or in hanging baskets, and contact the vet if you suspect ingestion.
- Is moss rose suitable for grave planting?
- For graves in full sun it is actually one of the best summer plants: it copes for weeks without watering, stays low and flowers in strong colours. On shaded graves, however, it fails — the blooms stay closed there.