How to grow moss rose (Portulaca grandiflora)

Portulaca grandiflora · rose moss, eleven o'clock, Mexican rose

Moss rose (Portulaca grandiflora) — a low, mat-forming succulent annual 8–20 cm tall with single or double flowers in red, orange, yellow, white and pastel shades. Moss rose grows best in full sun. Water it about every 7 days while it grows.

Updated: November 4, 2026

When to sow moss rose?

Sow for seedlings about 8 weeks before planting out.

Plant out in open ground about a week after your last spring frost, once the soil is warm.

It flowers about 80 days after the shoots appear and keeps flowering for about 120 days.

Frost dates · When to plant

Quick facts

Type	Flower
Latin name	Portulaca grandiflora
Family	Portulacaceae
Also called	rose moss, eleven o'clock, Mexican rose
Planted as	seed
How it is started	from seedlings or sown straight into the bed
Life span	grown for one season
Planting season	spring
Light	Full sun
Frost	does not tolerate frost
Soil for sowing	from 23 °C
Germination	4 days
Seedlings ready	52 days
First flowers	80 days after the shoots appear
Flowering lasts	120 days
Grown in	Open ground, At home

How long does moss rose take from sowing to flowering?

From sowing to the first flowers: about 84 days, or 12 weeks.

Step	Day
Sowing	0
Shoots appear	4
Seedlings ready to plant out	56
First flowers	84
End of flowering	204

Days count from the day of sowing or planting, by the figures of the card.

Moss rose care by growth stage

Open ground

Stage	Watering	Temperature	Feeding
Seedlings	every 3 days	—	—
Growth	every 7 days	—	—
Flowering	every 7 days	—	—

At home

Stage	Watering	Temperature	Feeding
Seedlings	every 3 days	—	—
Growth	every 4 days	—	—
Flowering	every 4 days	—	—

Growing notes

Light

Full sun; the flowers close at night and stay shut on cloudy or rainy days.

Soil

Well-drained sandy or rocky soil. It tolerates poor, dry soil and heat; poor drainage can cause crown rot.

Care

Sow on the surface without covering the seed, because it needs light, at 22–26 °C, 4–8 weeks before planting out, or sow in place once the soil has reached 23 °C. Seedlings do not take well to transplanting, so handle them carefully. Harden off and plant out after the last frost, 20–30 cm apart or three to a 25–30 cm container. Avoid overwatering. Deadheading is not required, though it keeps plants healthy and flowering well; it also stops self-seeding. Aphids and slugs may appear occasionally.

Plant lists it is in

What to grow on a windowsill or balcony

Part of: Garden flowers · Annual flowers from seed · Long-flowering plants · Flowers to sow straight into the bed

Sources

Figures checked against these sources.