Cold hardiness

Future

2050

2100

These values are location-based: this location's current hardiness is the baseline, and the 2050 value is a projected future climate for this same location.

Now

Zone 6b

USDA

Published baseline for this location from 1991-2020.

Source: USDA Plant Hardiness Zone Map 2023 (1991-2020 climatology) via ArcGIS FeatureServer

Well-suited

2050

Zone 7a

Plotwright

Projected zone for this same location in 2050 (2041-2070) using SSP3-7.0 (regional rivalry).

Well-suited

In plain terms: This location is in Zone 6b today. Its hardiness profile is cold winters, and coldest nights are typically around -3°F. By 2050, the projected hardiness zone is Zone 7a based on SSP3-7.0 (regional rivalry). That is a +0.5-zone shift from Zone 6b to Zone 7a by 2050.

✓

Well-suited today and still thriving in 2050.

Heat tolerance

Future

2050

2100

Heat tolerance values are location-based too: heat days today are observed at this site, and the 2050 value projects this same location under a future climate.

Loading AHS heat-zone data for this location...

Where this plant fits

Suitable across 45 ecoregions — 45 climate-resilient through 2070. Best matches first.

Appalachian mixed mesophytic forests

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Appalachian-Blue Ridge forests

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Arizona Mountains forests

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Atlantic coastal pine barrens

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Blue Mountains forests

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California coastal sage and chaparral

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Canadian Aspen forests and parklands

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Central Pacific Northwest coastal forests

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Central Tallgrass prairie

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Central-Southern Cascades Forests

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What it needs

Conditions

Light

Full sun

Water

Low water

Spacing

8"

Habit

Low, prostrate to slightly ascending succulent annual forming a moss-like mat

Care tips

•

Give it the hottest, sunniest, best-drained spot you have — it shrugs off drought and poor soil.

•

Hold back on water and fertilizer; rich, wet ground brings crown rot and fewer flowers.

•

Expect the show to pause on gray days — the flowers only open in bright sun.

Lifecycle

Planting

Direct sow after the last frost once the soil has warmed, or start indoors 6-8 weeks earlier (Missouri Botanical Garden PlantFinder). Plant in poor to average, dry to moderately moist, well-drained soil in full sun; sharp drainage matters more than fertility.

Transplanting

Set out young plants after frost danger passes, spacing them so the mats knit together; the fleshy stems root easily where they touch soil.

Early growth

Water lightly until seedlings establish, then let the soil dry between waterings — the plant is drought tolerant and resents wet feet.

Maturity

Forms a low mat 3-9 inches tall and 6-12 inches wide, blooming June to frost. Flowers open in sun and close on cloudy or rainy days; deadheading is optional since the plant blooms continuously and self-sows.

Propagation

Grows readily from seed and self-sows in open ground; stem cuttings root quickly in warm weather. Missouri Botanical Garden PlantFinder notes no serious pest or disease problems, though aphids and crown rot in poorly drained soils can occur.

Pollination

Self-fertile

The sun-opening flowers are pollinated by small bees and also self-pollinate as they close, setting abundant seed; no separate pollinizer plant is required. Bloom depends on sunshine — flowers stay shut on cloudy or rainy days.

Plants don't grow alone

Pollen forage

Bee

Sweat bees (Lasioglossum spp.)

Small sweat bees such as Lasioglossum work the pollen-rich open flowers on sunny days, when the blooms are receptive.

For people

Edibility undocumented

Grown as an ornamental; Missouri Botanical Garden PlantFinder does not list any culinary use. Note that the edible "purslane" of cooking is the related species Portulaca oleracea, not this showy-flowered moss rose.

Climate notes

•

Missouri Botanical Garden PlantFinder lists Portulaca grandiflora for USDA zones 2 to 11 (grown as a warm-season annual), 0.25-0.75 ft tall by 0.5-1 ft wide, blooming June to frost in full sun with dry-to-medium moisture and good drainage.

•

Native to Brazil, Argentina, and Uruguay and grown across North America as a heat- and drought-tolerant bedding annual; Missouri Botanical Garden PlantFinder lists it as tolerant of drought and dry soil and useful in poor dry soils where many other plants struggle.

•

Missouri Botanical Garden PlantFinder reports no serious insect or disease problems, with aphids and crown rot in poorly drained soils the main things to watch.

In the designer

Growth over time

1-3" tall · 2-5" spread

Seedling stage 2-3 weeks after direct sowing or transplanting; fleshy cylindrical leaves and reddish branching stems begin.

Design roles: Border · Filler · Container

Moss rose

At a glance

Related products

Why it matters

Cold hardiness

Heat tolerance

Where this plant fits

What it needs

Lifecycle

Pollination

Plants don't grow alone

For people

Climate notes

In the designer

Sources & citations