What hardiness zones is Geranium 'Gerwat ROZANNE' suitable for?

Geranium 'Gerwat ROZANNE' is suitable for USDA hardiness zones 5, 6, 7, 8.

What are the sun requirements for Geranium 'Gerwat ROZANNE'?

Geranium 'Gerwat ROZANNE' requires Part Sun.

How much water does Geranium 'Gerwat ROZANNE' need?

Geranium 'Gerwat ROZANNE' has Low water needs.

Geranium 'Gerwat ROZANNE', Rozanne geranium

1 / 9

Perennials

Geranium 'Gerwat ROZANNE'

Rozanne geranium

Geraniaceae

Hybrid of garden origin; parent species from central and western Asia

At a Glance

TypePerennial

HabitMounding

FoliageDeciduous

Height18–20 inches (45–50 cm)

Width24–36 inches (60–90 cm)

Maturity2 years

Growing Zones

USDA Hardiness Zones

5 - 8

Zone 5

Zone 6

Zone 7

Zone 8

These zones indicate the coldest temperatures this plant can typically survive.

Frost Tolerancehardy

Key Features

Attracts Pollinators

Deer Resistant

Drought Tolerant

Fragrant (light)

Container Friendly

Maintenancelow

Overview

A mounding to sprawling perennial reaching 18–20 inches (45–50 cm) tall and 24–36 inches (60–90 cm) wide. Rozanne is a sterile hybrid hardy geranium producing violet-blue saucer-shaped flowers 1.5–2 inches (4–5 cm) across with white centers and dark blue-violet veining radiating from the center. Petals five, slightly notched. Leaves deeply 5–7 lobed, palmate, 3–5 inches (7.5–13 cm) across, mid-green, aromatic when bruised; leaves develop reddish-orange tints in fall. Blooms from late spring continuously through fall without deadheading — one of the longest bloom periods of any hardy geranium. Being sterile, it produces no viable seed and redirects energy entirely to flower production. Hardy in USDA zones 5–8. Received the RHS Award of Garden Merit and was named Perennial Plant of the Year in 2008.

Native Range

Rozanne is a hybrid geranium of garden origin, developed in the United Kingdom in the late 1980s. It does not have a native range; parent species are from central and western Asia. The genus Geranium is distributed widely in temperate regions worldwide.

Suggested Uses

Used as a long-season ground cover in sunny to partly shaded borders at 24–36 inch (60–90 cm) spacing. Trailing stems fill gaps between shrubs and taller perennials. Suitable for containers of 5+ gallons (19+ L). Combines well with upright companions such as salvia, agastache, and ornamental grasses that contrast with its sprawling habit.

How to Identify

Identified by deeply lobed palmate leaves 3–5 inches (7.5–13 cm) across that are aromatic when bruised, and saucer-shaped violet-blue flowers 1.5–2 inches (4–5 cm) across with a white center and dark blue veining. Distinguished from Geranium himalayense and G. magnificum by much longer bloom season, sprawling spreading habit, and sterility (no seedheads form). Leaves develop reddish-orange fall color.

Appearance

Size & Dimensions

Height1'6" - 1'8"

Width/Spread2' - 3'

Reaches mature size in approximately 2 years

Colors

Flower Colors

blue

violet

white

Foliage Colors

green

Fall Foliage Colors

orange

red

Bloom Information

Bloom Period

~22 weeks

SpringSummerFall

Blooms from late May through October — typically 5–6 months of continuous flowering. Unlike many hardy geraniums that bloom only once in early summer, Rozanne maintains near-continuous bloom without deadheading. Peak flowering June through August; bloom slows in the hottest weeks in zones 7–8 then resumes in September.

Detailed Descriptions

Flower Description

Violet-blue with white center and dark blue veining

Foliage Description

Mid-green, deeply 5–7 lobed, palmate; reddish-orange fall tints

Growing Conditions

Sun Requirements

Full Sun

Partial Shade

Requires 4-8 hours of direct sunlight daily

• Full Sun: 6+ hours of direct sunlight

• Partial Shade: 3-6 hours of direct sunlight

• Full Shade: Less than 3 hours of direct sunlight

Soil Requirements

pH Range6.0 - 7.5(Neutral)

357912

Soil Types

loamsandclay

Drainage

well drained

Water & Climate

Water Needs

Low

Frost Tolerance

hardy

Time to Maturity

2–3 years

Drought Tolerance

Drought tolerant when established

Care & Maintenance

Care Guide

Plant in full sun to part shade in average, well-drained soil. Performs well in full sun in zones 5–6; benefits from light afternoon shade in zones 7–8. Space plants 24–36 inches (60–90 cm) apart. Water during establishment; once established, tolerates dry periods of 1–2 weeks. Cut back by one-half in midsummer (late June to early July) if plants become leggy — this stimulates fresh foliage and a second flush of bloom within 2–3 weeks. Apply a light layer of compost in early spring. Divide every 3–5 years in early spring if plants become overly large. No serious pest or disease problems; vine weevil may feed on roots in containers.

Pruning

Cut back by one-half in late June to early July when plants become leggy after the first flush; new growth and flower buds emerge within 2–3 weeks. Cut to 3–4 inches (7.5–10 cm) in late fall after frost kills the foliage. Do not deadhead — Rozanne is sterile and continuous flowering does not require deadheading.

Pruning Schedule

summerfall

Maintenance Level

low

Container Growing

✓ Suitable for container growing

Minimum container size: 5 gallons

⚠️ Toxicity Warning

Non-toxic