What hardiness zones is Osmunda regalis 'Purpurascens' suitable for?

Osmunda regalis 'Purpurascens' is suitable for USDA hardiness zones 3, 4, 5, 6, 7, 8, 9.

What are the sun requirements for Osmunda regalis 'Purpurascens'?

Osmunda regalis 'Purpurascens' requires Part Shade.

How much water does Osmunda regalis 'Purpurascens' need?

Osmunda regalis 'Purpurascens' has High water needs.

Osmunda regalis 'Purpurascens' (Purple Royal Fern)

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Ferns

Osmunda regalis 'Purpurascens'

Purple Royal Fern

Osmundaceae

Near-cosmopolitan (Europe, Africa, Asia, Americas; temperate/subtropical wetlands)

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At a Glance

TypeFern

HabitUpright

FoliageDeciduous

Height3-5 feet (0.9-1.5 m)

Width2-4 feet (0.6-1.2 m)

Maturity5 years

Growing Zones

USDA Hardiness Zones

3 - 9

Zone 3 Zone 4 Zone 5 Zone 6 Zone 7 Zone 8 Zone 9

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

What's my zone? →

Frost Tolerancehardy

Key Features

Deer Resistant Container Friendly

Native to North America

Maintenancelow

Overview

Osmunda regalis 'Purpurascens' is a deciduous fern reaching 3-5 feet (0.9-1.5 m) tall with a spread of 2-4 feet (0.6-1.2 m) and a vase-shaped, upright habit. This cultivar of the royal fern is distinguished by strongly purple-tinted new growth: the spring croziers and young fronds emerge deep purple-bronze to wine-purple before maturing to green by midsummer. The fronds are bipinnately compound, 24-48 inches (60-120 cm) long, with broadly oblong pinnules 0.5-1 inch (1.3-2.5 cm) long. The stipes (stems) and rachis retain a purplish tint throughout the season. Fertile fronds produce brown, tassel-like sporangia clusters at the frond tips in summer. Growth rate is slow. Hardy to zone 3. Larger than 'Cristata' (which reaches 2-3 feet) and closer to the species in size. Requires consistently moist to wet, acidic conditions.

Native Range

Osmunda regalis is native to Europe, Africa, Asia, and the Americas in temperate and subtropical wetlands, bogs, and stream banks. 'Purpurascens' is a cultivar selected for purple new growth.

Suggested Uses

Planted at pond edges, stream banks, or in moist borders at 24-36 inch (60-90 cm) spacing. The purple spring growth is the distinguishing feature—site where emerging croziers are visible. Larger than 'Cristata'. Requires moist-to-wet acidic conditions. Not suitable for dry or alkaline sites.

How to Identify

Distinguished from 'Cristata' by the purple-tinted new growth (versus crested pinnae with normal coloring) and the larger size (3-5 feet versus 2-3 feet). Distinguished from 'Undulata' by the purple coloring (versus wavy pinnae margins). Distinguished from the species by the strongly purple-bronze spring coloring and the purplish-tinted stipes throughout the season. The large royal fern with deep purple-bronze spring croziers and purple-tinted stems is diagnostic.

Appearance

Size & Dimensions

Height3' - 5'

Width/Spread2' - 4'

Reaches mature size in approximately 5 years

Colors

Foliage Colors

green

purple

Fall Foliage Colors

gold

Bloom Information

Ferns do not flower. Fertile fronds produce brown tassel-like sporangia clusters at frond tips in June-August. Spores ripen and disperse by late summer.

Detailed Descriptions

Foliage Description

Spring: deep purple-bronze to wine-purple new growth; matures to green; purplish stipes/rachis year-round; bipinnate 24-48 inches

Growing Conditions

Sun Requirements

Partial Shade Full Shade

Requires 2-5 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 Range4.5 - 6.0(Acidic)

357912

Soil Types

peat loam silt

Drainagewet

Water & Climate

Water Needs

High

Frost Tolerance

hardy

Time to Maturity

3-5 years

Care & Maintenance

Care Guide

Plant in partial shade in consistently moist to wet, acidic soil (pH 4.5-6.0). Hardy to zone 3. Full shade reduces the purple coloring intensity. Thrives at pond edges and stream banks. Does not tolerate drought. Acidic, humus-rich soil required.

Pruning

Remove spent fronds in late autumn or early spring before new croziers emerge. No other pruning needed.

Pruning Schedule

early spring

Maintenance Level

low

Container Growing

✓ Suitable for container growing

Minimum container size: 7 gallons

⚠️ Toxicity Warning

Non-toxic