Philadelphus spp., mock orange
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Deciduous Shrubs

Philadelphus spp.

mock orange

Hydrangeaceae

Species native to North America, Europe, and Asia. P. lewisii native to Pacific Northwest from British Columbia south to California. P. coronarius native to southeastern Europe and Asia Minor

At a Glance

TypeShrub
HabitUpright
FoliageDeciduous
Height4–10 feet (1.2–3 m)
Width4–8 feet (1.2–2.4 m)
Maturity4 years

Growing Zones

USDA Hardiness Zones

4 - 8
Zone 4
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
Attracts Butterflies
Drought Tolerant
Fragrant (strong)
Native to North America
Maintenancelow

Overview

A genus of approximately 60 species of deciduous shrubs in Hydrangeaceae, widely grown in Pacific Northwest gardens for their intensely fragrant white flowers in June. Most commonly grown species and hybrids reach 4–10 feet (1.2–3 m) tall and wide. Flowers four-petaled, cup-shaped, 1–2 inches (2.5–5 cm) across, white, borne in clusters at branch tips in June — sweetly fragrant with a scent resembling orange blossom, strongest on warm evenings. P. lewisii is the only Pacific Northwest native species, native to rocky slopes and streambanks from British Columbia to California, and is the state flower of Idaho. Commonly grown species include P. coronarius (sweet mock orange), P. x lemoinei (Lemoine mock orange), and P. x virginalis (Virginia mock orange). Bloom is brief — typically 2–3 weeks — but intensely fragrant. Hardy in USDA zones 4–8.

Native Range

Philadelphus species are native to North America, Europe, and Asia. P. lewisii is native to the Pacific Northwest from British Columbia south to California and east to Montana, growing on rocky slopes, forest edges, and streambanks. European and Asian species (P. coronarius, P. pubescens) and their hybrids (P. x lemoinei, P. x virginalis) are widely grown in cultivation.

Suggested Uses

Planted as a specimen shrub, informal hedge, or woodland garden accent at 5–8 foot (1.5–2.4 m) spacing. The intensely fragrant June bloom makes mock orange one of the most rewarding deciduous shrubs for Pacific Northwest gardens. Effective near seating areas, patios, and entryways where fragrance can be appreciated. P. lewisii is an excellent choice for native plant gardens and wildlife plantings.

How to Identify

Identified by opposite simple leaves with 3–5 veins from the base, 1.5–3 inches (4–7.5 cm) long; clusters of four-petaled white flowers 1–2 inches (2.5–5 cm) across at branch tips in June; and intensely sweet orange-blossom fragrance. Arching, multi-stemmed deciduous shrub with peeling bark on older stems. Distinguished from Deutzia by the four petals (vs. five) and stronger fragrance; from Exochorda by the smaller flowers in clusters (vs. larger flowers in racemes); from Spiraea by the four-petaled flowers and fragrance.

Appearance

Size & Dimensions

Height4' - 10'
Width/Spread4' - 8'

Reaches mature size in approximately 4 years

Colors

Flower Colors

white

Foliage Colors

green

Fall Foliage Colors

no change

Bloom Information

Bloom Period

~3 weeks
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Blooms in June, typically for 2–3 weeks. Flowers four-petaled, cup-shaped, 1–2 inches (2.5–5 cm) across, in clusters of 5–9 at branch tips. Intensely fragrant — one of the most powerfully scented shrubs in the Pacific Northwest garden. Fragrance strongest in warm weather and in the evening. Blooms on previous year's wood — prune only immediately after flowering to avoid removing next season's buds.

Detailed Descriptions

Flower Description

White, four-petaled, cup-shaped, 1–2 inches (2.5–5 cm) across; intensely fragrant with a sweet orange-blossom scent

Foliage Description

Opposite, simple, oval to lance-shaped with 3–5 veins from the base, 1.5–3 inches (4–7.5 cm) long; medium green; no significant fall color

Growing Conditions

Sun Requirements

Full Sun
Partial Shade
Requires 4-10 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
loamclaysand
Drainage
well drained

Water & Climate

Water Needs

Medium

Frost Tolerance

hardy

Time to Maturity

3–5 years

Drought Tolerance

Drought tolerant when established

Care & Maintenance

Care Guide

Plant in full sun to part shade in moist, well-drained soil. Space 5–8 feet (1.5–2.4 m) apart depending on species or cultivar size. Water regularly during establishment; moderately drought tolerant once established. Blooms on previous year's wood — do not prune in late summer, fall, or winter. Prune immediately after flowering to maintain size and encourage vigorous new flowering shoots.

Pruning

Prune immediately after flowering (late June–July) by cutting the oldest one-third of stems to the ground each year — this rejuvenates the shrub and maximizes flowering on young wood. Do not prune in fall, winter, or spring. Neglected overgrown specimens can be cut to within 12 inches (30 cm) of the ground in late winter to fully rejuvenate, sacrificing one season's bloom.

Pruning Schedule

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Maintenance Level

low

⚠️ Toxicity Warning

Non-toxic
Philadelphus spp. (mock orange) - Identification & Care Guide | PlantRef