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Phlox divaricata 'Blue Moon' (Blue Moon Woodland Phlox)
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© Photo by David J. Stang, some rights reserved (CC-BY-SA) · Wikimedia Commons
Perennials

Phlox divaricata 'Blue Moon'

Blue Moon Woodland Phlox

Polemoniaceae
Garden selection; species native to eastern North America

At a Glance

TypePerennial
HabitSpreading
FoliageSemi-evergreen
Height10-15 inches (25-38 cm)
Width12-18 inches (30-45 cm)
Maturity2 years

Growing Zones

USDA Hardiness Zones

3 - 8
Zone 3Zone 4Zone 5Zone 6Zone 7Zone 8
These zones indicate the coldest temperatures this plant can typically survive.
What's my zone? →
Frost Tolerancehardy

Key Features

Attracts PollinatorsAttracts ButterfliesAttracts HummingbirdsFragrant (light)Container Friendly
Native to North America
Maintenancevery low

Overview

Phlox divaricata 'Blue Moon' is a woodland phlox selection with deeper blue color and rounder petals than the standard species, growing 10–15 inches (25–38 cm) tall and spreading by stolons. Deep blue to blue-violet five-petaled flowers 1.5 inches (4 cm) across have round, overlapping petals that create a fuller, more circular flower face than the notched or narrow petals of many P. divaricata forms. The deeper blue-violet color is more saturated than the typical pale lavender-blue of the species. The cultivar name 'Blue Moon' references both the color and the round petal shape. Blooms in April and May in the same woodland shade conditions as the species. The same stoloniferous spreading habit and semi-evergreen ground-cover behavior apply. Light sweet fragrance. Moist, humus-rich soil under deciduous trees. Not susceptible to powdery mildew. Deer may browse the foliage.

Native Range

The species Phlox divaricata is native to eastern North America. 'Blue Moon' is a garden selection for deeper blue color and round petal shape.

Suggested Uses

Used as a woodland ground cover where a deeper blue is desired than the standard species. The round-petaled flowers create a more polished look. Same woodland conditions as the species.

How to Identify

Identified by deep blue to blue-violet flowers with round, overlapping petals creating a fuller flower face on a low spreading woodland mat. The deeper blue and rounder petals distinguish 'Blue Moon' from the paler, narrower-petaled standard species.

Appearance

Size & Dimensions

Height10" - 1'3"
Width/Spread1' - 1'6"

Reaches mature size in approximately 2 years

Colors

Flower Colors

blue
violet

Foliage Colors

green

Fall Foliage Colors

semi evergreen

Bloom Information

Bloom Period

~4 weeks
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Spring
Flowering in April and May, approximately 4 weeks. Deep blue-violet flowers with round petals.

Detailed Descriptions

Flower Description

Deep blue to blue-violet, five-petaled with round overlapping petals

Foliage Description

Medium green, soft, lance-shaped

Growing Conditions

Sun Requirements

Partial ShadeFull 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 Range6.0 - 7.0(Neutral)
357912
Soil Types
loam
Drainagemoist

Water & Climate

Water Needs

Medium

Frost Tolerance

hardy

Time to Maturity

1-2 years

Care & Maintenance

Care Guide

Plant in partial to full shade under deciduous trees. Moist, humus-rich soil. Mulch with leaf mold. Shear lightly after bloom.

Pruning

Shear lightly after bloom to tidy the mat.

Pruning Schedule

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summer

Maintenance Level

very low

Container Growing

✓ Suitable for container growing

Minimum container size: 3 gallons

⚠️ Toxicity Warning

Non-toxic