Louisiana Blue Phlox, Woodland Phlox, Wild Sweet William, Wild Blue Phlox 'Blue Moon'

Phlox divaricata

Family: Polemoniaceae (po-le-moh-nee-AY-see-ee) (Info)
Genus: Phlox (floks) (Info)
Species: divaricata (dy-vair-ih-KAY-tuh) (Info)
Cultivar: Blue Moon
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Foliage Color:

Unknown - Tell us

Bloom Characteristics:

Flowers are fragrant

Water Requirements:

Average Water Needs; Water regularly; do not overwater

Where to Grow:

Unknown - Tell us


12-18 in. (30-45 cm)


12-15 in. (30-38 cm)


USDA Zone 3a: to -39.9 C (-40 F)

USDA Zone 3b: to -37.2 C (-35 F)

USDA Zone 4a: to -34.4 C (-30 F)

USDA Zone 4b: to -31.6 C (-25 F)

USDA Zone 5a: to -28.8 C (-20 F)

USDA Zone 5b: to -26.1 C (-15 F)

USDA Zone 6a: to -23.3 C (-10 F)

USDA Zone 6b: to -20.5 C (-5 F)

USDA Zone 7a: to -17.7 C (0 F)

USDA Zone 7b: to -14.9 C (5 F)

USDA Zone 8a: to -12.2 C (10 F)

USDA Zone 8b: to -9.4 C (15 F)

Sun Exposure:

Sun to Partial Shade

Light Shade


Unknown - Tell us

Bloom Color:

Medium Blue

Dark Blue

Bloom Time:

Mid Spring

Late Spring/Early Summer



Other details:

Unknown - Tell us

Soil pH requirements:

5.6 to 6.0 (acidic)

6.1 to 6.5 (mildly acidic)

6.6 to 7.5 (neutral)

Patent Information:

Unknown - Tell us

Propagation Methods:

By dividing rhizomes, tubers, corms or bulbs (including offsets)

From herbaceous stem cuttings

By simple layering

By serpentine layering

Seed Collecting:

Bag seedheads to capture ripening seed

Seed does not store well; sow as soon as possible


This plant has been said to grow in the following regions:

Cherry Valley, Illinois

Chicago, Illinois

Plainfield, Indiana

Hazard, Kentucky

Hopkins, Minnesota

Florence, Mississippi

Enid, Oklahoma

Christiana, Tennessee

Knoxville, Tennessee

Leesburg, Virginia

Pavillion, Wyoming

Riverton, Wyoming

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Gardeners' Notes:


On May 4, 2012, OldPerfessor from Hazard, KY (Zone 6b) wrote:

This is a great little plant to add to the flower garden. I have apprx. 6 of these that surround my flag pole and they have really exploded this Spring. They bloom here early and stay in bloom till the 1st of May. Also, they grow quite tall and should NOT be confused with Creeping Phlox. Average height is around 8" tall. They have a wonderful fragrance and a light blue bloom that is hard to beat.


On Feb 25, 2012, whitesam9 from Dayton, OH (Zone 5b) wrote:

I love this plant. The pictures don't always do it justice. The pictures sometimes make the flowers look lavender or pink, but they are really a beautiful shade of blue. It's one of the prettiest blues in my garden and has a fairly long blooming season for most of April and May.


On Oct 25, 2009, secygbo from Watertown, MA wrote:

This is one of my favorite plants. It has beautiful blue flowers in April and May which always get a lot of compliments. It is not a tall plant, growing about 6-8". It doesn't suffer from phlox mildew, so don't hesitate to get some. It even does well in shade or part shade.