Bloomipedia
Blue phlox (Phlox divaricata)
Photo: cigazze via iNaturalist · CC BY 4.0 · resized

Flower profile

Blue phlox

Phlox divaricata

Blue phlox (Phlox divaricata) is a flowering plant in the Polemoniaceae family, native in the lower 48 states, blooming mostly March–May across the U.S.

Native in the lower 48

Blue phlox is a wildflower that USDA PLANTS lists as native in the lower 48 states. It's on our flower lists for 14 states, and across the U.S. it's most often seen in bloom in March–May.

33states where USDA records it
14Bloomipedia state lists include it
38,458U.S. sightings*

*iNaturalist research-grade observations, as of October 17, 2026.

On our lists for: Alabama, Illinois, Indiana, Iowa, Kansas, Kentucky, Maryland, Minnesota, Missouri, Nebraska, Ohio, Pennsylvania, Tennessee, West Virginia

Quick look

Phlox divaricata, the wild blue phlox, woodland phlox, or wild sweet william, is a species of flowering plant in the family Polemoniaceae, native to forests and fields in eastern North America.

  • It belongs to the Polemoniaceae family. iNaturalist
  • USDA PLANTS describes it as an herb (forb) with a perennial life cycle. USDA PLANTS
  • USDA PLANTS lists it as native in the lower 48 states and records it in 33 states. USDA PLANTS
  • In Ohio, most iNaturalist sightings of it in flower come in April–May. iNaturalist
  • In Illinois, most iNaturalist sightings of it in flower come in April–May. iNaturalist
  • USDA PLANTS lists its flower color as purple. USDA PLANTS
  • USDA PLANTS gives its bloom period as mid summer. USDA PLANTS
  • USDA PLANTS lists a mature height of about 3 ft. USDA PLANTS
  • iNaturalist has 6,255 research-grade sightings of it in Ohio, ranking #16 among the 186 flowers on our Ohio list. iNaturalist
  • iNaturalist has 5,712 research-grade sightings of it in Illinois, ranking #12 among the 180 flowers on our Illinois list. iNaturalist
  • iNaturalist has 2,813 research-grade sightings of it in Missouri, ranking #6 among the 177 flowers on our Missouri list. iNaturalist

When does it bloom?

Flowering records by month across the U.S. (iNaturalist research-grade observations marked “Flowering”) (5,153 records)
Bloom time in the 14 states whose Bloomipedia list includes it
StateTypePeak bloomSightings*
OhioNativeApril–May6,255
IllinoisNativeApril–May5,712
MissouriNativeMarch–May2,813
IndianaNativeApril–May2,747
TennesseeNativeMarch–April2,615
KentuckyNativeMarch–April2,542
PennsylvaniaNativeApril–May2,472
MinnesotaNativeApril–May1,637
MarylandNativeApril–May1,330
IowaNativeApril–May896
AlabamaNativeMarch–April884
KansasNativefew records (39)646
West VirginiaNativeApril575
NebraskaNativefew records (9)258

Conservation status

Federal (U.S. ESA)
Not listed No U.S. Endangered Species Act listing in the USFWS ECOS database. USFWS ECOS
NatureServe global
G5 Secure worldwide. NatureServe
State rare plant lists
Not listed Not on the official rare plant list in 10 of our 14 states.
See each state
Ohio
Not listed Not on Ohio endangered and threatened plants (Ohio Adm. Code 1501:18-1-03, eff. Dec. 26, 2024). NatureServe: SNR, not yet ranked in Ohio. OAC 1501:18-1-03
Illinois
Not listed Not on Illinois List of Endangered and Threatened Flora (17 Ill. Adm. Code 1050), per the Endangered Species Protection Board's 2025 checklist. NatureServe: SNR, not yet ranked in Illinois. IL E&T checklist 2025
Missouri
Not listed Not on Missouri Wildlife Code endangered species (3 CSR 10-4.111), plants. NatureServe: SNR, not yet ranked in Missouri. 3 CSR 10-4.111
Tennessee
Not listed Not on Tennessee endangered plants (Tenn. Comp. R. & Regs. 0400-06-02-.04, Rare Plant Protection and Conservation Act). NatureServe: SNR, not yet ranked in Tennessee. TN rule 0400-06-02-.04
Kentucky
Not listed Not on Kentucky endangered and threatened plant lists (400 KAR 3:040, eff. 2026). NatureServe: SNR, not yet ranked in Kentucky. 400 KAR 3:040
Pennsylvania
Not listed Not on Pennsylvania classified native plants (17 Pa. Code Ch. 45, Subchapter B, as amended 2023). NatureServe: S5, secure in Pennsylvania. 17 Pa. Code Ch. 45
Minnesota
Not listed Not on Minnesota endangered, threatened and special concern plants (Minn. R. 6134.0300). NatureServe: SNR, not yet ranked in Minnesota. Minn. R. 6134.0300
Maryland
Not listed Not on Maryland threatened and endangered plants (COMAR 08.03.08.05, .06 and .08). NatureServe: SNR, not yet ranked in Maryland. COMAR 08.03.08
Iowa
Not listed Not on Iowa endangered, threatened and special concern plants (Iowa Admin. Code r. 571-77.3). NatureServe: S4, apparently secure in Iowa. IAC 571-77.3
Nebraska
Not listed Not on Nebraska threatened and endangered species (163 Neb. Admin. Code ch. 4, § 004). NatureServe: SNR, not yet ranked in Nebraska. 163 NAC 4-004
Indiana
No list Indiana has no state law listing endangered or threatened plants (the DNR keeps a rare plant list, but it isn't regulatory), so we show NatureServe's Indiana ranks instead. NatureServe: S5, secure in Indiana.
Alabama
No list Alabama has no state law listing endangered or threatened plants, so we show NatureServe's Alabama ranks instead. NatureServe: SNR, not yet ranked in Alabama.
Kansas
No list Kansas's endangered and threatened list (K.A.R. 115-15-1) covers animals only, so we show NatureServe's Kansas ranks for plants. NatureServe: S5, secure in Kansas.
West Virginia
No list West Virginia has no state law listing endangered or threatened plants (only federally listed species are protected), so we show NatureServe's West Virginia ranks instead. NatureServe: S5, secure in West Virginia.
Rare elsewhere
Other states where NatureServe ranks it rare or missing: SD (SX). (S1 critically imperiled, S2 imperiled, SH possibly extirpated, SX presumed extirpated.)

Checked October 17, 2026. Rankings and lists can change, so follow the links for the latest.

Can you eat it?

For peopleNot well documented

None of the sources we checked (NC State Extension (no edibility or poison notes on its page), USDA PLANTS) say whether it's edible or poisonous for people. NC State Extension

For petsNot well documented

It isn't on the ASPCA plant list, and NC State Extension doesn't flag it for pets. For context only: ASPCA lists a related species, Phlox subulata (“Moss Phlox”), as non-toxic to dogs and cats. That doesn't tell us about this species, so keep pets away to be safe. ASPCA

🌿 Never eat a wild plant unless you're certain of its ID; this isn't medical advice. Worried about a person? Call Poison Control at 1-800-222-1222. Worried about a pet? Call your vet.

Where does it grow?

USDA PLANTS records blue phlox in 33 states plus Washington, D.C.

recorded by USDA PLANTS on our state lists not recorded

See the full list of states

Alabama, Arkansas, Connecticut, Delaware, Florida, Georgia, Illinois, Indiana, Iowa, Kansas, Kentucky, Louisiana, Maryland, Michigan, Minnesota, Mississippi, Missouri, Nebraska, New Jersey, New Mexico, New York, North Carolina, Ohio, Oklahoma, Pennsylvania, South Carolina, South Dakota, Tennessee, Texas, Vermont, Virginia, West Virginia, Wisconsin; District of Columbia.

Ohio counties with USDA records: Adams, Allen, Ashland, Ashtabula, Athens, Auglaize, Belmont, Brown, Butler, Carroll, Champaign, Clark, Clermont, Clinton, Columbiana, Coshocton, Crawford, Cuyahoga, Darke, Defiance, Delaware, Erie, Fairfield, Fayette, Franklin, Fulton, Gallia, Geauga, Greene, Guernsey, Hamilton, Hancock, Hardin, Harrison, Henry, Highland, Hocking, Holmes, Huron, Jackson, Jefferson, Knox, Lake, Lawrence, Licking, Logan, Lorain, Lucas, Madison, Mahoning, Marion, Medina, Meigs, Mercer, Miami, Monroe, Montgomery, Morgan, Morrow, Muskingum, Noble, Ottawa, Paulding, Perry, Pickaway, Pike, Portage, Preble, Putnam, Richland, Ross, Sandusky, Scioto, Seneca, Shelby, Stark, Summit, Trumbull, Tuscarawas, Union, Van Wert, Vinton, Warren, Washington, Wayne, Williams, Wood, Wyandot.

Illinois counties with USDA records: Adams, Alexander, Bond, Boone, Brown, Bureau, Calhoun, Carroll, Cass, Champaign, Christian, Clark, Clay, Clinton, Coles, Cook, Crawford, Cumberland, De Witt, DeKalb, Douglas, DuPage, Edgar, Edwards, Effingham, Fayette, Ford, Franklin, Fulton, Gallatin, Greene, Grundy, Hamilton, Hancock, Hardin, Henderson, Henry, Iroquois, Jackson, Jasper, Jefferson, Jersey, Jo Daviess, Johnson, Kane, Kankakee, Kendall, Knox, LaSalle, Lake, Lawrence, Lee, Livingston, Logan, Macon, Macoupin, Madison, Marion, Marshall, Mason, Massac, McDonough, McHenry, McLean, Mercer, Monroe, Montgomery, Morgan, Moultrie, Ogle, Peoria, Perry, Piatt, Pike, Pope, Pulaski, Putnam, Randolph, Richland, Rock Island, Saline, Sangamon, Schuyler, Scott, Shelby, St. Clair, Stark, Stephenson, Tazewell, Union, Vermilion, Wabash, Warren, Washington, Wayne, White, Will, Williamson, Winnebago, Woodford.

Missouri counties with USDA records: Adair, Andrew, Atchison, Audrain, Barry, Barton, Bates, Benton, Bollinger, Boone, Buchanan, Butler, Caldwell, Callaway, Camden, Cape Girardeau, Carroll, Carter, Cass, Cedar, Chariton, Christian, Clark, Clay, Clinton, Cole, Cooper, Crawford, Dade, Dallas, Daviess, DeKalb, Dent, Douglas, Dunklin, Franklin, Gasconade, Gentry, Greene, Grundy, Harrison, Henry, Hickory, Holt, Howard, Howell, Iron, Jackson, Jasper, Jefferson, Johnson, Knox, Laclede, Lafayette, Lawrence, Lewis, Lincoln, Linn, Livingston, Macon, Madison, Maries, Marion, McDonald, Mercer, Miller, Moniteau, Monroe, Montgomery, Morgan, Newton, Nodaway, Oregon, Osage, Ozark, Perry, Pettis, Phelps, Pike, Platte, Polk, Pulaski, Putnam, Ralls, Randolph, Ray, Reynolds, Ripley, Saline, Schuyler, Scotland, Scott, Shannon, Shelby, St. Charles, St. Clair, St. Francois, St. Louis, Ste. Genevieve, Stoddard, Stone, Sullivan, Taney, Texas, Vernon, Warren, Washington, Wayne, Webster, Worth, Wright.

Growing conditions

USDA PLANTS gives Blue phlox a medium shade tolerance, low drought tolerance and medium moisture use. It is rated for soil pH 5.5 to 7.2 and winter lows down to -33 °F.

Shade tolerance
Medium
Drought tolerance
Low
Moisture use
Medium
Soil textures it is adapted to
coarse, medium, fine
Soil pH range
5.5 to 7.2
Minimum temperature tolerated
-33 °F
Frost-free days needed (minimum)
100
Annual precipitation range
32 to 60 inches
Minimum root depth
14 inches
Salinity tolerance
None
Fertility requirement
Medium
Growth rate
Rapid
Lifespan
Long
Active growth period
Spring and Summer
Fruit or seed
Brown · Summer to Fall
Can be propagated by
container, sprigs
Commercial availability
Routinely Available

From the USDA PLANTS characteristics data for PHDI5. USDA ratings are general guidance for the species, not a guarantee for your garden.

Names, range and relatives

Native status by region (USDA PLANTS): Canada: Native; Lower 48 states: Native.

County records: USDA PLANTS lists it in 1098 counties across 28 states; the most are in Missouri (111), Kentucky (102), Illinois (100).

Other Phlox on Bloomipedia (7): Fall phlox, Prairie phlox, Longleaf phlox, Spiny phlox, Mountain phlox, Santa Fe phlox, Flowery phlox.

More from the Polemoniaceae family (14 on Bloomipedia; most observed first): Scarlet gilia, Jacob's ladder, Grand collomia, Narrow-leaf mountain trumpet, Sky pilot, Flaxflowered ipomopsis, Tall jacob's-ladder.

More Ohio flowers

Jacob's ladder (Polemonium reptans)

Jacob's ladder

Polemonium reptans

Native

🌼 Blooms in OH: April–May
Fall phlox (Phlox paniculata)

Fall phlox

Phlox paniculata

Native

🌼 Blooms in OH: July–October
Roses (genus Rosa) (Rosa)

Roses (genus Rosa)

Rosa

★ NY state flower🌷 Garden flower

🌼 Blooms in OH: May–July

Sources