Oenothera Species, Common Evening Primrose, Hoary Evening Primrose, Night Willow-Herb

Oenothera biennis

Family: Onagraceae (on-uh-GRAY-see-ee) (Info)
Genus: Oenothera (ee-no-THEE-ruh) (Info)
Species: biennis (by-EN-iss) (Info)



Water Requirements:

Drought-tolerant; suitable for xeriscaping

Average Water Needs; Water regularly; do not overwater

Sun Exposure:

Full Sun




Foliage Color:

Unknown - Tell us


36-48 in. (90-120 cm)

4-6 ft. (1.2-1.8 m)

6-8 ft. (1.8-2.4 m)


6-9 in. (15-22 cm)

9-12 in. (22-30 cm)


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)

Where to Grow:

Unknown - Tell us



Bloom Color:

Bright Yellow

Bloom Characteristics:

Flowers are fragrant

Bloom Size:

Unknown - Tell us

Bloom Time:

Mid Summer

Late Summer/Early Fall

Other details:

May be a noxious weed or invasive

Soil pH requirements:

6.1 to 6.5 (mildly acidic)

6.6 to 7.5 (neutral)

7.6 to 7.8 (mildly alkaline)

Patent Information:


Propagation Methods:

From seed; sow indoors before last frost

From seed; direct sow after last frost

Seed Collecting:

Collect seedhead/pod when flowers fade; allow to dry

Properly cleaned, seed can be successfully stored


This plant is said to grow outdoors in the following regions:

Birmingham, Alabama

Blytheville, Arkansas

Morrilton, Arkansas

Amesti, California

Berkeley, California

Corralitos, California

Crescent City, California

Elkhorn, California

Interlaken, California

Merced, California

Pajaro, California

Watsonville, California

Trenton, Florida

Demorest, Georgia

Lewiston, Idaho

Champaign, Illinois

Glen Ellyn, Illinois

Albion, Indiana

East Chicago, Indiana

South Whitley, Indiana

Des Moines, Iowa

Prospect, Kentucky

Lisbon, Maine

Columbia, Maryland

Cumberland, Maryland

Millersville, Maryland

Oakland, Maryland

Valley Lee, Maryland

Amesbury, Massachusetts

Billerica, Massachusetts

Millbury, Massachusetts

Southborough, Massachusetts

Belleville, Michigan

Erie, Michigan

Owosso, Michigan

Pinconning, Michigan

Saint Helen, Michigan

Tawas City, Michigan

Isle, Minnesota

Minneapolis, Minnesota

Cole Camp, Missouri

Lanagan, Missouri

New Milford, New Jersey

Glen Cove, New York

Himrod, New York

Patchogue, New York

Schenectady, New York

Seaford, New York

Raleigh, North Carolina

Siler City, North Carolina

Glouster, Ohio

Hamilton, Ohio

Pleasantville, Ohio

Enid, Oklahoma

Pocola, Oklahoma

Newberg, Oregon(6 reports)

Lehigh Valley, Pennsylvania

Millersburg, Pennsylvania

Philadelphia, Pennsylvania

Washington, Pennsylvania

West Chester, Pennsylvania

Grenoble, Rhône-Alpes

, Saskatchewan

Mc Minnville, Tennessee

Arlington, Texas

De Leon, Texas

Fort Worth, Texas

Kaufman, Texas

Blacksburg, Virginia

Ellsworth, Wisconsin

show all

Gardeners' Notes:


On Jun 14, 2021, JennysGarden_TN from Collierville, TN wrote:

This plant is blooming in my zone 7b part shade garden. I bought the seeds as White Sundrop but was sold by a dishonest seller on Ebay.


On Feb 6, 2014, Rickwebb from Downingtown, PA wrote:

I know of this native plant as being a common wild plant of meadows and prairie in the Midwest and East USA and of the seashore of southern Delaware. It is often used in native prairie restorations. Good for pollinators. It is one of the American native forbs that has survived the change from native meadow to the mostly European-west Asian meadow that has taken over much of eastern North America after settlement with such dominant plants as Kentucky Bluegrass, Tall Fescue, Perennial Ryegrass, Queen Anne's Lace, Sweet-clover, Red Clover, Chickory, Common Yarrow, Mullein, and some others. A few other natives that have survived the change along with Common Evening-Primrose are: Goldenrods, Dogbanes, Common Milkweed, Fleabanes, Asters, and Pokeweed.


On Jul 9, 2012, WindheartCogs from Siler City, NC wrote:

This is a wonderful plant. Mine came out out a pack of wildflower seeds. It was hardly noticeable the first year, just a small rosette of leaves with a big white vein down the middle. The second year they got taller, and taller, and taller. Luckily they were at the back of my garden, or they would have obscured the whole thing. My only complaint would be that they did get VERY large, and eventually squished the California poppies under them. But by that time, the poppies were out of their prime, and the flowers were well worth it. Bright yellow, fabulously fragrant, numerous, and night blooming, they were just what I was looking for. And they bloom for months. I got to see some pretty neat moths feeding on them too. I had some Japanese beetles snacking on them, but they didn't ma... read more


On Jun 19, 2012, DrJill from East Washington, PA wrote:

Lovely, but verrrrrry tall plant. I put it at the base of my 6 foot chain link deer fence and it is almost that tall. It is contained between walkways [I suspect it could be invasive] but I am not having problems with it. The deer do not seem to like it - so I planted it at the edge of my garden. I enjoy having medicinal plants in my garden.


On Mar 31, 2011, fairygothmom from Glen Cove, NY (Zone 6b) wrote:

This sprung up in the lid of a covered-over well in my backyard. It was lovely with no care. I collected lots of seeds to use in butterfly garden seed bombs for brownfields.


On May 24, 2009, trioadastra from Woodbury, MN (Zone 4a) wrote:

I grew this plant as part of a wildflower mixture. It kept getting taller and taller, and looking more like a weed. Finally, at about 5 ft tall, it began to bloom. The flowers themselves are nice, but the size of the plant overwhelms them and leaves much to be desired. Mine did not reseed, and I don't consider it much of a loss.


On Jan 17, 2005, JodyC from Palmyra, IL (Zone 5b) wrote:

Moths pollinate the flowers, particularly Sphinx moths. Other occasional visitors include the Ruby-Throated Hummingbird, honeybees, bumblebees, and Anthedonia compta (Primrose Miner Bee), the latter being an oligolege. These insects seek nectar, although some of the bees collect pollen. The caterpillars of several moths feed on the foliage. This includes Endryas unio (Pearly Wood Nymph), Desmia funeralis (Grape Leaffolder Moth), Hyles lineata (White-Lined Sphinx), and Mompha eloisella (Momphid Moth; bores through stems). Various beetles feed on the foliage, including Popillia japonica (Japanese Beetle), Grahops pubescens (Leaf Beetle sp.), Altica fusconenea (Flea Beetle sp.), and several Curculio beetles. The seeds are eaten by goldfinches.


On Sep 21, 2004, nevrest from Broadview, SK (Zone 3a) wrote:

Grows here in Zone 3. Self-seeds abundantly here in Zone 3. I have a garden filled with them started from one single plant. I would rate it as quite invasive.


On Sep 20, 2004, txbabycat from Flower Mound, TX wrote:

I purchased a pack of mixed wild flowers and some of these came up last year. During the winter here in Texas, which is mild, but it does get cold, the green leaves part of the plant stayed alive all winter long being low to the ground. WIth the onset of spring this year they shot up to about 3-4 feet tall and produced a lot of flowers all summer. They were under a shade tree and received partial shade and some sun. You do have to watch for the aphids, they seem to love this plant. You can contol them with a soapy water mixture sprayed on the plant.


On Sep 3, 2004, WillowWasp from Jones Creek, TX (Zone 9a) wrote:

This plant grows in the Dunes at the beach. It seems to do very well there and is doing a part in keeping the sand from blowing where it's pretty thick. It dosen't seem to be effected by the salt water or spray. Some of it is pretty close to the surf and it has been growing there for quite some time and it is flowering and sending out more runners..


On Aug 16, 2004, cherishlife from Pocola, OK (Zone 7a) wrote:

Evening primrose is a biennial plant with numerous, crinkled, lance-shaped leaves and green stems with red splotches. The flowers on this plant were found blooming on a cloudy day, but commonly only bloom early morning or evening. Flowers are bright yellow, fragrant with four broad petals. This plant was found growing alongside a country road and stands about 7 feet tall. Flowers are produced all along the stalk and bloom is continuous from June through autumn.

Evening primrose was used by the North American Indians for a variety of medical problems. This plant is grown commercially for its seed oil which is rich in GLA (gamma linoleic acid) fatty acids; cis-linoleic (70%), cis-gammalinolenic acid (9%).

Above ground parts are thought to have astringent prop... read more