Each sundrop blossom lasts only a day but the plant continually produces new blooms for several weeks in late spring and early summer.
Sundrops is an herbaceous perennial that is a common wild flower in eastern North America. It is characterized by branched, softly hairy stems that are tinged with red, clear yellow flowers with orange stamens that open during the day, and mid-green hairy leaves that turn dull red after the first frost. The lance shaped to oval stem leaves are toothed on their edges and are 1-4 in (2.5-10 cm) long. The basal leaves are a little more ovate. The flowers are cup shaped, have four petals at the end of a slender tube, orange stamens and a conspicuous 4-branched stigma that forms a cross. They are borne in racemes of 3-10 at the tips of the branches. An individual flower is about 1-2 in (2.5-5 cm) across. Each flower opens in the morning and fades by midday, but the show continues for several weeks in spring and summer. With its erect, branching habit, a sundrops plant is usually around 1-3 ft (30-90 cm) tall with a spread of about a foot or two (30-60 cm). 'Fireworks' (aka 'Fyrverkeri') has red flower buds that open to yellow flowers and leaves decorated with purple-brown splotches.
The naturally occurring subspecies Oenothera fruticosa subsp. glauca (formerly known as O. tetragona) has larger leaves that are tinted with red and paler yellow flowers. Most of the available garden cultivars probably are from this subspecies. Selections include 'Lady Brookborough' with smaller, but especially numerous flowers; 'Sonnenwende' whose leaves turn bright red in summer while producing a profusion of rich yellow flowers from early summer until first frost; 'Youngii' which grows in a spreading mat less than 18 in (45 cm) high; 'Highlights' that never gets more than a foot (30 cm) tall and has flowers 2 in (5 cm) wide; and 'Yellow River' with red stems and larger flowers to 2.5 in (6.3 cm) across.
Sundrops, Oenothera fruticosa, grows in dry to wet, often rocky, fields, meadows, open woods and roadsides in eastern North America from Minnesota and Nova Scotia, south to northern Florida and eastern Oklahoma. It's usually found in sandy, sunny sites.
Although sundrops tolerates poor soils, it does better when the soil is supplemented with organic material, and does best in acidic soils. Light: Sundrops will grow in sun to partial shade, but flowers best in the more sunny spots. Moisture: The easy-to-grow sundrops tolerates wet or dry soils, and can withstand natural dry periods. Hardiness: USDA Zones 4-8. Propagation: Sow seeds in autumn. Sundrops spreads with runners and stolons and can be propagated by dividing the stoloniferous roots and also by starting soft, fast growing stem tip cuttings in spring.
Saint Francis watches over a spring time patch sundrops in full bloom.
Sundrops is grown in herbaceous flower beds, borders, and as edging, and it can be used in rock gardens. This is a pretty perennial with clear yellow flowers held well above dark green foliage. Once a popular pass-along in old fashioned gardens, sundrops is enjoying a renaissance, what with the growing popularity of native plants and wildflowers. This is a carefree, low maintenance flower that will grow in almost any soil, even acidic, poor, rocky, sandy or clayey soils. Sundrops dies to the ground in winter, but comes back in spring and ultimately grows into a showy full-flowered bushy clump. Although it can spread by its runners, it is not particularly aggressive and usually is well behaved, staying in a manageable open and airy two-foot (60 cm) bush.
Hummingbirds are attracted to the flowers. It is reported that the Cherokees ate the leaves as a pot herb after boiling in one rinse of water and cooking in hot grease. Seeds from the closely related evening primrose (Oenothera biennis) have been shown to contain the essential fatty acid gamma-linolenic acid, believed to be useful in lowering blood pressure, and treating a variety of ailments.
Features Oenothera fruticosa is listed a Species of Special Concern in Connecticut. Oenothera fruticosa subsp. glauca was formerly called Oenothera tetragona, and still is in much of the horticultural literature.
Of the 125 or so species of evening primroses, about a half dozen are popular garden flowers. Many of the others are nuisance weeds. Pink evening primrose (O. speciosa) is a well known garden flower that also is native to the eastern U.S.
It's easy to recognize members of the evening primrose family, Onagraceae: They have four persistent sepals that are conspicuously reflexed downward at the base of the flower or fruit capsule. No other family has sepals quite like that.