Opening in the evening, the flowers of the pink evening primrose start out white and then age to pink.
In contrast to its predominantly yellow flowered brethren, this evening primrose produces white flowers that turn rosy pink from the outer edge of the petals inwards as they age. The plants grow 8-24 in (20.3-61 cm) high and spread up to 15 in (38.1 cm), sending runners out beyond that. The tough, slender, reclining stems support narrow spoon shaped leaves. The leaves tend to have deeply cut margins, especially near the base of the plant, where they are larger. The bowl-shaped flowers face skyward. They appear in mid-late spring and are nearly 2 in (12.7 cm) across. Starting out as nodding buds, flowers emerge from long tubes in the upper leaf axils. The huge stamens at the center of the flower are bright yellow. There may also be a yellowish tinge to the base of the petals and/or a reddish tinge to their veins. The blooms unfurl in the evening and remain open through the morning - all day when it is overcast. The seeds that follow in early summer are borne in ovalish winged 0.5 in (1.3 cm) capsules. 'Pink Petticoats' has an especially nice scent in the evenings. 'Woodside White' is a low-growing plant that produces white flowers with greenish centers. 'Rosea' has pink flowers.
Pink evening primrose comes from the south-central United States. It is native to the rocky prairies and savannas of the lower Midwest, but now commonly seen along roadsides and in disturbed areas over a much broader region.
Pink evening primrose will grow nicely in poor soil. Plants are late to emerge in the spring, so their locations should be marked. They may not be just where you planted them though! Evening primroses tend to be surreptitiously invasive. They send their roots far and wide during the winter when no top growth is visible, then pop up everywhere in the spring.
Light: Full sun. Moisture: Plants are likely to die of root rot if the soil is not well drained. They do fine in high humidity. Hardiness: USDA Zones 5 - 9. Propagation: Pink evening primroses are easy to grow from seed. Sow them outdoors late summer to fall or in early spring or sow indoors in early spring. The seeds can simply be scattered outdoors where they are to grow if the ground is not too hard or densely vegetated. Indoors, keep the planting medium moist and at a temperature between 68ºF (20ºC) and 86ºF (30ºC). Seedlings should appear in 2-3 weeks. Pink evening primrose also can be propagated vegetatively by dividing the root clumps in spring
Evening primrose grows in low mounds that are perfect for edging woodland trails or even suburban streets.
Evening primroses are useful in a wide variety of semi-wild garden settings: in rock gardens, wildflower meadows, and naturalistic borders and along the edges of roads and trails. These flowers are best planted where you don't mind them spreading around a bit.
Pink evening primrose is a wonderful wildflower for roadside beautification! It will readily form showy colonies on rocky highway rights of way and gravelly driveway edges. The flowers also attract bees, moths, and hummingbirds.
Pink evening primrose can be an invasive species. Given a rich, moist site, it can turn into an aggressive weed!