Oenothera speciosa aka White Evening Primrose

Oenothera speciosa belongs to the evening primrose family. It spreads and lives for more than one year. Gardeners call it pink ladies or Mexican evening primrose. It is native to central and east-central parts of the USA. Its range reaches south into northern and central Mexico. The plant has spread beyond this range across the USA. It loses its leaves each year and covers the ground.

Garden plants reach about 1 foot (0.3 m) tall. RHS lists a top height and spread of 1.6 feet (0.5 m). Creeping rhizomes, or stems below ground, help patches spread. Seeds also help them grow beyond the first planting site. The pale green stems have fine hairs and are round in cross-section. They may stand upright, arch, or trail across the ground. Green, lance-shaped leaves form rosettes, or rings, near the base. Leaves grow in turn along the stems, not in pairs. They may have short stalks. Their edges can be wavy, toothed, or deeply lobed.

Each flower has four petals with colored veins. The centers are yellow. White blooms turn pink as they age. Their cup or shallow bowl shape makes them stand out. The largest flowers reach about 0.26 feet (0.08 m) across. Missouri Botanical Garden lists blooms from May through July. RHS reports blooms from early summer into early autumn. Flowers may open by day or evening, depending on location. Bees and butterflies visit them for nectar. Small, oval seed capsules have four angles and hold many seeds. Birds and small mammals feed on the seeds.

Full sun gives the best flower display. In shade, plants can cover the ground but may not bloom. Poor soil or soil with modest fertility suits this plant. It grows in several soil types, but water must drain well. Acid, neutral, and alkaline soils can all suit it. It copes with drought and dry to fairly moist soil. Without summer moisture, it may enter a resting state. Missouri Botanical Garden gives USDA zones 4–9. RHS rates it H5. The plant needs no routine pruning. Gardeners can grow it from seeds or divide plants. They can also use softwood cuttings.

Meadows and wildflower gardens let it spread without crowding nearby plants. It also suits slopes, gravel gardens, and informal plantings. In beds, its growth can overwhelm nearby plants. Poor, rocky soil can help limit this spread. Serious pest and disease problems are rare. Slugs and aphids may occur. Leaf spot, powdery mildew, and downy mildew are possible. Rich, wet, heavy soil raises the risk of root rot. Leaves can serve as cooked greens or salad leaves. They taste best when picked before the plant blooms. The evidence does not show whether it is safe for pets. Nor does it show whether other plant parts are safe.