Oenothera macrocarpa
bigfruit evening primrose
Attracts PollinatorsAttracts ButterfliesDrought TolerantFragrant (light)Container Friendly
Native to North America
Overview
Oenothera macrocarpa is a low, sprawling perennial in the evening primrose family, native to the central United States. It grows 6-12 inches (15-30 cm) tall and spreads 12-24 inches (30-60 cm) wide from a deep taproot, with reclining reddish stems and narrow, lance-shaped leaves 2-4 inches (5-10 cm) long that are often silvery-green. From late spring through summer it produces large, cup-shaped yellow flowers 3-4 inches (7.5-10 cm) across that open in the late afternoon or evening, are lightly fragrant, and last about a day. The flowers are followed by conspicuous winged seed capsules 1-2 inches (2.5-5 cm) long that give the plant its name. It grows on rocky prairies, limestone glades, and dry slopes, tolerating heat, drought, and poor alkaline soil once the taproot is established. Because of that taproot it transplants poorly after the first year and is slow to re-establish if moved. It rots in wet or heavy clay soils and is short-lived in rich, moist ground. The evening-opening flowers are visited by night-flying moths and by bees the following morning. Top growth dies back in winter, and the plant returns from the crown in spring. It is hardy to USDA zone 4.
Native Range
Oenothera macrocarpa is native to the central United States, from Nebraska and Missouri south through Kansas, Oklahoma, and Texas. It grows on rocky prairies, limestone glades, and dry, open slopes.Suggested Uses
Oenothera macrocarpa is used in rock gardens, dry borders, gravel gardens, and as a sprawling groundcover on sunny banks. It is spaced 18-24 inches (45-60 cm) apart to allow its trailing stems room. It also grows in containers with sharp drainage.How to Identify
Appearance
Size & Dimensions
Height6" - 1'
Width/Spread1' - 2'
Reaches mature size in approximately 3 years
Bloom Information
Detailed Descriptions
Foliage Description
Green to silvery greenGrowing Conditions
Sun Requirements
Requires 6-12 hours of direct sunlight daily
• Full Sun: 6+ hours of direct sunlight
• Partial Shade: 3-6 hours of direct sunlight
• Full Shade: Less than 3 hours of direct sunlight
Care & Maintenance
Care Guide
Oenothera macrocarpa grows in full sun in well-drained rocky, sandy, or loamy soil with a pH from about 6.0 to 8.0. Once established its deep taproot carries it through heat and drought, and it needs little supplemental water. It rots in wet or heavy clay and is short-lived in rich, moist ground. No fertilizer is needed in lean soils. The taproot makes established plants hard to move, so a permanent position chosen from the start gives steadier results. It is hardy to USDA zone 4 and dies back to the crown each winter.Pruning
Oenothera macrocarpa needs little pruning. Spent flowers and developing seedpods can be removed to extend bloom and limit self-sowing, or left for their winged capsules. Dead top growth can be cut back in late winter before new shoots appear.Container Growing
✓ Suitable for container growing
Minimum container size: 2 gallons