Cut leaf evening primrose (Oenothera laciniata) is a native, biannual plant. It forms a rosette during its first year of growth and produces yellow flowers on low spreading stems in its second year. The pretty, yellow flowers open in the evening and close during bright, sunny conditions Flowering will last for over a month, and sphinx moths and native bees pollinate the flowers. Unfortunately, the plant also hosts the tarnished plant bug, a piercing, sucking insect that feeds on vegetable and ornamental herbaceous plants.
Cut leaf primrose in thin, open lawn.
Jackie Jordan, ©2023, Clemson Extension
Cut leaf evening primrose grows in open, disturbed sites and tolerates dry conditions. It is mainly found in areas with sandy to loamy, sandy soils. Cut leaf evening primrose can be removed by hand but be careful; this weed develops a thick tap root that can be difficult to remove. Herbicides can control cut leaf evening primrose, but control is difficult once plants mature and begin producing flowers.
Cut leaf primrose flower.
Jackie Jordan, ©2023, Clemson Extension
Cut leaf primrose plant.
Jackie Jordan, ©2023, Clemson Extension
To limit the spread of this weed in your landscape, use a 3-inch layer of medium to coarse bark mulch in flower beds and employ cultural practices that encourage a thick stand of turfgrass. Proper mowing techniques like mowing at the correct height and only removing one-third of the blade height at a time will encourage a dense stand of grass. To find your proper mowing height, please see HGIC 1205, Mowing Lawns.
Research has shown that germination rates increase with lower soil pH, so if cut leaf evening primrose is prolific in your landscape, a soil sample can help determine what amendments your soil might need. Please see HGIC 1652, Soil Testing, for more information on how to take a proper soil sample.
Herbicide recommendations will vary based on site conditions. For personal guidance, please contact HGIC at hgic@clemson.edu or 1-888-656-9988.
