What is Garden Evening Primrose?

Garden Evening Primrose

It is a cultivar of uncertain origin. The Jepson Manual of Higher Plants in California suggests it is "possibly derived in Europe from hybrids between two North American species."

On beaches and coastal bluffs.
Clam Beach in McKinleyville has many plants.
There are a few plants alongside U.S. Highway 101 near park property on the south side of the Klamath River at the Coastal Drive exit.

It cross pollinates with Wolf's evening primrose (Oenothera wolfii), a native, sensitive (CNPS List 1B) plant species. Cross pollination contaminates the gene pool of the Wolf's evening primrose, swamping out its native characteristics.
The wild hybrid (Oenothera glazioviana x wolfii) seems to be more aggressive than either parent.

Populations of the native, Wolf's evening primrose, are monitored annually in the parks.
If hybrids are found, they are removed immediately.
The parks cooperate with adjoining private landowners and the California Department of Transporation to remove any plants which may jeopardize the genetic integrity of the Wolf's evening primrose within the parks.
Plant nurseries, landowners and landscapers are made aware of the problem of planting garden hybrid evening primrose near beaches and coastal bluffs in the vicinity of Wolf's evening primrose populations.

Spread the word that garden evening primrose can genetically threaten unique native plant species. Discourage people from planting it anywhere near beaches and coastal bluffs.
Do not attempt to remove any plants you see by yourself! The garden hybrid and the threatened native tend to occur in similar coastal habitats. It takes a trained botanist, familiar with both, to distinguish between them.
To learn more and to get more involved in control of harmful exotics, sign up as a Volunteer in Parks (VIP).