Is Oenothera Invasive? The Mexican evening primrose (Oenothera speciosa) is a naturalized non-native in California.Some may argue it’s an invasive, but I surmise that it’s not… yet. How to Kill Primrose. Do not plant. By this time it is too late to dig for the root. Some of the worst invasive plants are actually quite lovely, as you will see by viewing the photos on the following pages. Only in the spring of the second year does the flower stem shoot up. The pink Mexican Evening Primrose (Oenothera berlandieri) can become pretty invasive in a well-watered garden, but can be a great slope holder in the right circumstances. California has several native Oenothera species but O. speciosa is easy to identify. If you see pink evening primrose (the common name is stupid by the way—unlike the yellow evening primrose, this one's flowers open in morning and close at dusk) for sale at your garden center, I have a single word of advice. Evening Primrose is a biannual plant, which means in the first year it forms a rosette of leaves which lie close to the ground. Gerry Whitmont/Getty Images There are several very attractive flowers in the evening primrose genus. RUN. According to UC master gardener Anna Symkowick-Rose, the Mexican evening primrose is very difficult to eradicate. has yellow flowers that only open during the day.There is also an attractive pink version (Oenothera speciosa) known commonly as showy evening primrose, Mexican primrose, or Showy Ladies, which blooms in the—you guessed it—evening. Oenotheras can be aggressive and potentially invasive. It's purple partner (Osteospermum fruticosum - African Daisy) is another tough guy, but you wouldn't know it from the flowers. Sundrop (Oenothera biennis L.). Do not say to … Oenothera has made many contributions towards intergrating the ecology, evolution and genetics of species interactions. Rather than many of the native plants’ whites and yellows, this garden plant has delicate pink flowers. Do not buy. The Contributions of Oenothera to Biology. The name primrose might be attributed to plants from the genus Primula, or evening primroses, from the genus Oenothera. Some species, such as Oenothera Mexicana (Mexican Evening Primrose) are very invasive. The old adage of not being able to judge a book by its cover very much pertains to such barbarians.