Oxeye daisy, fleabane, evening primrose, and dame’s rocket have pretty flowers that can beguile us into inviting them into our gardens. Although birds and pollinators may appreciate them, they tend to spread rampantly, making us soon regret our invitation!
The plants
Oxeye daisies (Leucanthemum vulgare) are a perennial European species commonly found along roadsides, disturbed areas, and pastures. Oxeye daisies love moist clay soils and thrive in our region. Plants and flowers are similar to Shasta daisies grown in gardens: Leucanthemum x superbum (formerly Chrysanthemum x superbum). Oxeye daisies grow 1- to 2-feet tall and have yellow centers with white petals. They form spreading clumps through their rhizomatous roots, dispersing plentiful seeds and displacing native plants.
Fleabanes (Erigeron annuus) are native plants that are members of the aster family. They, too, are found on roadsides, fields, and disturbed areas, grow 1- to 2-feet tall and have yellow centers with white rays, although their flowers are smaller than oxeye daisies. They can be useful wildflowers in waste areas, but fleabanes have deep tap roots, making them difficult to pull. Their fluffy seed heads, like dandelions, spread these plants far and wide. Plants can serve as hosts to tomato ringspot virus.
Evening primroses (Oenothera biennis) are pretty, yellow-blooming plants, 3- to 5-feet tall, often seen on fence rows, fields, and disturbed areas. This native biennial produces leaves the first year and flowers the second. True to its name, the flowers open in the evening. Evening primroses also have a deep tap root. Another attractive wildflower for waste areas, they produce massive amounts of seed and can be invasive.
Dame’s rocket (Hesperis matronalis), a European import, looks like wild phlox, but if you examine its white, pink, or purple flowers you will notice that each floret has four petals, not five like phlox. Also, its lance-shaped leaves are “toothed,” while phlox leaves have smooth edges. Dame’s rocket is a 3- to 4-feet tall, pretty weed that flowers in May and June. It is often sold in packets of mixed wildflowers. Like other weeds, dame’s rocket spreads aggressively through seeding.
How to control them
Control of all these pretty weeds consists of pulling when possible. Learn to recognize the young seedlings—especially those with deep tap roots that are difficult to remove. You can also cut off the flower heads of older plants before they go to seed. Bag and dispose of these flowers—do not compost!—to prevent seed development and dispersal. Use herbicides as a last resort.
Article written by Judy Deutsch, Extension Master GardenerSM Volunteer.