A version of this article was originally published in the September 2024 issue of Grapevine, The Salt Spring Island Garden Club Newsletter.
Oxeye Daisy (Leucanthemum vulgare)
A familiar and cheerful sight on the roadside, the oxeye daisy is easily recognised by its open white flowers with yellow centres. Native to Eurasia, Oxeye daisy was introduced to North America in the late 1700s through seed mixes and as an ornamental. By 1800, it had become widely established across the continent, and is now a persistent invader of roadsides, pastures, and rangelands (Invasive Species Council of B.C.). Each flower can produce up to 26,000 seeds, which can live in the soil for up to 20 years! The flower displaces native plants, reducing forage for livestock, insects, and wildlife alike. The weed is especially problematic in the Cariboo, Okanagan, Peace River, Thompson, and Omineca regions. Oxeye daisy is designated as a Regional Noxious Weed by the B.C. Weed Control Act.
If you take a minute to observe oxeye daisies growing next to native flowers, you will likely see more insects, including pollinators, on the native flowers. Despite this, I have sometimes wondered if the oxeye daisy provides a critical food source at times when native flowers are blooming less, such as in midsummer. That said, the oxeye daisy should be removed where possible, as it does not provide the ideal food for native insects, birds, and animals.
English Daisy (Bellis perennis)
This low-growing perennial weed is found throughout my lawn, blooming prolifically in the spring and dying back by mid-summer. Its flowers can vary from white to pink in colour, and its leaves are basal, short-stalked, and elliptical, oval, or circular in shape. If you have tried to dig it out, you know how its tenacious roots spread out and cling to the soil. Although not listed as an invasive species in B.C., it is aggressively invasive, and can easily take over disturbed areas. The English daisy does not provide the correct pollen and nectar needed by native insects, thus it is best to remove it.
Removal
Both oxeye and English daisies are best removed by digging them out (there are handy tools available for this, so you don’t have to bend) or if you’re really desperate, glyphosate is an effective herbicide.
Plant These Instead
It is difficult to find alternatives for these open, white, fast-growing and abundant flowers, however, we have Erigeron and Arnica species as local and attractive alternatives.
Cutleaf Daisy / Fleabane (Erigeron compositus)
With over 20 species of Erigeron occurring within our region, it can be tricky to identify them to a species level, however, the cutleaf daisy is distinct for its divided hairy leaves, hairy stem, hairy bract under the flower and its low growth habit. It is usually under 25 cm (10”) in height, anchoring into the ground with a taproot. It spreads via horizontal underground rhizomes and prefers well-drained soil. Blooming from May to August in southern B.C., it is ideal for drought-prone areas of your garden, as well as rock gardens. I don’t know how widely available this plant is in local nurseries, but it appears relatively easy to grow from seed.
Showy Daisy/Fleabane (Erigeron speciosus)
Also of the Erigeron genus, the Showy Daisy has narrow, white, pink or purple ray flower petals and yellow disk flowers. Showy daisy is an upright, branching, and clump- forming perennial. It is a prolific bloomer , flowering all summer and into fall, and a favorite of pollinators. Showy daisy is quite variable in height but is generally 24”(60cm) ’tall, although it can reach 1 meter tall. Preferring full sun, this plant is tolerant of a variety of soil conditions and full sun to part shade.
Arnica (Arnica spp.)
Although the flowers of the Arnica species are yellow, they have the upright habit and prolific and long-lasting blooms of the invasive daisies. On the coast we have Streambank Arnica (A. amplexicaulis), Mountain Arnica (A. latifolia) and Hairy Arnica (A. mollis), which all prefer moist meadows or moist, open forests. Size varies from 1-4’ (12”-60”) in height with tolerance for full sun, but a general preference for part shade.
Other Alternatives
- Douglas’ Aster (Aster subspicatus)
- California Aster (Aster chilensis)
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