It’s time to think about Coreopsis. It should not be missing in any garden. I thought of this after receiving a photo from Linda Vaningen of a profusely flowering Coreopsis, the result of the successful germination of California pollinator seed which she had scattered over the area. This happened in mid-May, at the same time and in the same bed where she planted lily bulbs, including the Stargazer variety. She asked if the bulbs benefited from the shade provided by the wildflower plants and I believe the answer is yes. I also planted stargazer lilies under a small tree and they bloomed spectacularly despite only getting a few hours of partial afternoon sun.
Vaningens Coreopsis plants display flowers with bold red markings at the base of their yellow-orange petals; It is the petal color most commonly seen in Coreopsis species, although other shades of yellow and occasional red and pink petals are also seen in select cultivars and hybrids. Vaningen’s species is the lowland core opsis (Coreopsis tinctoria). The most commonly grown species is the large-flowered tick seed (Coreopsis grandiflora). The common name of Coreopsis is due to the shape of its seeds. Koris means “beetle” in Greek and Opsis means “to have the appearance”. The particular bug that Coreopsis seeds resemble is a tick; hence the common name. Incidentally, the most common orchid, Phalaenopsis, is named for the appearance of its flower, since phalain means “moth” in Greek, hence the nickname “moth orchid.”
Coreopsis grandiflora is a perennial plant native to the Southeast, Midwest, and Southwest. It has also become naturalized in parts of California. However, there are seven species of coreopsis native to California (recently reclassified to the closely related genus Leptosyne). Large-flowered tick seeds usually thrive in weed-like profusion in any soil provided adequate drainage is provided. With a height of up to 60 cm and a width of 90 cm, it is reminiscent of the carefree look of an English garden.
The orange-yellow or golden-yellow seen in classic Coreopsis species can also be found in certain low-growing and compact bush Lantana cultivars such as ‘Sunburst’ and ‘New Gold’. Coreopsis and Lantana belong to a small minority of long-flowering perennials that do well in heavy soil or, in other words, soil that drains slowly due to its clay content. As a bonus, Coreopsis attracts beneficial insects such as ladybugs and lacewings, while both Coreopsis and Lantana are visited by birds and butterflies of all kinds. Additionally, Coreopsis is a hardy bloomer that I’ve seen blooming virtually continuously for up to two years. Its death is briefly mourned as it is self-seeding and also spreads vegetatively through underground rhizomes.
Many Coreopsis species flower at this time of year, but perhaps none is more adorable than perennial groundcover Coreopsis verticillata with its lacy foliage. Despite its delicate appearance, it is just as drought and cold tolerant as all other Coreopsis species. Plant it at Lake Arrowhead and it will easily survive the winter. It is a suitable choice for cascading over retaining walls and pouring from hanging baskets and containers of all kinds. The ‘Full Moon’ and ‘Moonbeam’ cultivars have bright sulphurous yellow flowers and dainty, filiform leaves. I’ve seen ‘Moonbeam’ die back in the winter, but then as temperatures get warmer it starts growing rampant again.
The more I study Coreopsis ‘Moonbeam’, the more it reminds me of Geranium incanum, another one of my favorite ground covers. Geranium incanum also has soft, finely braided leaves and, like ‘Moonbeam’, is not at all invasive due to its shallow roots. Geranium incanum grows less than 30cm tall and is self-seeding, but can easily be uprooted if it bothers you where it’s going in your garden. Its flowers have the five overlapping petals of all true geraniums and are magenta-pink in color in this case. Usually Geranium incanum is given exclusive ownership of a garden bed, but I’ve seen it used as an underplanting with white ‘Iceberg’ roses as well. Geranium incanum requires a moderate amount of water to look its best, although it can survive on a single weekly soak.
The Southern California Begonia Society will host a two-day plant show and sale at Sherman Gardens, home to more than 130 unique begonia varieties. The event will take place on Saturday and Sunday, September 16 and 17, from 10:30 a.m. to 4:00 p.m. The show offers a rare opportunity to explore the many species of locally grown begonias. A wide range of begonias not normally available from local nurseries are available for purchase. Experts are available to answer your questions and improve your begonia training. Sherman Library & Gardens is located at 2647 E. Coast Hwy., Corona del Mar. Admission is free for members and $5 for non-members.
Californian of the week: Giant coreopsis (Leptosyne/Coreopsis gigantea) is a curiosity for its thick, succulent stems, feathery foliage, and lush network of 3-inch (7.5 cm) daisies hovering above its leaves. It can grow up to 1.80 m tall and makes a good addition to a succulent garden. It experiences a period of dormancy, during which its luster fades in late summer. In sandy soil, it will self-seed and self-propagating. The only care instruction that comes with giant coreopsis is this: never water it. Irrigation that gets into the soil in the summer will rot the roots. If you’ve wandered along pristine parts of Southern California’s coast for quite a while, you’ve probably seen giant coreopsis growing, whether on flat sand dunes or on the side of cliffs facing the sea. Huge coreopsis can easily be seen growing, for example, next to the beach at Point Dume in Malibu.
If you have a Coreopsis story to tell, please submit it to email@example.com. Your questions and comments about gardening issues or practices, as well as your photos, are always welcome.