I was looking at one of my planters the other day and was surprised by flowers I had never seen before. These flowers were not to be found on any of my neighbors’ plants, so I was curious as to how they may have gotten into my garden. In all likelihood, their seeds were in the soil of a containerized plant I had acquired and planted nearby, or they had been deposited there in the excretion of a bird or rodent.
As I mentioned in last week’s column, I have a squirrel who has made itself at home in my garden, so maybe I benefited from its having foraged, swallowed, digested, and then deposited the seeds of the plants that produced these unusual flowers.
I thought the leaves looked like those on Calendula, but knowing that foliage does not necessarily correlate with plant identity and that flowers are what matter in this regard, I took a photo and uploaded it to an excellent app for plant identity — Pl@ntNet — which is entirely free. I learned that the flowers belonged to Calendula stellata, an understandable species appellation since the flowers did have a starry (“stellata” means “star,” or “starry,” in Latin) look. Calendula is the genus name since its species are among the first flowers to bloom in the calendar year, although they may open up in our part of the world at any time except for the hottest days of summer.
My Calendula is not customarily seen since its flowers, although interestingly shaped, are not as large or a vibrant as those on the typically planted Calendula officinalis. Still, the flowers of that species are the same colors — yellow and orange — as those on my stellata species.
Pot marigold is another name for Calendula. Here, “pot” is a shortened term for potherb, which include a number of leafy greens such as spinach, kale, collards, and chard, most herbs, and even some weeds, such as lamb’s quarters and pigweed. There are also a number of ornamental flowering annual plants that merit the potherb designation, and Calendula is usually the first on this list, accompanied by nasturtium and alyssum.
The daisy family (Asteraceae) counts Calendula and marigold among its members and is the largest plant family on earth, including more than 30,000 species. You could easily plant a garden consisting of nothing but daisy family members. This would probably be a pest-free garden because of the attraction of daisy flowers to a wide variety of beneficial insects, including ladybugs, lacewings, hoverflies, and parasitic wasps. Daisies are unique in having two kinds of flowers or, technically speaking, florets: inner disc florets that appear in the center, each of which consists of colorless petals fused to its reproductive structures, and outer ray florets, each of which shows off a colorful petal known as a ligule. Both kinds of florets yield a single seed. Each type of floret has an appeal to different pollinating insects, which explains the variety of beneficial insects found on these plants.
Perennials of every description are best planted in October. Days are getting shorter, so no matter how hot it gets, the heat’s duration is limited. Planting now is especially sensible in Southern California since you give roots the opportunity to knit with the soil over the next several months before our long, hot and dry growing season begins. Root systems will expand in October due to residual heat from those long, hot summer days.Getting back to members of the daisy family, I could write 10 columns about them and still not adequately cover the subject, but here, at least, are some of the more noteworthy daisy species.
First and foremost in this plant category are gerbera daisies (Gerbera jamesonii). They are not only among the prettiest, but also among the toughest perennials you can grow. Blooms reach five inches across and appear in flaming red, pink, yellow, orange, and in all possible versions and mixtures of these colors. As long as gerberas are given tough love, they will last for decades. They do not need to be fertilized, and once established, they will not need water more than once a week, except perhaps for an additional weekly soaking in blisteringly hot weather. Allow the soil to go bone-dry before watering. Cut them back around the first of the year, removing spent foliage, and they will regrow with the onset of warm weather.
Gerbera daisies normally bloom from spring to fall, but where the winter is mild, they will flower in that season too. They are suitable for planting anywhere in Southern California south of the Antelope Valley. Gerbera daisies abhor overhead irrigation that can lead to mildew problems and grow splendidly when surrounded by gravel or wood chips. When planting, make sure that the crown, where the roots meet leaves, is elevated above the soil surface and not in contact with woody mulch to prevent suffocation of this sensitive area and premature death. Gerbera daisies have a clumping growth habit and may be divided at the roots, as long as separated clumps each have a least one crown, for propagation purposes. Finally, gerbera flowers are famous for being cut and floated in clear glass bowls as table centerpieces
One of my favorite daisy genera is Coreopsis. Of the many species, Coreopsis grandiflora is a yellow-orange perennial that grows with weedlike profusion in every type of soil. Coreopsis evokes the carefree English garden look. There is an exotic California native succulent known as Coreopsis gigantea. Growing up to 10 feet tall, I have seen it flourishing on cliffs along the Malibu coast. Its yellow flowers, which are three inches across with ferny foliage and thick succulent trunks, make it a most distinctive selection for a dry garden.
Once you’ve seen a Santa Barbara daisy (Erigeron karvinskianus) it’s hard to live without it. Picture a proliferating mound that spreads or spills or drapes down and around and is covered with probably a thousand miniature pinkish-white daisies. The Santa Barbara daisy, which is actually native to Mexico and Central America, is meant not only for sunny garden, block wall, or walkway border planting, but tolerates a fair dose of shade as well as poor soil and drought. It is eminently suitable for patio and balcony planters and hanging baskets as well. Santa Barbara daisy flowers 12 months of the year.
Back in the last decades of the 20th century, the dazzling white, trailing African daisy (Osteospermum fruticosum) was a staple of highway landscaping, so much so that it earned the sobriquet of “freeway daisy.” The plant proved astonishingly tough, and although it developed dead patches now and again, there wasn’t a more stunning ground cover in full bloom. After a while, you began to see a closely related violet-purple freeway daisy planted for diversity’s sake. It was attractive enough, but a far cry from its blindingly white counterpart.
Because most chrysanthemums flower in the fall, botanists have deemed them “short-day plants” as opposed to “long-day plants” that flower in the spring and summer or “day-neutral plants” that bloom throughout the year. Yet research has proven that so-called short-day plants actually flower in response to long nights. If you plant chrysanthemums where they are lit up at night by street lamps or patio lights, they may never bloom.
A Shasta daisy (Chrysanthemum maximum) flower has the classic daisy look: a large yellow center surrounded by white petals. Shasta daisies do not bloom until the second year of growth. But once established, they will amble through your flower bed in due course. Feverfew (Chrysanthemum parthenium) has pungent, lacy leaves and myriad, miniature daisy flowers. Feverfew reseeds with alacrity and some consider it a weed. It is best suited to rugged, low-maintenance areas. Costmary (Chrysanthemum balsamita) has a delightful scent that is part lemon, part mint, and will grow in the worst soil, provided it gets regular water. If you want a real treat, pick up a packet of Chrysanthemum carinatum seeds at the nursery.
These mums produce tri-color blooms against a background of semi-succulent, finely cut foliage. Marguerite daisy (Argyranthemum frutescens) blooms intensively, creating 3-foot mounds of pink, sulfur yellow, ruby red, or white flowers. If flowers are regularly removed as soon as they fade, you will see several waves of bloom throughout the year. Blanket flower (Gaillardia grandiflora) is so named because its flowers invoke the colors of blankets woven by indigenous tribes. It does extremely well in warm weather, growing into sizable clumps to two feet tall and self-sows.
California native of the week: If I were to make the California native of the week nothing but daisies, I could find one of them per week for nearly 20 years before their number, which exceeds 900 species and subspecies, was exhausted. One of the most memorable of these is beach aster or seaside daisy (Erigeron glaucus). It forms clumps to one-and-a-half-feet tall with blue-green foliage and, depending on variety, pink or lavender flowers. You will need to give it good light, but keep it out of the hot sun, unless you live along the coast, to prevent leaves from burning.
Do you have a daisy species tale to tell? If so, send it along to joshua@perfectplants.com. Your questions and comments, as well as gardening conundrums and successes, are always welcome.