- Author: Kathy Keatley Garvey
If you've lately visited the Ruth Risdon Storer Garden, part of the 100-acre UC Davis Arboretum and Public Garden, you've seen them.
Honey bees nectaring on the Kniphofia "Christmas Cheer" poker plant.
Its stems, stretching 5 to 6 feet tall, are topped with brilliant spikes of reddish-orange tubular flowers. They are Santa Claus-red, honey yellow, and pumpkin orange, all wrapped in one.
The genus, Kniphofia, honors Johann Hieronymus Kniphof (1704 -1763), a German physician and botanist. Botanist Conrad Moench (1745–1805) bestowed the name.
Everywhere the plant goes, it spreads cheer.
Honey bees, buzzing out of their their hives when the temperature outside hits 55 degrees, spread their own kind of cheer, bringing back life-nourishing nectar to their sisters and queen bee in the dead of winter.
Cheers.
By T. Eric Nightingale, UC Master Gardener of Napa County
It may surprise you but California has a good deal in common, environmentally speaking, with South Africa. Both have a variety of climate zones, many of which overlap. Many plants from South Africa will grow well in Napa Valley, especially with proper care.
You are doubtless already familiar with some South African plants. Red hot pokers (Kniphofia uvaria), with their spiked yellow and red blooms, are used frequently in Bay Area gardens. Two South African irises, Dietes bicolor and Dieties grandiflora, are present in what seems like two out of three shopping center parking lots. Even the popular bird of paradise, Strelitza reginae, is native to this region.
Many other less-common South African plants will also grow well in Napa. If you are curious about a new plant but unsure if it will grow well in your area, look into its native climate. While the Bay Area has many microclimates, we generally have a warm-summer Mediterranean climate.
This description comes from the Köppen climate-classification system used by many to identify climate zones around the world. You can find a color-coded map online showing areas with similar climates. If a plant comes from an area with the same color code as your garden, it should be a good choice for you. Compare the climate maps of California and South Africa and you will see many of the same colors.
We have native salvias here in California, but Africa also has some members of the genus. A personal favorite of mine is Salvia africana-lutea. It has a pleasant smell and small, dusty-green leaves. The flowers are rust-brown, giving rise to its common name: dune sage. That may not sound appealing, but the blooms and leaves create a color contrast that is attractive in the proper setting.
Another lovely plant in this genus is Salvia dolomitica, conveniently known as South African sage. Its silver-gray foliage makes a background to delicate purple flowers. The calyx—the leaf-like structure that holds the flower—starts out burgundy but turns pink with age. However, my favorite thing about Salvia dolomitica is its fragrance, an intoxicating blend of floral and herbal aromas befitting the plant's elegant appearance.
While some South African plants, such as Dietes, feel so at home here they need almost no help from us, others need a little extra care to remain healthy. Often, this means amending your garden soil to improve drainage or protecting the plant from frost. This is particularly true of plants in the Proteacea family. Leucospermum cordifolium is a shrub that grows large, colorful flowers with extended styles, often called “pincushions”.
A similar plant in the Protea family, the Leucodendron salignum,produces a flower that resembles a pine cone in shape, but in colors ranging from yellow to silver. These plants must have exceptional drainage or their roots will quickly rot. They are also sensitive to frost and can only take low-phosphorus fertilizer. Even though they require this special attention, they are drought tolerant once established. And oh, are the flowers worth the effort!
Many succulents are native to South Africa and will perform well in Napa Valley. Aloe brevifolia is a stubby-leaved, clumping plant that produces orange flowers in fall and winter. It is frost tolerant as well, which is not a common trait in a succulent. Delosperma cooperi, a personal favorite, is a vine-like plant that forms dense mats along the ground and over the edges of planters. It is very cold hardy and produces dozens of pink flowers. When the blooms appear in spring and fall, they will add thick swaths of color to your garden.
Some of the most striking South African plants are bulbs. Freesia, Crocosmia and Gladiolus are familiar, but there are many others. One of my personal favorites is Babiana rubrocyanea, whose flowers have vibrant purple petals with a bright red center. Equally as attractive is Sparaxis elegans, which produces a delicately-colored orange and maroon bloom.
These bulbs are interesting because they thrive in clay soil and are summer-deciduous. During the hot months they die back to the ground and require no water at all. In fact, more than a sprinkling of water in summer will likely cause them to rot. Come spring, however, their leaves return and the flowers burst forth in all their glory.
I encourage you to explore the many plants from South Africa. You just might find a perfect plant for your garden.
Next workshop: “Succulents Celebration!” on Saturday, July 20, from 9:30 a.m. to 11:30 a.m., at the University of California Cooperative Extension, 1710 Soscol Avenue, Napa. Learn why succulents have become the trendiest members of the plant kingdom. For more details & online registration go to http://napamg.ucanr.edu or call 707-253-4221
The UC Master Gardeners are volunteers who provide UC research-based information on home gardening and answer your questions. To find out more about upcoming programs or to ask a garden question, visit the Master Gardener website (http://napamg.ucanr.edu) or call (707) 253-4221 between 9 a.m. and noon on Mondays, Wednesdays or Fridays.
- Author: Kathy Keatley Garvey
If you're thinking about adding more bee friendly plants to your garden but you're concerned about the drought, the UC Davis Arboretum has the answers.
The arboretum will host its public spring clearance plant sale on Saturday, May 17, from 9 a.m. to 1 p.m. at the UC Davis Arboretum Teaching Nursery on Garrod Drive.
You'll find a large election of Christmas natives and Arboretum All-Stars. (Members of the Friends of the UC Davis Arboretum and the Davis Botanical Society receive 10 percent off their purchases. And yes, you can join the Friends on May 17.)
One of the plants we like--as do the birds and the bees--is Kniphofia "Christmas Cheer," also known as a red hot poker and torch lily. Ellen Zagory, horticulture director of the Arboretum, describes it as "a torch lily on steriods. It gets big and puts out a large display of showy flowers in winter and long into spring."
Yes, it does.
We remember taking a photo of the Christmas Cheer on Christmas Day in the Arboretum's Storer Garden. The bees didn't know about the winter break. Neither did a finch.
Break? What break?
In a recent newsletter, Zagory wrote about some of the plants that will be available for sale.
“On campus we have fairly heavy soil and water that's high in bicarbonates and boron, so I always think…if it grows well here, it will do even better elsewhere. In light of limited water supplies and rising water prices we need to think even harder about plants that can survive with low or very low quantities of water, but they can still be pretty. You'd never know these were drought-tolerant considering the seasonal impact and drama they provide!”
The Arboretum kindly provides a list of available plants that you can download from its web page.
The bees--and the birds, butterflies and others engaged in animal/plant interactions--will thank you.
- Author: Karen Metz
I have always been impressed with the drama of hot pokers, Kniphofia. However several things held me back from purchasing them. First I don't like buying plants whose names I can't pronounce and Kniphofia ( knee fof ee a ) has had me stymied for a long time. When I was Googling Kniphofia, one of the first categories that came up was pronunciation, so I don't think I am alone. To me the name sounds like a sneeze; I get this uncontrollable urge to say "Gesundheit " every time I hear someone say it.
Secondly, most of the plants I have admired have been very large, with mounds of foliage reaching three to four feet high and sometimes five to eight feet wide and that's not even counting the blooms. I have a small front yard and a small border area available so I thought I would have to forgo a hot poker. (Note, in researching this article I found the most charming turn of phrase on the Digging Dog Nurserysite. Instead of calling a garden small, they called it space-thrifty.)
But then at Annie's Annuals I found Kniphofia 'Wol's Red Seedling'. This hybrid was carefully bred in England. Kniphofias are originally from South Africa, but were brought to England in the 1800s and are very popular there. This little darling has leaves that top out at a foot and flower spikes to two feet. It has a brilliant red color that is described by several sites as the reddest of all the pokers. They mentioned it could even be grown in a container. You guessed it, I brought one home.
I tucked it in the front yard in the border by the faux dry stream bed, amongst the 'Stella d'Oro' dwarf day-lilies and the lavender. The first summer it had three small blooms and I was a little discouraged. This year I have six blooms already, and the plant looks lovely, especially with the afternoon sun back-lighting it.
Kniphofias are deer resistant.They can handle clay soil, as long as it drains well. They are drought tolerant but do like water when the blooms are forming. If it is too dry at that point they will not bloom.
- Author: Kathy Keatley Garvey
Bee specialists like to point out that the yellowjacket is a carnivore and the honey bee is a vegetarian.
They are, indeed. The yellowjacket is an aggressive predator that seeks protein-rich foods for its colony, while the honey bee--usually quite passive unless it's defending its hive--gathers nectar and pollen.
If you've ever watched a yellowjacket invade a honey bee hive or prey upon other insects--or grab a bite of chicken from your barbecue or scavenge rotting fruit--you know how aggressive it is.
We watched a western yellowjacket, Vespula penyslvanica (as identified by Lynn Kimsey, director of the Bohart Museum of Entomology and professor of entomology at UC Davis), forage on a cluster of red-hot pokers along a road leading to Tomales, a tiny town in Marin County.
This wasn't a "red" red-hot poker, though. It was yellow. Varieties of the Kniphofia genus (the genus was named for 18th century German physician/botanist Johann Hieronymus Kniphof) now appear in such colors as orange, coral, cream and yellow.
Rather fitting that a yellowjacket was on a yellow red-hot poker!
We caught it in flight as it headed toward the tubular flowers and watched it grab a few tasty morsels, an unsuspecting spider or two, to carry back to the nest. (It also sips nectar for flight fuel.) When it emerged, it was dotted with pollen grains, so you could say that sometimes it's a pollinator, too. But not a significant one...
The western yellowjacket, native to the western United States, is a major pest in Hawaii, where it was first discovered in 1977. Erin Wilson, a former postdoctoral scholar in the Louie Yang lab in the UC Davis Department of Entomology, studies this social, ground-nesting wasp.
Wilson, who launched the vespularesearch.com website, describes it as a "vacuum cleaner" that wreaks ecological havoc among the native species in Hawaii.
“The introduction of non-native organisms is a leading cause of imperilment of native species,” says Wilson, who has studied the western yellowjackets at two sites: the Hawaii Volcanoes National Park on the island of Hawaii and the Haleakala National Park on Maui since 2004.
Scientists have found that the incidence of perennial or overwintering colonies is higher in Hawaii than in its native range.
Compared to annual colonies, these overwintering perennial colonies can collect twice as many prey items and produce 10 times the worker force, Wilson says. Some perennial colonies are huge, their size linked to Hawaii’s mild climate and the ability of the yellowjackets to establish perennial colonies. How huge? One Maui colony yielded 600,000 individuals. Compare that to a typical California colony of less than a few thousand wasps.
Read the PBS piece about this invasive insect in Hawaii and see it "stinging" the camera lens.