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It’s August. Drought or no drought, August is hot and dry in interior northern California and in most cases, our gardens are looking a little…worn, a little worse for the wear of our long, hot, dry summers. Every gardener I know, prefaces a high or late summer visit to their garden with the warning: “You can come, but you won’t be seeing the garden at its best, you know.” PHOTO: Native buckwheat(s) on the slopes of Mt. Eddy, 2015.
High summer and late summer are when many of our native or drought tolerant and heat loving plants can and should shine. Especially those plants adapted to the arid North American West.
In the past few weeks I have enjoyed wildland hikes and cultivated gardens in Siskiyou, Shasta and Butte counties. In each experience, I was drawn to the buckwheats: those eye-catching puffs, and often blankets, of color ranging from white to cream to acid yellow to pink to red. They bloom (sometimes it seems without stop) in our native or drought tolerant gardens from early June through October. Photo: Eriogonum umbellatum and coyote mint (Monardella spp.) in the wild of California’s Monitor Pass. Photo courtesy of John Whittlesey, copyright 2010.
On a recent hike up Mt. Eddy – across the way from Mt. Shasta bordering both Siskiyou and Trinity counties, I was amazed at not only the abundance of buckwheats in flower, but also by their diversity. When I returned home, at the suggestion of botanist friend Julie Nelson, I searched the Cal Flora What Grows Here online tool and in the course of the hike there were at least 17 different species of buckwheats. PHOTO: Native buckwheat(s) on the slopes of Mt. Eddy, 2015.
Forming the genus Eriogonum, buckwheats are miracles of beauty and resilience this time of year. Observing them in the wild provides wonderful inspiration for good garden composition – including companion plants and positioning in terms of drainage and exposure.
The tenacious buckwheats grow on the slimmest of soils on the sunniest and windiest of peaks and slopes, and still they look fresh, whether in foliage, flower or seed. Buckwheats also attract a wide variety of native bees and small butterflies. Almost all species of Eriogonum are considered important sources of food – both food for larval development and sustaining nectar and pollen – for our native and non-native pollinators, especially in the late summer months when other food sources have passed. Photo: A close up of the lovely detail involved in the blossoms of Eriogonum fasciculatum.
The genus Eriogonum belongs to the so-called ‘knotweed’ family, Polygonaceae. Edible buckwheat (Fagopyrum esculentum) is an important food crop originating from Eurasia and is in the same botanical family. While species of Eriogonum do occur elsewhere, the genus is strongly associated with the American Inter-Mountain West, with the greatest number of species occurring in California.
The “Jepson Manual of Higher Plants of California,” states that Eriogonum is named from the Greek for ‘woolly knees,’ as a result of the hairy nodes of some. According to international Eriogonum expert, Dr. James Reveal: “As a native North American genus, Eriogonum (ca. 250) is second only to Penstemon and different species occur from the seashore to the highest mountains. They are among the last plants seen atop the Sierra Nevada and on the “outskirts” of Death Valley. The United States Department of the Interior currently lists some as endangered or threatened species. Some species tend to be weedy, and some of the annual species are aggressively so.”
In part because of the rich diversity within the genus, and because the genus and its relatives have “undergone rapid evolution in arid regions of western North America,” according to Dr. Reveal, botanists are particularly enamored of this group of plants. The groups’ classification system is always being evaluated for possible restructuring.
One or more is bound to flourish and brighten the new drought tolerant plantings in your garden.
Care and Cultivation for the Garden:
In the garden buckwheats like to be planted in full sun – no less than 6 hours a day, in well-draining soil. Resources don’t recommend fertilizing and while a mulch of gravel to improve drainage is not required, it does work well with such dryland plants. If you are growing one of the trickier more alpine species of Eriogonum, then it would be worth it to blend the gravel in the top few inches of soil. Do not overwater these plants, especially not at their base or crowns. Water every 10 days to 2 weeks is sufficient even in the summer.
For an earlier piece I wrote about buckwheats, two Colorado-based home gardeners and plant enthusiasts, Hugh MacMillan and Bob McFarlane, described to me their home gardens – each of which boasts somewhere between 30 and 40 species of buckwheat. These two men met as members of the American Penstemon Society and after they realized their mutual regard for the multitude of Eriogonums, in 2008, they began the formation of the Eriogonum Society whose objectives are 1) enjoying and promoting the use of these plants in the garden. 2) Enjoying and evaluating Eriogonum in the wild. 3) Assembling, developing and sharing information on the propagation, cultivation, identification and distribution of the Eriogonum species. 4. Providing a seed exchange to distribute Eriogonum species seed for use in gardens. 5) Protecting rare and endangered species of Eriogonum. 6. Advancing the overall understanding of Eriogonum from a scientific perspective. Photo: Eriogonum species blooming beside rabbit brush (Chrysothamnus spp.) at Craters of the Moon National Monument in Idaho.
Hugh MacMillan lives near Sedalia, Colorado at an elevation of 6,350. Bob McFarlane lives at 5,400’ in a Denver suburb – and the two gardeners illustrate the range of care that wild buckwheats will tolerate in a home garden. Hugh never feeds his, does not prune them and has watered his no more than 3 times this summer. Bob feeds his with a small dose of all-purpose fertilizer each spring, he waters his as part of his garden once a week, and he cuts his back as needed. The men express to me that perhaps one of the most exciting things about the development of the Eriogonum Society is the potential for seed exchange (open to members only) of good garden selections, because so few species or varieties are currently available in the mainstream nursery trade. PHOTO: Native buckwheat(s) on the slopes of Mt. Eddy, 2015.
In terms of good planting companions, pair buckwheats with plants they might be found with in the wild, or those that will enjoy similar conditions: coyote mints (Monardella spp.), Penstemon heterophyllus cultivars, Nepeta, Achillea, Teucrium, dwarf english lavenders, asters, lupines and low grasses, will all look well and share similar exposure and water/drainage conditions as buckwheats.
Propagation: If you are interested in trying to propagate some of your own Eriogonum, try to sow from seed or take cuttings, which are surprisingly easy despite the fact that eriogonum have atypical stems without consistent nodes. To take a cutting, choose a non-flowering stem, mid-spring before bloom or late- summer/early-fall, after bloom. Cut below or between a node if you can, and follow standard rooting procedure by trimming off lowest leaves on the cutting, dip in rooting hormone and place in well-draining medium. They are not difficult to root. Allow 3 – 5 weeks. PHOTO: Native buckwheat(s) on the slopes of Mt. Eddy, 2015.
Bob McFarlane starts a good many of his plants from seed, some are easy – some are less predictable. He generally soaks his seed in water for 24 hours, then places the seeds in a baggie with soil-less planting mix and places this in the refrigerator for a month. After this chill period, he sows the seeds in soil-less planting mix in pots and places these outside on the north side of his house where they will stay consistently cold until spring, at which time he moves them into a hoop house to grow on. This “mimicking of the seeds’ natural experience works pretty well” for him, although it is not 100% reliable. “One of the things I look forward to sharing among Eriogonum Society members is information on how to germinate and grow different seed successfully,” he said.
A final botanical note:
In an interview several years ago, Dr. Reveal noted that within the state of California, CalTrans is planting Eriogonum fasciculatum var. foliolosum around the state; and it is also now showing up along highways in Arizona.” This tendency sends up red flags for botanists regarding how introduced species of the plants from one area to other area in which those introductions were not originally found could upset the integrity of a regions wild populations. Reveal writes that “more of a problem in southern California (Monterey County south but slowing moving northward) is the island endemic E. giganteum. It will hybridize with another island endemic, E. arborescense on the mainland when the two come into contact. It also hybridizing with the coastal E. cinereum, and that is a major problem especially around Santa Barbara County. I have seen the var. foliolosum spreading rapidly in the San Francisco area, and is now found frequently in the foothills of the inner Coast Range north into Siskiyou County. Because the species, and in particular this variety, are excellent sources of honey for wild and domesticated bees, that too is another reason it is being spread by humans. To what extent this will be a problem in the future is not known as yet.”
For home gardeners considering adding buckwheats, it might be wise to consider how close you live to wild populations and if crossing might be an issue. PHOTO: Native buckwheat(s) on the slopes of Mt. Eddy, 2015.
Garden Selections: Good species of Eriogonum for North State Gardens – valley, foothill and higher altitude – include:
Eriogonum umbellatum ‘Shasta sulfur’, mid-sized compact rounded form that will spread and has striking bright yellow blossoms;
Eriogonum umbellatum var. bahiformis ‘Serpentine Sulfur flower’ has bright yellow flowers and grows 3 – 5’ high and wide.
E. fasciculatum aka ‘California buckwheat’ – a strong form with needle-like leaves up and down the stems and is covered with white blooms late into summer and fall. Can grow up to 6’ tall and wide.
E. fasciculatum var. foliolosum – similar to California buckwheat, but more compact – growing closer to 3’ 3’.
E. giganteum ‘St. Catherine’s Lace’ is a large specimen with eye-catching silver-white foliage and much broader, white flower heads. It can grow up to 6’ by 6’.
E. grande var ‘Rubescens’; is a low matting variety with silvery foliage and warm pink flowers. It grows 8” high and more than 2’ wide.
E. nudum is a matting variety with tall (up to 24’) slender, leafless red-tinged stems topped by sweet little white pom-pom heads.
E. ovalifolium is a low growing, compact silver leaved variety whose flower stems are perhaps 2 – 4”. This variety is particularly sweet in a rock garden setting.
Sources for Eriogonum plants and seeds:
Floral Native Nursery, Chico, Ca http://www.floralnativenursery.com/
Las Pilitas, Escondido and Santa Margarita, Ca http://www.laspilitas.com/
Rebecca Lance- Granite Gardens Rare Plants, Sonora, Ca http://granitegardensrareplants.com/
Sunscapes Rare Plant Nursery – Pueblo, Co http://www.sunscapes.net
For more information see the Eriogonum Society website, or read works by James Reveal or Roger Raiche on-line.
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In a North State Garden is a bi-weekly North State Public Radio and web-based program celebrating the art, craft and science of home gardening in Northern California and made possible in part by the Gateway Science Museum – Exploring the Natural History of the North State and on the campus of CSU, Chico. In a North State Garden is conceived, written, photographed and hosted by Jennifer Jewell – all rights reserved jewellgarden.com. In a North State Garden airs on Northstate Public Radio Saturday morning at 7:34 AM Pacific time and Sunday morning at 8:34 AM Pacific time, every three weeks.