Continuing our focus on select species of Eriogonum (wild buckwheat), this week's discussion features California buckwheat (E. fasciculatum).

First, here is a quick review of characteristics common to all of California's wild buckwheats. They are hardy colonizers of tough soils and dry ecosystems, such as coastal scrub and chaparral. They can live at the edges of deserts and up to high elevation tree lines. Their blossoms are important to pollinators such as bees, butterflies, and hummingbirds, providing them with flowering food long after other natives have gone dormant. Buckwheat flowers have tall, slim, delicate anthers that seem to float above the flower mass, creating their signature lacy or frilly look. Because they hybridize indiscriminately, at last count there were over 250 species to explore and enjoy.

Species Focus - California Buckwheat

Eriogonum fasciculatum, best known as California buckwheat and sometimes called eastern Mojave buckwheat or flat-topped buckwheat, is found primarily on dry slopes and canyon washes in the American West, including Nevada, Utah, and Arizona, in addition to California and reaching as far as Mexico's northwest. In California it is the most widespread of the shrubby buckwheat species, found in abundance in the southern half of our state. It is less common in the Central Valley and northern reaches, although it has proven to be a successful a landscape plant in Butte County. Its adaptation to our Mediterranean climate allows it to survive on as little as seven inches of rain annually.

This buckwheat species is evergreen and blooms from May through October. It can grow to nine feet high and six feet wide (almost as big as its largest family member, the giant buckwheat), but usually reaches around four feet in height and width. E. fasciculatum is a very pretty plant when flowering – its many small, frilly white or pink flower clusters are held aloft on flexible, slender stems above rafts of narrow green leaves. The blossoms turn rusty or burnt orange in color as they dry late in the season, adding muted fall colors to the landscape. Leaves are fuzzy on the underside, and either smooth or fuzzy on top.

According to California Native Plants for the Garden (an excellent resource for gardeners looking to shift from traditional thirsty landscaping to a yard that conserves water and sustains pollinators), the hairs on E. fasciculatum's leaves contribute to its ability to withstand the dry and harsh conditions of the ecosystems it inhabits. Hairy leaves provide insulation from heat and protection from direct sunlight as well as a boundary air layer that reduces water loss.  

Its genus name, fasciculatum, comes from the Latin word meaning “bundles,” used in botany to refer to the growth habit of plant leaves. It shares this genus name with many other plant species.

California buckwheat makes excellent honey, and the plant is billed as the most important native source of honey in the state. (Honey made from yellow star thistle may be just as delicious, but that plant is an aggressive and invasive intruder!)

Native American peoples in the west and southwest used different parts of the California buckwheat for nutrition and medicine. The Cahuilla tribe of what is now the greater Palm Springs area used this plant in many ways: they treat headaches and stomach pains with tea made from its leaves; treated colds and sore throats with tea made by steeping its roots; and applied poultices made from pounded roots to wounds. Cahuilla peoples also treated heart problems with tea from the dried flowers and dried roots of E. fasciculatum. Modern science has verified that a chemical compound common to several plant species including Eriogonum can be beneficial to hearts (USDA Plant Profile).

The Natural Resources Conservation Service, a division of the US Department of Agriculture, identifies and experiments with natives and other plants for their conservation value - primarily their ability to protect soils from erosion, revegetate burn scars, and provide habitat and sustenance to wildlife as an aid in controlling agricultural pests. Their experiments with California buckwheat show that it has superior value in all three of these categories. The USDA Plant Profile for E. fasciculatum classifies its performance as a conservation plant on critical areas and problem soils as “excellent.” It receives another “excellent” mark for providing “nectar sources for beneficial insects when planted next to crops as part of an (IPM) Integrated Pest Management program.” They recommend the use of its seeds in seed mixes introduced to burn scars for revegetation. Finally, California buckwheat gets USDA bonus points because it is “ideal for environmental enhancement uses” (government-speak for “beautiful in the landscape”).

If you plant E.fasciculatum in your yard, be sure to locate it away from regular irrigation sources and in soil that drains well. It will be happy if you give it problem soil (rocky, alkaline, etc.). Make sure it has room to expand or even take over, because it can become invasive. It is an attractive and valuable addition to any drought resistant, native pollinator garden.

A number of buckwheat species, including a large lovely California buckwheat, are thriving in the Butte County Master Gardener Demonstration Garden at Patrick Ranch (located just south of Chico on the Midway). At this time of year, they are abuzz with bees, and visited often by butterflies. Due to our current safety measures, no human visitors are allowed, but we look forward to seeing you there in the future, so you can appreciate the fascinating buckwheat family and our gardens in general.

For more information on E. fasciculatum, see the following sources:

Calflora

United States Department of Agriculture, Natural Resources Conservation Service, Plants Database

Carol Bornstein, David Fross, and Bart O'Brien, California Native Plants for the Garden (Cachuma Press, 2005)

The UC Master Gardeners of Butte County are part of the University of California Cooperative Extension (UCCE) system, serving our community in a variety of ways, including 4H, farm advisors, and nutrition and physical activity programs.  Master Gardeners bring practical, scientifically-based knowledge directly to our community. For help with gardening in our area, visit our website. If you have a gardening question or problem, call the Master Gardener Hotline at (530) 538-7201 or email mgbutte@ucanr.edu.

It's hot. Tomatoes like heat, right? Actually, tomatoes like warm weather, between 65 and 85 degrees. When temperatures soar past 95, tomatoes stop growing. In that kind of heat, their flowers fail to pollinate and instead they dry up and drop off, putting a pause on the production of new fruit. Tomatoes that have begun to color will halt at orange and fail to turn red.

We can't control the sun, but there are a few things we can do to help tomatoes stay productive in our hot valley summers. In the first place, plant tomatoes in a spot that gets sun in the morning and filtered sun in the afternoon. If tomatoes are sitting in the blazing sun all day, create afternoon shade for them with a sheet of row cover material or shade cloth clipped to the west-facing side of the support structure on which the tomatoes are growing. Arrange the cloth over the tops of the plants to protect from mid-day sun as well. Leave the east side of the plants free for morning sun and air circulation, and to allow pollinators to reach plants. Clothes pins or binder clips can be used to secure the row cover material or shade cloth and are easy to take off to allow access to harvest. Use of shade cloth can drop the ambient temperature by as much as 10 degrees and is often sufficient to keep tomatoes in that sweet spot of productivity.

If your tomato plant has good green leaf color, is flowering and has fruit developing, but its leaves are curling up, you are experiencing a common summer problem for tomatoes in our area. The culprit again is most likely heat. Tomato leaves transpire water from the undersides of their leaves. When a tomato plant can't take in as much water as it is losing, its leaves will curl up. This occurs when the soil is too dry, the temperature is too hot, or it's too windy. Check soil moisture by poking a finger an inch into the soil. If it's dry, it's time to water. Leaf curl is the tomato's way of reducing leaf surface area to reduce water loss. Curling up will not affect fruit production or the health of the plant.

Upward leaf curl can also result from overwatering. Too much water can cause roots to rot. Rotten roots will not be able to pull in moisture and, though water is abundant, the tomato plant can be dying of thirst. Again, a finger into the soil will tell you if the soil is too wet. The plant will not recover from root rot.

There is one further thing to rule out before you rest in the tranquility that upward leaf curl requires no action on the gardener's part: pests. Check a few leaves to be sure the curl isn't harboring an insect or caterpillar cocoon. No caterpillar, no problem. Your tomatoes are fine in their self-protective upward curl.

A two- to three-inch layer of mulch around tomatoes will help the soil retain moisture and stay cooler. Straw, wood chips, chopped leaves, and grass clippings are all fine mulches for this purpose. Mulch also helps keep moisture around tomato plants more even; this can keep the fruit from cracking and help to prevent blossom drop.

Ever wondered how to encourage sweeter tomatoes? Here temperature and sun are your friends, to a point. Ninety degrees and lots of sun will give you a sweeter tomato. At 100 degrees, fruits develop color on the outside, but stay green on the inside: not tasty. So when temperatures soar, pick tomatoes that have begun to color and allow them to ripen indoors. Remember: never refrigerate a tomato.

For the health and beauty of your tomatoes, give them a bit of protection in the heat of summer. Mulch and a bit of shade will help in maintaining happy plants that produce delicious tomatoes.

For more information see ANR Publication on Growing Tomatoes in the Home Garden.

The UC Master Gardeners of Butte County are part of the University of California Cooperative Extension (UCCE) system. To learn more about us and our upcoming events, and for help with gardening in our area, visit our website. If you have a gardening question or problem, email the Hotline at mgbutte@ucanr.edu (preferred) or call (530) 538-7201.

This final discussion of Eriogonum, or wild buckwheat, examines three beauties that are grown at the Master Gardener Demonstration Garden at Patrick Ranch: E. nudum; E. umbellatum; and E. grande var. rubescens (previous articles in this series have looked at E. giganteum and E. fasciculatum).

A quick reminder about characteristics that wild buckwheats have in common: they are tolerant of harsh conditions such as drought, rocky soil, and blasting summer heat, and are able to persist in hot desert and chaparral as well as montane environments. Most hate having wet feet, so will not grow in marshy or riparian ecosystems or heavy clay soils. All provide excellent sustenance to pollinators. Pertinent to two of the species discussed below is the wild buckwheat's penchant for hybridization, which has not only resulted in over 250 Eriogonum species, but also a large number of varieties within species.

Species Focus – Eriogonum nudum

A progenitor of up to sixteen subspecies and variants, E. nudum is distributed widely throughout the western quadrant of North America, from Alberta and British Columbia in Canada down to the southern border of California and the eastern border of Nevada. Its ability to thrive along the coast at sea level and in wet conditions make it an outlier in the buckwheat realm.

Being deciduous also makes it different from most wild buckwheats. Its life cycle starts in the spring, when it puts out ground-hugging green leaves in a rosette pattern. From there, it sends up slender, hairless or bare (nudum) stems, often dividing into two or more stems towards the top half, which begin to bloom in May and last through at least August. The flowers are frilly balls of white, pale pink, or yellow. The bare stems of E. nudum, topped with rounded flower clusters above which float delicate anthers, are a dramatic scene in the late summer landscape.

The stems and flowers can reach up to six feet high, but usually clock in at three to four feet. The entire display dies back in winter, to begin again the following spring.

The many common names of this plant include naked, nude, or barestem buckwheat, and naked-stemmed Eriogonum. Native American peoples found several uses for its hairless stems: the Karuk tribe of Siskiyou County and the Miwok tribe of California's Central Coast ate young, tender stems raw; while older stems were upended with the leaves still attached for use as brooms. The Kawaiisu peoples of southeastern California used the hollow stems as smoking pipes and drinking straws.

Species Focus – Eriogonum umbellatum

This species, best known as sulphur or sulphurflowered buckwheat, boasts even more subspecies and variants than E. nudum: up to forty! While most naked buckwheat species resemble one another, the numerous sulphurflowered buckwheat species appear in many guises: from a little perennial herb less than four inches tall to a rambling shrub six feet high and wide. Leaves can be wooly and hairy or smooth and bare. The flowers vary wildly too, ranging from white to purple, orange, and a bright (sulfurous) yellow.

Generally speaking, though, sulphurflowered buckwheat forms a low, broad mat from four inches to two feet tall and wide. The clusters of tiny flowers are borne on stems ranging from three to sixteen inches tall. According to the US Department of Agriculture's Plant Profile, “floral displays can color entire slopes starting in June at lower elevations and continue into September or October at higher elevations.”

The Latin genus name comes from umbel, a botanical term for flower clusters that are made up of many short flower stalks radiating out from a common point to form a flat or curved surface. If “umbel” brings to mind “umbrella” that's because the words are semantically related –the stalks emerging from the center resemble the spokes of our umbrellas.

Sulphur buckwheats are native to the western mountains of North America, and are found in roughly the western third of Canada and the U.S., as far east as Colorado and New Mexico. They can live at elevations of up to 12,000 feet. As with other buckwheats, they are not only an important food source for bees and butterflies, but animals as large as deer and mountain sheep will browse their leaves.

Throughout the American and Canadian west, Native peoples found a number of medicinal uses for various parts of the sulphur buckwheat. Paiute and Shoshone tribes mashed leaves and roots into a poultice for both lameness and rheumatism, and drank a hot tea of simmered roots for colds or stomachaches. Closer to home, the Klamath Indians soothed burns with a poultice made of its leaves.

Species Focus – Eriogonum grande (var. rubescens)

A mere three subspecies belong to E. grande (Island or Redflower buckwheat), and all are native to California's Channel Islands. E. grande var. grande is found on several of the Channel Islands, and the very rare E. grande var. timorum is native to the southern Channel Island of St. Nicolas. The only one that is available horticulturally (according to Calscape) is the variety planted at the Master Gardener Demonstration Garden: E. grande var. rubescens. This buckwheat is commonly called red-flowered buckwheat or simply red buckwheat and is extensively planted in native gardens state-wide due to its beauty, compact form, and blooms that last up to seven months.

E. grande grows naturally on the dry cliffs of the Channel Islands, in small mats of leaves densely clustered at the base of the plant. Leaves are dark green on their upper surface and very pale underneath, and round clusters of flowers bloom atop approximately one-foot high branching stalks. It flowers from April through October, providing food to many pollinators, including eleven named species of butterflies. Although its species name comes from the Latin for red or reddish, the red-flowering buckwheat can also sport blossoms in hues of white, cream, and pink.

Which brings us to the fact that grande is an odd name for a species known for its neat and petite growth habit, and which spreads neither quickly nor very far. (Maybe this is why a certain coffee chain got the idea to name its smallest coffee size “grande?”)

The best thing about planting long-flowering natives in your yard is the sheer volume of bees and butterflies that will visit to feed. That, their low water needs, and signature frilly blooms make wild buckwheats a choice addition to your native, drought-resistant garden.

I hope this peek into a few of the many wild buckwheat species will entice you to plant some in your garden. Please be sure to check the Calflora website for photos of each of the 256 wild buckwheat species.

The UC Master Gardeners of Butte County are part of the University of California Cooperative Extension (UCCE) system. To learn more about us and our upcoming events, and for help with gardening in our area, visit our website. If you have a gardening question or problem, email the Hotline at mgbutte@ucanr.edu (preferred) or call (530) 538-7201.