Think bees. Think butterflies. Think plants that will attract them.
Members (you can join online or at the gate) can peruse and purchase plants from 9 to 11 a.m., and the general public from 11 a.m. to 1 p.m. Members save 10 percent off their plant purchases, while new members receive an additional $10 off as a thank-you gift.
You can chat with the Arboretum folks to pick out that special plant you're seeking. They also provide an online list of available plants and/or you can download The Life After Lawn: Garden Gems Plant List.
Many of the plants at the sale are All-Stars. What's an All-Star? The Arboretum horticultural staff has identified "100 tough, reliable plants that have been tested in the Arboretum, are easy to grow, don't need a lot of water, have few problems with pests or diseases, and have outstanding qualities in the garden." Many are California native plants and support native birds and insects. Most All-Star plants can be successfully planted and grown throughout California.
If you miss the Oct. 7th sale, not to worry. There are two more fall plant sales:
Saturday, Oct. 21
Open to the Public: 9 a.m - 1 p.m.
Saturday, Nov. 4
Public Clearance Sale: 9 a.m. - 1 p.m.
It's a good idea to BYOB (Bring Your Own Box), BYOW (Bring Your Own Wagon) or BYOC (Bring Your Own Cart).
While you're there, check out the 100-acre Arboretum, including the nearby Ruth Risdon Storer Garden (aka Storer Garden), a Valley-wise garden,and the Carolee Shields White Flower Garden and Gazebo (aka White Garden). Have you seen all of the 17 special gardens and collections?
They're called "living museums" because that's what they are. Living museums. And especially when they attract pollinators!
That's a question we're often asked and now we have an answer: Saturday, Oct. 7.
World-class bee garden designer and pollinator advocate Kate Frey, co-author of The Bee-Friendly Garden" (with UC San Francisco professor Gretchen LeBuhn), is inviting folks to join her to "see the principles and practices of the American Garden School expressed and demonstrated" in her unique pollinator garden in Hopland, inland Mendocino County.
A workshop from 9:30 a.m. to 10:30 a.m. will cover design, site preparation, building health soil, weed control, bees and wildlife in the garden, plant care, and will look at some recommended plant varieties. It will end with an irrigation system demonstration. The cost is $35 for the workshop.
If you want to attend the garden tour, it's from 10:30 a.m. to 2 p.m. The cost is $10, and participants are invited to bring their lunch.
Worldwide, there are 20,000 species of bees. Of that number, 4000 are found in the United States, and 1600 of them in California. A good many of them are found in the UC Berkeley Urban Gardens (see UC Berkeley Urban Bee Lab and in the Frey garden!
The Frey gardens include floral borders, a vegetable garden, unique rustic structures and whimsical art (the work and/or collection of husband Ben), a chicken palace and more. With the Swiss chalet home, this is straight out of a storybook! Indeed, visitors call it an "instant sanctuary," says Kate. They marvel at the beauty, the color, and the paths just begging to be explored. A feast for the eyes; serenity for the soul.
You can register on the American Garden School site. Directions are posted online.
If want to beautify your yard, attract pollinators, and save money at the same time, then you'll want to attend the UC Davis Arboretum Plant Sale on Saturday, Nov. 5. It's the final clearance sale of the season, and it will take place from 9 a.m. to 1 p.m. at the Aboretum Teaching Nursery on Garrod Drive, UC Davis campus.
Every plant will be marked down at least 20 percent, officials said. See list of plants here. Members save 10 percent and you can join at the door.
Taylor Lewis, UC Davis Arboretum and Public Garden nursery manager, says that autumn, with its shorter days and cooler temperatures, is "the best time of year for new planting whether you are renovating a lawn area or adding new plants to a mature landscape."
He and Ellen Zagory, director of public horticulture for the UC Davis Arboretum and Public Garden, list five reasons why plant establishment is much easier now.
- Less water use – Thanks to recent rains the soil moisture can be kept constant with less irrigation.
- Softer soil – The soil is softer now so it's easier to dig holes!
- Fewer weeds – Unwanted plant life is less prolific thanks to less sun and cooler temperatures.
- Less stress – Cooler temperatures also are less stressful to new plants.
- Hearty roots – When the air temperature is cooler than the soil temperature, plants put more energy into root growth without new top growth, which results in heartier root systems and stronger plants overall.
Zagory points out: “There isn't going to be much growth above ground where you can see it, but just wait . . . come spring your plants will show you how happy they are you planted in fall!”
Many plants at the Nov. 5th sale are geared for pollinators. Some of pollinators' favorite foods include lavender, salvia, catmint, aster, butterfly bush, lantana, borage, salvia, sunflowers, blanket flower, cone flowers, and penstemon. And many more!
Want to attract butterflies? Consider not only the nectar-producing plants but their host plants. For example, monarchs lay their eggs only on their host plant, milkweed (genus Asclepias), the only plant the caterpillars will eat.
A few other host plants of butterflies:
- Gulf Fritillaries: Passion flower vine (genus Passiflora)
- Anise swallowtails: Sweet fennel (genus Foeniculum)
- Checkered skippers: Mallow (genus Malva)
- Western tiger swallowtails: Cottonwood and aspen cottonwood and aspen (Populus), willows (Salix), wild cherry (Prunus), and ash (Fraxinus).
- Pipevine swallowtail: Dutchmen's pipe or pipevine
The website of Art Shapiro, UC Davis distinguished professor of evolution and ecology, offers a wealth of information on California butterflies. He's been studying the butterfly populations of Central California for more than four decades.
Calflora is the go-to site for a database of California non-native and native plants, invasive plants and rare plants.
The California Native Plant Society website encourage us to plant native plants.
The UC Berkeley Urban Bee Lab website recommends what to plant for native bees.
Books? Yes. Two of the most recently published:
California Bees and Blooms, a Guide for Gardeners and Naturalists is the work of UC-affiliated authors Gordon Frankie, Robbin Thorp, Barbara Ertter and Rollin Coville.
The Bee-Friendly Garden: Design an Abundant, Flower-Filled Yard that Nurtures Bees and Supports Biodiversity, by award-winning garden designerKate Frey and bee expert Gretchen LeBuhn of San Francisco State University, will guide you in selecting bee plants and designing your garden.
The two-year global assessment by the Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services (IPBES) lamented the decline in pollinators due to such human-driven factors as habitat loss, pesticides, and malnutrition. These and other culprits, including pests, invasive species and climate change, can mean extinction of many species.
Major news organizations quickly sought input from experts, including two UC Davis entomologists: native pollinator specialist Robbin Thorp, distinguished emeritus professor of entomology, who was interviewed by KGO Radio, San Francisco, and pollination ecologist Neal Williams, associate professor of entomology, who provided comments to The Washington Post.
It's not only the pollinators that are under siege. So are "the livelihoods and hundreds of billions of dollars worth of food supplies," according to the Feb. 26 IPBES report.
The assessment, "Thematic Assessment of Pollinators, Pollination and Food Production," is the first issued by the four-year-old IPBES, which spans 124 member nations. Seventy-seven experts participated, drawing information from 3000 scientific papers.
"Pollinators are important contributors to world food production and nutritional security," said Vera Lucia Imperatriz-Fonseca, Ph.D., co-chair of the assessment and senior professor at the University of São Paulo. "Their health is directly linked to our own well-being."
Numbers released by IPBES help tell the story:
- 20,000 – Number of species of wild bees. There are also some species of butterflies, moths, wasps, beetles, birds, bats and other vertebrates that contribute to pollination.
- 75 Percent – Percentage of the world's food crops that depend at least in part on pollination.
- 235 billion to $577 billion – Annual value of global crops directly affected by pollinators.
- 300 Percent – Increase in volume of agricultural production dependent on animal pollination in the past 50 years.
- Almost 90 Percent – Percentage of wild flowering plants that depend to some extent on animal pollination.
- 1.6 million tons – Annual honey production from the western honeybee.
- 16.5 Percent – Percentage of vertebrate pollinators threatened with extinction globally.
- 40 Percent (plus) – Percentage of invertebrate pollinator species – particularly bees and butterflies – facing extinction.
"In addition to food crops, pollinators contribute to crops that provide biofuels (e.g. canola and palm oils), fibers (e.g cotton), medicines, forage for livestock, and construction materials. Some species also provide materials such as beeswax for candles and musical instruments, and arts and crafts," IPBES related.
The report indicated that pesticides, pests and diseases pose a special threat to managed bees "but the risk can be reduced through better disease detection and management, and regulations relating to trade and movement of bees."
Pollinators need to be protected, the report emphasized. We can help safeguard our pollinators by:
- Maintaining or creating greater diversity of pollinator habitats in agricultural and urban landscapes;
- Supporting traditional practices that manage habitat patchiness, crop rotation, and coproduction between science and indigenous local knowledge;
- Education and exchange of knowledge among farmers, scientists, industry, communities, and the general public;
- Decreasing exposure of pollinators to pesticides by reducing their usage, seeking alternative forms of pest control, and adopting a range of specific application practices, including technologies to reduce pesticide drift; and
- Improving managed bee husbandry for pathogen control, coupled with better regulation of trade and use of commercial pollinators
- A high diversity of wild pollinators contributes to increased stability in pollination, even when managed bees are present in high numbers.
- Crop yields depend on both wild and managed species.
- The western honey bee is the most widespread managed pollinator in the world, producing an estimated 1.6 million tons of honey annually.
- The number of beehives has increased globally over the past 50 years, but a decrease in hives has occurred in many European and North American countries.
- Climate change has led to changes in the distribution of many pollinating bumblebees and butterflies and the plants that depend upon them
Neal Williams explained to The Washington Post in an email: "Hospitable landscapes are ones where there are suitable nesting habitats for diverse pollinator species, and where consistent forage resources are accessible (within the flight range) of the bees throughout their flight seasons."
Robbin Thorp told KGO that "through agricultural intensification, we have a lost a lot of habitat for native pollinators." He advocated more nesting habitat for bees. And, he said, "we need to be cautious whenever we apply pesticides" because pesticides are designed to kill insects, and bees are insects.
Honey bees, Thorp said, are just one species of about 20,000 bees in the world. "Most native bees are solitary bees that nest in the ground. They don't have a queen, they don't make honey, but they are very important in our environment."
Protecting our pollinators is crucial. They are, as IPBES, said, "economically, socially and culturally important."
The honey bee guru continues to answer a range of questions. The latest concerns the effect of marijuana growing sites on honey bees.
We thought we'd share his answer, which deals with honey bees, pollinators, Cannabis, pesticides, and what could happen to beekeepers who stumble upon a pot farm.
The question: "What is the effect, good or bad, that marijuana plants and marijuana grow sites have on the honey bee? From what I understand, these grow sites are using chemicals to control pests year round. In some cases, I hear that marijuana growers are importing chemicals from Mexico that are stronger and work better to control pest."
Mussen answered the question succinctly and openly.
"As you might guess, since marijuana is still considered an illegal plant to grow by the federal government," he replied, "it is no surprise that there are no pesticides registered for use on the 'crop.' Some states are trying hard to build a list of acceptable products, but here is the problem. So far we have registered products based on contact and oral toxicities to mammals. We have only run inhalation toxicities on a few very potent and stinky products (fumigants). You can get up to 10X the dose of a chemical, from the same amount of plant mass, if you smoke it versus eating it.
"There are quite a number of websites dedicated to pot growing. When pest control becomes the topic, most sites suggest mechanical methods or use of products allowed in organic agriculture. However, those organic pesticides have not been checked for inhalation effects, either."
"Thus, practically any pesticide that is used will be illegal. Given that, growers are apt to determine which materials work best on the pest at hand on other crops, acquire those materials, and use them. The regulators know this, and in states where marijuana currently is legal, the states are testing some of the products on the shelves to see what pesticides are in them. The samples have been found to be pretty clean, for the most part."
Mussen acknowledged that blooming hemp plants are attractive to many pollinators. "I have no idea what the pollen and nectar might do to them when the bees consume it. We can provide a pretty good idea of what will happen when pesticide products used on other crops are applied to the bloom (at agricultural rates), but since nothing is registered, there is no way of guessing what might be used. For the standard fee of just under $400, we can send a sample of the bees or pollen to the USDA AMS pesticide residue detection lab in Gastonia, N.C., and they can tell us the residues. Butthat doesn't help us much in terms of regulatory assistance.
"Pot growers probably won't care if they repel or kill visiting bees," Mussen speculated. "Pollinated blossoms become senescent too quickly, and do not produce the maximum amount of important resins if they are pollinated early in their cycle."
"Up to this time, I have not heard of beekeepers reporting damage from pesticides applied to marijuana, but it is likely to happen before long. Beekeepers are more worried about being shot if they accidentally get too close to a pot farm."