Posts Tagged: pollinators
With a little care and planning, anyone can make their little corner of the earth safe and friendly for bees.
UC Master Gardener volunteer Clare Bhakta of San Joaquin County shared bee-friendly strategies during a community workshop in August, extending the reach of research information developed by UC Agriculture and Natural Resources.
"Lure bees in," Bhakta said. "If you make it comfy, they will come."
Bhakta is a newly minted Master Gardener, having graduated in June from the intensive training program presented by UC advisors and specialists. She is part of the San Joaquin County MG speakers bureau; the "Buzz about Bees" was her inaugural engagement.
"We want bees in our gardens," Bhakta said. "Ninety percent of flowering plants and 75 percent of human crops depend on pollinators, including bees. Bee pollination makes about $15 billion in human food in the United States each year."
About 1,600 species of bees are found in California, many of them natives. Most of the bee species live independently, occupying holes in trees trunks or branches, or in the ground. Their sizes range from inch-long metallic black bumble bees to tiny sweat bees 3 millimeters in length. These species rarely sting since they don't have hives to protect.
California's most recognizable bee is the European honeybee, imported from the Old Country by settlers in the 1600s. The insects serve as efficient pollinators and produce more honey than they can use themselves - offering humans an abundance of natural golden sweetener with antioxidants, vitamins and minerals.
Bees work hard to produce honey. It takes 2 million flower visits - about 55,000 flight miles - to make a pound of honey. An individual worker bee lives just six weeks and produces about one-twelfth of a teaspoon of honey in her lifetime.
Sharon Butler, president of the Ripon Community Garden, attended the free workshop. The 2.5-acre garden at the corner of Vera and Doak avenues has dozens of raised garden plots. The community just added several bee hives. Butler asked at the workshop about an unexplained phenomenon in their first honey harvest.
"A couple of racks had dark spots with honey that had a cinnamon taste," she said.
Bhatka said the variation was probably the result of nectar from different plants.
"I wish I knew what plant it is, I'd plant a lot more," Butler said.
Creating a bee friendly garden may go against the grain for tidy gardeners. Bees don't prefer the well-trimmed plants and homogeneous color scheme of a formal outdoor space.
"Bees love herbs," Bhakta said. "I let my sage go crazy this year and I couldn't believe how tall they got."
For best results, don't over garden. Follow these five tips from the UC Master Gardener program:
- Rather than cover all soil with mulch, leave open areas for ground nesting bees.
- Keep a few dead tree stumps or branches. Particularly if it has holes, it makes an ideal nesting site for solitary bees.
- Let plants "go to seed," even when they begin to look overgrown and leggy.
- Provide a shallow water source. Filling it with pebbles or marbles allows the bees access to the water.
- Avoid using pesticides. Visit the UC Integeted Pest Management website for environmentally sound methods of controlling pests and weeds.
Bees are the most important pollinators of California agriculture — helping farmers grow field crops, fruits, nuts, and vegetables. Honey bees receive most of the credit for crop pollination, but many other kinds of bees play an important role as well. There are 1600 species of bees in California! Take time during Pollinator Week to learn about the different kinds of bees and what you can do to help them flourish.
Why should I care about other kinds of bees?
Bees other than honey bees contribute significantly to crop pollination. For example, alfalfa pollination by alfalfa leafcutter bees is worth $7 billion per year in the United States. Other bees can also boost the result of honey bee pollination — in almond orchards, honey bees are more effective when orchard mason bees are present. The more bee species, the merrier the harvest.
While growers often rent honey bee colonies to pollinate their crops, some wild bees pollinate certain crops even better than honey bees do. For instance, bumble bees are more effective pollinators of tomato because they do something honey bees do not: they shake pollen out of flowers with a technique known as buzz pollination. Likewise, native squash bees are better pollinators of cucurbits — unlike honey bees, they start work earlier in the day, and males even sleep in flowers overnight.
How can I help honey bees and other bees?
When it comes to land management and pest management practices, some bees need more accommodations than others. That's why it is important to know what bees are present in your area and important to your crop, and plan for their needs. Use this bee monitoring guide to identify bees present on your farm.
You can help all kinds of bees by using integrated pest management (IPM). This means using nonchemical pest management methods (cultural, mechanical and biological control), monitoring for pests to determine whether a pesticide is needed, and choosing pesticides that are less toxic to bees whenever possible. Check out the UC IPM Bee Precaution Pesticide Ratings to learn about the risks different pesticides pose to honey bees and other bees, and follow the Best Management Practices To Protect Bees From Pesticides.
Bees also need plenty of food to stay healthy and abundant. Plant flowers that provide nectar and pollen throughout the year. See the planting resources below to find out which plants provide year-round food for specific types of bees.
Like honey bees, native bees need nesting areas to thrive. Bumble bees, squash bees, and other bees nest underground. Ground-nesting bees may require modified tilling practices (such as tilling fields no more than 6 inches deep for squash bees) or no-till management to survive. For above-ground nesters, like carpenter bees and mason bees, consider planting hedgerows or placing tunnel-filled wooden blocks around the field. See the habitat resources below for more information about native bee nesting in agricultural areas.
Bee habitat resources
- Habitat for Bees and Beneficials
- Managing Wild Bees for Crop Pollination
- Native Bee Nest Locations in Agricultural Landscapes
- Farming for Bees: Guidelines for Providing Native Bee Habitat on Farms
- Hedgerow Planting for Pollinators: Central Valley, Central Coast, Southern California
- Conservation Cover for Pollinators: Central Valley, Central Coast, Southern California
- The Integrated Crop Pollination Project: Tools for Growers
- Insect Pollinated Crops, Insect Pollinators and U.S. Agriculture: Trend Analysis of Aggregate Data for the Period 1992–2009.
- Native bees are a rich natural resource in urban California gardens. (PDF)
- Honey bees are more effective at pollinating almonds when other species of bees are present.
“Fall, with its cooler temperatures, shorter days, and imminent rainfall, is the best time to plant a bee garden in California. Much of the plants' growth at this time will be in the roots rather than the vegetative growth, and that gives new plants an advantage when temperatures warm up and the soil dries in the spring. Fall and winter are usually the wet seasons in California, and a bee garden will benefit from the natural pattern of rainfall that helps plants get established,” according to California Bee-Friendly Garden Recipes (Pawelek et al. 2015)
With fall being the perfect time for planting consider making your home landscape bee-friendly and follow UC Agriculture and Natural Resources' California Bee-Friendly Garden Recipes - 12 rules of thumb for creating a bee-friendly home landscape:
- Learn the seasonality of plants and bees.
Bees need both pollen and nectar resources from plants all year long. Sugary nectar provides energy for adult bees, and protein-rich pollen is used to feed their young. Plant not only a variety of plants (to ensure both pollen and nectar resources) but also make sure that they bloom at different times throughout the year, with the most active times of bees in garden running from February to October.
- Provide a diversity of floral hosts.
A large variety of plants in a garden attracts a more diverse bee population. UC ANR researchers recommend planning a minimum of 20 different plant types to provide plenty of nectar and pollen sources for bees. If space or resources don't allow, consider plants that provide both nectar and pollen resources such as seaside daisy (Erigeron glaucus), blanketflower (Gaillardia x grandiflora), thyme (Thymus vulgaris), and coneflower (Echinacea purpurea).
- Give structure to the garden.
When planning your garden arrange plants so it is easy to observe the bees that are visiting your landscape. Place taller plants or shrubs in the back and smaller or shorter plants in the front. Or you can plant in the shape of an island to allow viewing from all sides.
- Plant in the sun.
Typically bees prefer flowers in the sunshine over the shade. Monitor the amount and location of sun in your home landscape and plant sun-loving bee-attractive plants in the sunniest section of your yard.
- Plant shrubs, perennials and annuals in patches.
Most bees will visit one type or a few types of flowers each time they forage, an abundance of the same flower variety allows for more efficient foraging for bees. The California Bee-Friendly Garden Recipes publication recommends a 3.5 ft x 3.5 ft flower patch of the same variety.
- Don't forget to seed annuals.
Plant seeds for spring blooming annuals and bulbs in the fall and take advantage of the winter rains and provide beautiful flowers in the spring. Great options include sunflowers (Helianthus annuus), Mexican sunflower (Tithonia diversifolia), California poppy (Eschscholzia californica), and zinnia (Zinnia elegans).
- Maintain flowers.
Prolong a plant's blooming season by dead-heading. As soon as flowers begin to fade, wither and brown, pinch or cut-off the flower stem below the flower or right above the first set of healthy leaves. This allows the plant to continue to invest in producing more blooms and not seeds.
- Create a watering regimen.
Regular watering of plants during blooming season allows plants to produce more flowers for a longer period of time. If a plant is water stressed it won't produce new flowers and nectar and pollen production declines. Consider plants that thrive in California's dry Mediterranean climate, UC Berkeley's Urban Bee Lab offers a list of the best bee plants with a large selection of California native options.
- Do not use pesticides!
Applying pesticides to your home landscape can kill beneficial insects and bugs visiting your garden, including bees. Consider using integrated pest management practices that are natural or organic methods like hand-picking, spraying with water or natural insecticides. Contact your local UCCE Master Gardener Program to learn more about integrated pest management.
- Consider plant climate zones.
Consider right plant, right place when selecting plants for your home landscape. Most gardening books, websites, plant labels and seed packets refer to a plants hardiness zone, climate zone or growing zone. Become familiar with the climate or microclimate in your area, the USDA Plant Hardiness Map and the Sunset Zone Map are a great starting guide for determining what plants will thrive in your garden space.
- Provide homes for nesting bees.
A bee-friendly garden provides cover and a safe place for bees to raise young. Most bee habitats are either in the ground or in pre-existing cavities. Provide a nesting home for bees in your garden by leaving a small section of your landscape unmulched for ground-nesting bees. Nesting blocks, drilled holes in untreated wood or “bee-condos” can be offered to bees that prefer a pre-existing cavity habitat.
- Provide nesting materials, including a water source.
Bees build their nests with mud, plant leaves and resins. Bees require a water source to not only drink but also to make mud for nest building. Fill a shallow water dish or birdbath to your garden, add small rocks or a floating cork for bees to rest and to prevent drowning.
Learn more with UC ANR and the UC Master Gardener Program
Interested in learning more about how to grow a buzzing bee-friendly garden? The UC Master Gardener Program has University trained volunteers who are eager to help. Volunteers are available to answer questions about preparing your soil, plant selection, pest management, and more. With local programs based in more than 50 counties across California and thousands of workshops a year there is sure to be an event or class near you. Visit our website to find your local UC Master Gardener Program, mg.ucanr.edu.
Pawelek, Jaime C., Frankie, Gordon W., Frey, Kate, Leon Guerrero, Sara, and Schindler, Mary. 2015. “California Bee Friendly Garden Recipes.” ANR Publication 8518, http://anrcatalog.ucanr.edu/pdf/8518.pdf
Ponder, Marissa, Frankie, Gordon W., Elkins, Rachel, Frey, Kate, Coville, Rollin, Schindler, Mary, Pawelek, Jaime, and Shaffer, Carolyn. 2013. “How to Attract and Maintain Pollinators in your Garden.” ANR Publication 8518, http://anrcatalog.ucanr.edu/pdf/8498.pdf
fundraiser for undergraduate education, and Allen-Diaz, who has endured bee stings in the past, is willing to take the risk for this important cause. She'll have the help of a noted bee wrangler, UC Davis emeritus professor of entomology Norm Gary. Gary has performed such unlikely stunts as playing the clarinet while covered with honeybees. He will apply a synthetic pheromone to Allen-Diaz's hands to attract the bees, which he says are unlikely to sting unless provoked.
“I'll be holding a precious resource in my hands, one that is essential to life on earth,” says Allen-Diaz. “I'll be placing my hands in Norm's hands to raise awareness about the value of honeybees.”
While raising money for education is certainly a worthy goal, as Allen-Diaz says, the event also draws attention to the plight of our most important agricultural pollinator. In 2006, a number of beekeepers in the Western U.S. noticed their hives had lost 30 to 70 percent of their worker bees. The phenomenon, now known as colony collapse disorder (CCD), is still not fully understood, though a number of factors are believed to be involved. They include habitat loss or degradation and fragmentation, poor nutrition, certain bee management and agricultural practices, natural and chemical toxins, diseases, and parasites. Any one of these factors can affect the insects' ability to combat any of the others. Isolating a single cause, if there is one, has proved elusive.
Many of the fruits and vegetables on the tables of the world are pollinated by insects, particularly bees, and if they were to disappear, our sources of plant food would be restricted to grains and not too much else. It's no wonder CCD is such a concern (for example, see the United Nations Environmental Program 2010 report on Global Bee Colony Disorder and USDA, Honey Bees and Colony Collapse Disorder.
Losey and Vaughn (2006) estimate the value to the U.S. economy of native insects (not honeybees, which are native to Europe) to be at least $57 billion.
As human population grows and becomes more urban, and as habitats get more fragmented, it is no longer adequate to focus conservation efforts merely in non-urban, non-working landscapes.
“We need to figure out how to accommodate as many native species as possible in these kinds of places,” says Patrick Huber of the City of Davis Open Space and Habitat Commission, which has adopted pollinator habitat enhancement as a working goal. The Commission is working to compile a GIS dataset of known big patches of habitat in Davis, in order map pollinator resources around town.
Huber is a geographer in the Landscape Analysis and Systems Research lab at UC Davis, where he focuses on spatial scale in conservation planning. He is working on a tool to help match gardeners with plants that will grow well in their regions, that are locally available, and that provide a network of resources for pollinators throughout the urban landscape and on into the agricultural landscape. For the moment this project is being piloted in Davis, but the hope is to expand it to other communities, tying in resources such as CalFlora.
California Center for Urban Horticulture, Your Sustainable Backyard: Pollinator Gardening, focused on this very issue: what gardeners can do to help pollinators, many of which are bees. (Of 19,500 known bee species in the world, 4,000 can be found in North America and 1,600 in California. There are at least 300 species of bee in Yolo County alone.) Urban gardeners can help pollinators by:
- Planning for succession blooming (in the Central Valley, that means late winter through fall)
- Putting plants in clumps at least 4 feet long if possible (honeybees, especially, like to specialize)
- Putting in plants that provide both nectar and pollen (nectar is fuel for adult bees, pollen is protein for the young)
- Using native plants where possible; they're drought tolerant and have what our native bees need
- Avoiding most-toxic pesticides and herbicides
- Providing a clean source of water (a slow-dripping tap on a sloped surface is ideal; bees like to drink from very shallow sources)
- Providing cavity nest holes in wood for carpenter and other bees
- Leaving some areas of gardens unmulched for ground-nesting bees
There are ways the agricultural landscape can be made more hospitable, too. Neal Williams, professor of entomology at UC Davis, has been working on a project to install 600- to 800-meter plots of flowering plants alongside large fields as resources for pollinators. This has moved out of the trial phase into test plots in coastal and foothill areas as well as in the Central Valley.
Meanwhile, we can all help count our pollinators on May 8, the Day of Science and Service to celebrate 100 years of Cooperative Extension in California. We'll be conducting our own pollinator count here outside the ANR building in Davis: join us, or let us know about yours!
Many thanks to Kathy Keatley Garvey for use of her photos.
With warm weather and mostly dry skies, some California farmers are prepping their fields for spring planting. On many fields used to grow squash and pumpkins, native squash bees (Peponapis pruinosa), valuable pollinators for squash growers, are nesting in the soil, waiting for spring emergence. With over ten thousand acres of squash and pumpkins grown in California in 2011, the success of pollination covers a lot of ground.
are showing that native bees may be more productive pollinators than honey bees, and that in some cases, the presence of native bees can boost the pollinating potential of commercially produced honey bees. But native bee populations face threats that are not yet fully understood.
For native bee researcher Katharina Ullmann, understanding how these bees will be impacted by the upcoming tillage and other farming practices are big questions that can help farmers make decisions that protect native bee populations in their fields and maximize the benefit farmers see from pollinators. Ullmann was recently awarded a grant from Western SARE (Sustainable Agriculture Research and Education) and the National Science Foundation to fund her doctoral research on how crop rotations and tillage practices affect native squash bee populations.
Bee Biology lab run by Neal Williams, assistant professor of Entomology at UC Davis and a contributing author to recent studies on the benefits of native bees. Too, Ullmann serves on the Advisory Board to the Agricultural Sustainability Institute at UC Davis, linking field-level entomology to broader sustainability research.
Native squash bees nest 5 to 20 inches deep in the soil, and plowing or disking often disturbs soil as much as 20 inches deep, potentially damaging bee nests. Conservation tillage and no-till practices are increasingly seen as ways to lower fuel use and on-farm emissions from nitrogen and carbon dioxide, as well as decrease water runoff. Protecting native bee populations could potentially be an additional co-benefit to these methods.
I think about native bees as an insurance policy and potentially a yield increaser,” says Ullmann. “Honey bees are important; they’re always going to be important. But it can be beneficial for growers to know if they have crop-pollinating native bees flying around if, for example, honey bee prices spike or if it’s hard for a grower to get the number of honey bee colonies he or she needs.” Too, with new studies highlighting the productivity of native bees (in some cases doubling fruit set compared to honey bees), there is growing incentive to protect nesting grounds.
The results of Ullmann’s tillage study, in coordination with a parallel study on the effect of crop rotation on bee populations, will be turned into a user-friendly web tool for farmers to assess which combination of in-field practices will likely be best for fostering bee populations. “In creating these models of tillage and crop rotation practices, we’re hoping to help farmers find the synergy between different farming practices that yield the greatest benefits,” says Ullmann.
“Not all farmers will change tillage or crop rotation practices just because of bees, but maybe this is another piece of information that farmers can use to make informed management decisions. “Ultimately,” says Ullmann, “my goal is to provide farmers with that opportunity.”
Looking for squash bees on your farm or in your garden? They look similar to honey bees but with fuzzier legs that lift dry pollen from squash blossoms, and male bees have a yellow spot on their face that resembles a nose. But perhaps the easiest way to identify them — gently squeeze a closed squash blossom and wait to hear a buzz. The bee inside is likely a native squash bee, resting up in preparation for more work.