In the News
've been interested in surface temperatures of various living and non-living surfaces in our inland Southern California cities with increasingly hot urban heat islands for some time. Results are in! Use of dark asphalt,
What can you do?
Take care of your trees, shrubs, groundcovers, and lawns, which cool the environment substantially. In the same experiment, the coolest scenario was the surface temperature of a lawn in the shade of a mature tree. Remember that, through transpiration, living plants cool the environment while non-living surfaces do not.
If you're tired of your high maintenance lawn, think about alternative groundcovers that have similar effects (see suggestions below). While cool season lawns like tall fescue and ryes are high water-requiring plants, warm season lawns like Bermuda, zoysia, and buffalograss are more drought-resistant. Our studies have found that it's not the lawns and groundcovers that waste the water, it's the inefficiency of most sprinkler systems, coupled with not applying the right amount of water at the right time. This holds true for even the most drought-resistant native and non-native groundcovers irrigated via sprinklers, as well.
Plant drought-tolerant groundcovers
There are dozens of groundcover species that are both drought and heat-tolerant suitable for California gardens.
Here are just two examples:
Creeping thyme (Thymus serpyhllum) They are both drought resistant and do well in the heat. Fragrant flowers add a special touch to a meandering path to a secret backyard garden (below left).
Rosemary (Rosmarinus prostratus) Some rosemary species are low-growing groundcovers. It is great for rock gardens, growing to only 6 inches tall. It produces purple flowers in the summer and attracts pollinators and can be used for culinary purpose (below right).
trees cool urban heat islands
• Your trees come first! If there just isn't enough water to go around, your lawn and flowers should be sacrificed instead. Trees are our most valuable landscape resource and take years to maximize their benefits (shade, cooling, habitat/ecosystem enhancement, carbon dioxide storage, etc.).
• Spread and maintain 2-4” of mulch around garden plants and trees (3-4” for wood chips, 2” for pebbles, decomposed gravel, etc.) keeping it a few inches away from tree trunks.
• Water early in the morning when soil evaporation is minimal.
• Control weeds. They compete with other plants for water.
• Avoid fertilizing. Nitrogen increases growth and the need for more water.
• Don't plant new plants during the summer when temperatures are highest. Even drought-resistant native and non-native plants need regular watering their first season.
If you have seen a butterfly native to Orange County fluttering its wings along a flowerbed searching for nectar, chances are the same species has been found in the garden of UC Master Gardener volunteer Heather Hafner. But that wasn't always the case. For more than two decades, Hafner played professional volleyball on the sunny beaches of Southern California. If it wasn't for a related sports injury, she might have never been introduced to the adventure of attracting butterflies and pollinators into her garden.
While recovering from surgery, Hafner decided to refresh her landscape and visited a local nursery. Slowly shuffling down the aisle and waiting for help she overhead an employee at the nursery showing a customer a monarch egg on the underside of a leaf. Captivated by the possibility of taking home a butterfly for her garden, she optimistically purchased the plant with a monarch egg and patiently waited.
After learning about the many challenges monarchs face to survive, Hafner quickly began to explore how to support monarchs and other butterflies in her garden. She watched videos, read books, and attended workshops and events with the UC Master Gardener Program of Orange County. Hafner was determined to learn everything she could about what butterflies are native to her area and how to build a habitat to support them. Then she got to work. Her goal is now to provide a larval host plant for as many local butterflies as possible.
Her small garden in Irvine, Calif., offers a food source for more than 30 kinds of butterflies. "If I can't eat it, or it's not food for a butterfly – then it doesn't go into my garden," says Hafner, "For me to give up real estate in my garden, I want to know that it is serving a purpose and supporting local butterflies and other pollinators."
She has planted many host plants and trees for almost every type of butterfly found in Orange County. Some of her plants include pipevine, passionvine, hollyleaf cherry, fennel, rue, popcorn cassia, figwort, monkeyflower, Snapdragon, lupin, licorice, California lilac, penstemon, puellia, California buckwheat, bladderpod, and deerweed. She specializes in milkweed (Asclepias) and propagates 12 kinds from seed with differing soil, soil temperature, stratification, and watering requirements. Like any gardening journey, it has been a series of wins and losses.
Her passion for butterflies brought her to the UC Master Gardener Program in search of native plant propagation techniques. Still, she also knew she wanted to make a larger impact in her community and encourage others to help build pollinator habitat in their landscapes. Hafner was accepted into the UC Master Gardener Program of Orange County and completed her training in 2019.
As a UC Master Gardener volunteer, Hafner first focused a large part of her volunteer efforts on the propagation, orchard and youth garden teams. Today, she serves as the co-lead of the youth demonstration garden at the South Coast Research and Extension Center (REC), where they are installing a monarch conservation exhibit with the three native milkweeds and some non-natives to show how non-natives can be responsibly used (cut them back when natives go dormant). Her goal is to help conserve the Western monarch butterfly, which is dwindling in numbers.
She quickly fell in love with the beauty of a diversified garden. "I love monarchs … but my garden wouldn't be the same without the diversity of the other butterflies and pollinators," says Hafner. While not all butterflies arrive at the same time, they are all welcome in her garden.
For the past year, Hafner has expanded her volunteer efforts and used skills from her professional career as a teambuilding facilitator to help improve the diversity of the Orange County program's volunteers. Being a trained facilitator helped her recognize who was missing or underrepresented in the program, which is primarily white and female. She ran a comprehensive outreach campaign to help recruit new volunteers that included geographical, ethnic, economic and chronological age diversity. She called newspapers and community centers in the corners of Orange County to recruit volunteers who were more representative of the people the county serves. Her recruiting efforts and strategy resulted in the county's largest and most inclusive class (58 trainees).
Hafner was most proud of the fact that the program in Orange County now has members who speak 10 languages: Vietnamese, Mandarin, Korean, Spanish, Urdu/Hindi, Portuguese, German, French, Italian and Farsi. These new UC Master Gardener volunteers will create presentations in their native language for outreach into their communities. "I think it's important that UC Master Gardener volunteers represent the community we live in," says Hafner, "and I think this year we delivered on that."
2021 Gardeners with Heart
The UC Master Gardener Program is proud to recognize Heather Hafner as a 2021 Gardener with Heart for the impact her volunteer work is making in her community. "Without Heather's incredible contribution, our first virtual UC Master Gardener training class simply could not have happened," says program coordinator Randy Musser, "and our program in the future will benefit greatly because of its new, more diverse members."
Gardeners with Heart are nominated by local county leadership for their stewardship of the UC Master Gardener Program during the pandemic period, their diversity equity and inclusion leadership, and their digital superstardom.
Instructions for making homemade mixtures to control pests are easy to find online and in social media, and it's tempting to make your own home remedy when pests invade. Doing so may seem like a natural, organic, and non-chemical solution, but did you know that what you are mixing is considered a pesticide? A pesticide is any mixture used to kill, destroy, repel, or mitigate a pest.
Pesticide mixtures of household ingredients like dish soap, garlic, and vinegar (Figure 1) may seem harmless and safer than storebought formulated pesticides, but they can actually pose unrealized risks.
What is the Concern with Homemade Pesticides?
While ingredients in home remedies are items we might eat or use in the kitchen, the mixture of them is not tested for
For example, some online sources describe making a homemade insecticide from the tobacco leaves found in cigarettes and tout it as “natural” or “organic.” While cigarettes are readily available for purchase, the resulting concoction (a pesticide) made from tobacco is extremely concentrated and highly poisonous to humans and pets. There are many additives used in producing products such as cigarettes, soaps, or detergents and these ingredients are not always known to the consumer.
Another concern is the potential hazard created during the mixing and making of home remedies. Even while natural, some ingredients become more toxic during the process of cooking the mixture, which may concentrate the ingredients and increase risks of harmful health side effects due to inhalation of fumes or contact with skin.
No Instructions for Use
Commercially available pesticides (Figure 2) are required by law to have a label with instructions on use, mixing, storage, and first aid. Home remedies don't have instructions for specific dilution or use rates, nor do they identify how often mixtures should be applied. Home remedies also contain no guidance about wearing protective equipment like gloves or how to properly store the mixture.
Homemade mixtures are stored in containers that are either not labeled with what's inside or lack the required label information registered pesticides contain. Each year, poison control centers report poisonings of children and adults from drinking pesticides that have been stored in food or drink containers. Without a label and knowledge of how a mixture can affect people when exposed, first aid information isn't available. To prevent accidental poisoning, pesticides should never be mixed or stored in food or drink containers even if the container is marked.
Are home remedies effective?
Because homemade pesticides vary greatly in their makeup and are not tested through rigorous research studies, there is no data to support whether they consistently control targeted pests. Unlike commercial pesticides that must show their efficacy data before being registered, homemade remedies lack scientific studies to show that they are effective.
Applying ineffective homemade pesticides can make pest problems worse, may not control the pest, could be harmful to the plant, or contaminate waterways. In addition, a homemade pesticide sprayed in the garden may kill the “good bugs” as well as the targeted pest insects. Many commercial pesticides are formulated to work only on specific pests or groups of pests.
Many home remedies specify using dish soap mixed with other ingredients to kill insects, plant diseases, or weeds. Dish soap, which is a powerful detergent, can injure desirable plants by stripping the waxy layer off the leaves. Commercially available insecticidal, fungicidal, and herbicidal soaps, which are registered pesticides, are highly effective against the targeted pest and will not damage plants when used correctly. These products cannot be made at home with common household ingredients.
Are home remedies legal?
The U.S. Federal Insecticide, Fungicide and Rodenticide Act (FIFRA) covers the use of homemade pesticides. According to FIFRA, in order to legally apply a material as a pesticide it must be either registered with the Environmental Protection Agency (EPA) or be exempt from registration. There is a list of active ingredients (the part of a pesticide that affects the pest) that can be used in pesticide products without requiring registration; these are called minimum risk or 25(b) products) The active ingredient list allows the use of single chemicals, like sodium lauryl sulfate (found in soap), as unregistered pesticides, but does not include commercial products like dish soap that may contain other ingredients, such as viscosity modifiers, preservatives, and pH adjusters.
Alternatives to pesticides
Many pests in the home and garden can be managed without pesticides. In a garden, grow plants suited to the environment and keep them healthy with proper irrigation and fertilization. Weeds can be controlled by hand-pulling, mulching, or weeding tools. For more information, see the UC IPM Home and Garden pages.
Please consider making a tax-deductible donation on Friday, June 4 ("Big Dig Day" or anytime!) to support the efforts of our 220 UC Cooperative Extension San Bernardino County Master Gardener volunteers.These highly trained, dedicated, and passionate volunteers help over 35,000 county residents each year grow food in home, school, and community gardens; cool urban heat islands through the proper selection and care of drought-efficient landscape plants; and, enhance their quality of life through participating in outdoor activities. Even during COVID, the Master Gardener volunteers provided education at more than 150 educational activities, adapting in-person training to online opportunities. These volunteers provide over $260,000 of services free each year!
Options for 'on the spot' donating include making a one-time gift, a recurring (monthly gift) or cherishing the memory of a loved one through a tribute gift. Donating is convenient! Simply visit http://cesanbernardino.ucanr.edu/ and click on the blue "Make a Gift UCCE San Bernardino County Master Gardener/Horticulture Fund" bar through our secure network using a credit or debit card. Your gift will be immediately acknowledged for your records. Share your support for the UCCE San Bernardino County Master Gardener program on social media by including #BigDigDay and #giveback in your posts.
Other ways to give: (information provided by Kelly Scott, major gifts officer, UC ANR)
There are a variety of planned gift options that will allow you to meet your philanthropic and financial goals. You can make a significant impact by supporting the UC Master Gardener Program through your estate plans, for instance by making a bequest. Donors may also establish income-producing gifts such as charitable gift annuities or charitable remainder trusts, which benefit them during their lifetimes with up-front income tax savings and often at a higher return. (Please contact Kelly Scott at firstname.lastname@example.org or (530) 750-1307 for more information on this option.)
Stock and Appreciated Securities
Avoid capital gains tax and claim a federal tax charitable deduction for the full appreciated value of long-term (held more than 1 year) securities (stocks, bonds, mutual fund shares). In order to qualify, gifts must be transferred directly from your brokerage account to the Regents of the University of California. (Please contact Kelly Scott at email@example.com or (530) 750-1307 for more information on this option.)
Real Estate/Personal Property
Gifts of tangible property or other assets that represent value may offer you tax benefits while also enabling you to support our program. Examples include real estate, equipment, collections, and artwork. If you have a gift of this kind. (Please contact Kelly Scott at firstname.lastname@example.org or (530) 750-1307 for more information on this option.)
Please help us spread the word and share this blog with others who have benefited from the help of a Master Gardener volunteer.
We hope you will join us on June 4!
Thank you in advance for your generosity./span>