Posts Tagged: Garden pests

The Invasion of the Voles

You really do not want voles (also called meadow mice) moving into your garden. They are larger than a house mouse or deer mouse but do not quite reach the size of an adult gopher or rat. Although it is said that they can mature to 5–8 inches long including the tail, they are most commonly on the smaller side of the range. With their charming pudgy shape, beady black eyes, small ears, soft gray/brown fur, and rather short and oddly furry tail, their appearance could be thought of as somewhat cute or endearing. That is, until you experience how quickly they can lay waste to your beloved garden.

When they are not ravaging your garden plants, these rodents spend much of their time hiding in their burrows. They are most likely to be seen during the cooler parts of the day such as dawn and dusk, when they dash from one burrow to another, or scurry from dining on your favorite plant into the safety of their burrows. The burrows have openings that are 1 ½ to 2 inches wide. There are often obvious runways from the burrows where soil is trampled down by their repeated scampering back and forth. Voles will happily burrow into both mulch and soil, and where there are dense weeds or long grasses (a favored habitat), voles will create distinctive tunnels through the vegetation.

 

Vole populations regularly go through cycles of low to high numbers. Their numbers generally peak each 3 to 6 years or so, but don't count on being able to guess when the next vole invasion will occur. These cycles are not predictable. Their numbers can increase to staggering amounts during a population explosion, soaring to as many as several thousand per acre.

If you have voles in your garden, you already know they eat a very wide variety of plants. Unlike rats and mice that are out and about wreaking havoc at night, voles are active both day and night, and year-round. Also, unlike rats and mice who have favorite foods and tend to go after sweet, ripe fruits and the most succulent vegetables, voles are not terribly picky. They will eat a wide variety of plants including zucchini, cucumber, green bean, tomato, and artichoke. Basil, dill and parsley are some herb plants that may be there one day and gone the next. Flowers such as marigolds, cosmos, yarrow, and sunflower are also part of their menu plan.

 

Voles do take an occasional break from their feeding frenzy to breed and can have 5 to 10 litters of offspring each year. They can have 3–6 young at a time. One redeeming quality is their short lifespan of just a few months to a year, and the fact that after a season of super high numbers, the population tends to go back to normal.

There are several effective control methods such as habitat modification (make the area less hospitable to them), trapping (setting many, many mouse traps), and exclusion (creating impassable barriers around your garden, your garden beds, or even individual plants).

Vole management
Habitat modification is an effective way to reduce vole damage in the landscape. Remove weeds, heavy mulch, and dense vegetative cover to reduce their food sources and expose them to predators. Voles prefer not to feed in the open so 4-foot buffer strips of open ground can help protect trees or other plants.

Because of the large numbers of voles that can be present during a population explosion, exclusion is often the most important option. Wire hardware cloth with ¼ inch or smaller mesh makes a good barrier if it is at least 12 inches tall. Make sure it surrounds the plants completely and bury it into ground 6 to 10 inches deep. Metal roof flashing, sold in hardware stores, makes a very effective barrier. It comes in rolls with varying widths. Unlike gophers, who dig deep burrows, voles usually dig down only a few inches. They are not very athletic and don't climb or jump very well like rats can, so barriers don't have to be terribly tall to be effective.

Trapping can be effective if vole numbers are low or they are in a small area, but difficult when the population is high. The key is to use many mouse traps at the same time. For detailed directions on how to place traps, see the link below.

Voles are an important part of the natural food chain. They are prey for a variety of predators including hawks, crows, owls, snakes, raccoons, bobcats, foxes, coyotes, opossums, and domestic cats. They may not keep vole populations adequately controlled near homes because of their reluctance to hunt close to homes.

There are toxic baits available, but care must be taken to ensure the safety of children, pets, and nontarget animals such as the predators listed above. See the link below for more information.

This UC IPM (integrated pest management) link is an excellent source for information on identifying and managing voles:
https://ipm.ucanr.edu/home-and-landscape/voles/pest-notes/#gsc.tab=0

This link will help you determine whether damage to your yard is due to voles, gophers or moles:
https://ucanr.edu/blogs/blogcore/postdetail.cfm?postnum=49119

Help Desk of the UC Master Gardeners of Contra Costa County (SMH)

Vole damage to root crown and lower bark of a tree. Credit: Jack Kelly Clark, UC IPM

Photo of vole damage at base of a tree

Vole damage to turf showing burrows and runways. Credit: Terrell P. Salmon, UC IPM

Photo of vole damage to turf

Hardware cloth barrier. Credit: S. Hoyer

Photo of hardware cloth protecting a plant from voles

Because they cannot climb the metal sides, your plants can be safe from voles in beds like these. Credit: S. Hoyer

Photo of metal sides protecting veggie bed from voles

Another very effective option is to add an (at least 12-inch tall) metal flashing barrier to wooden raised beds. Credit: S. Hoyer

Photo of metal flashing protecting veggie garden from voles

Lawn-pocalypse! Surviving Drought

Ah, summer! The season of sunburns, pool parties, and… lawn droughts. If your once lush, green carpet now looks like a crunchy brown doormat, you're not alone. Let's dive into why your yard is staging a dramatic death scene and what you can do to...

Bermuda grass and weeds overtaking drought stressed turf grass.

A patch of former lawn, mostly dead, with a few green weeds and Bermudagrass

Climate-Change Resources

University of California UC ANR Green Blog (Climate Change and Other Topics) https://ucanr.edu/blogs/Green/index.cfm?tagname=climate%20change (full index)

Examples:

     -  Save Trees First: Tips to Keep Them Alive Under Drought https://ucanr.edu/b/~CdD 

     - Landscaping with Fire Exposure in Mind: https://ucanr.edu/b/~G4D

     - Cities in California Inland Areas Must Make Street Tree Changes to adapt to Future Climate  https://ucanr.edu/b/~oF7

Drought, Climate Change and California Water Management Ted Grantham, UC Cooperative Extension specialist (23 minutes) https://youtu.be/dlimj75Wn9Q

Climate Variability and Change: Trends and Impacts on CA Agriculture Tapan Pathak, UC Cooperative Extension specialist (24 minutes) https://youtu.be/bIHI0yqqQJc

California Institute for Water Resources (links to blogs, talks, podcasts, water experts, etc.) https://ciwr.ucanr.edu/California_Drought_Expertise/

UC ANR Wildfire Resources (publications, videos, etc.) https://ucanr.edu/News/For_the_media/Press_kits/Wildfire/ (main website)

      -UC ANR Fire Resources and Information https://ucanr.edu/sites/fire/ (main website)

            -Preparing Home Landscaping https://ucanr.edu/sites/fire/Prepare/Landscaping/

UC ANR Free Publications https://anrcatalog.ucanr.edu/ (main website)

- Benefits of Plants to Humans and Urban Ecosystems: https://anrcatalog.ucanr.edu/pdf/8726.pdf

 -Keeping Plants Alive Under Drought and Water Restrictions (English version) https://anrcatalog.ucanr.edu/pdf/8553.pdf

  (Spanish version) https://anrcatalog.ucanr.edu/pdf/8628.pdf

-  Use of Graywater in Urban Landscapes https://anrcatalog.ucanr.edu/pdf/8536.pdf

-  Sustainable Landscaping in California https://anrcatalog.ucanr.edu/pdf/8504.pdf

 

Other (Non-UC) Climate Change Resources

Urban Forests and Climate Change. Urban forests play an important role in climate change mitigation and adaptation. Active stewardship of a community's forestry assets can strengthen local resilience to climate change while creating more sustainable and desirable places to live. https://www.fs.usda.gov/ccrc/topics/urban-forests

Examining the Viability of Planting Trees to Mitigate Climate Change (plausible at the forest level) https://climate.nasa.gov/news/2927/examining-the-viability-of-planting-trees-to-help-mitigate-climate-change/

Reports and other information resources coordinated under the auspices of the United Nations and produced through the collaboration of thousands of international scientists to provide a clear and up to date view of the current state of scientific knowledge relevant to climate change. United Nations Climate Action

Scientific reports, programs, action movements and events related to climate change. National Center for Atmospheric Research (National Science Foundation)

Find useful reports, program information and other documents resulting from federally funded research and development into the behavior of the atmosphere and related physical, biological and social systems. Search and find climate data from prehistory through to an hour ago in the world's largest climate data archive. (Formerly the "Climatic Data Center") National Centers for Environmental Information (NOAA)

Think tank providing information, analysis, policy and solution development for addressing climate change and energy issues (formerly known as the: "Pew Center on Global Climate Change"). Center for Climate & Energy Solutions (C2ES)

Mapping Resilience: A Blueprint for Thriving in the Face of Climate Disaster. The Climate Adaptation Knowledge Exchange (CAKE) was launched in July 2010 and is managed by EcoAdapt, a non-profit with a singular mission: to create a robust future in the face of climate change by bringing together diverse players to reshape planning and management in response to rapid climate change. https://www.cakex.org/documents/mapping-resilience-blueprint-thriving-face-climate-disaster

Cal-Adapt provides a way to explore peer-reviewed data that portrays how climate change might affect California at the state and local level. We make this data available through downloads, visualizations, and the Cal-Adapt API for your research, outreach, and adaptation planning needs. Cal-Adapt is a collaboration between state agency funding programs, university and private sector researchers https://cal-adapt.org/

Find reports, maps, data and other resources produced through a confederation of the research arms of 13 Federal departments and agencies that carry out research and develop and maintain capabilities that support the Nation's response to global change. Global Change (U.S. Global Change Research Program)

The Pacific Institute is a global water think tank that combines science-based thought leadership with active outreach to influence local, national, and international efforts to develop sustainable water policies. https://pacinst.org/our-approach/

Making equity real in climate adaptation and community resilience policies and programs: a guidebook. https://greenlining.org/publications/2019/making-equity-real-in-climate-adaption-and-community-resilience-policies-and-programs-a-guidebook/ 

Quarterly CA Climate Updates and CA Drought Monitor Maps (updated each Thursday) https://www.drought.gov/documents/quarterly-climate-impacts-and-outlook-western-region-june-2022

 

 

 

 

Aphids in the Garden

Aphids can be a scourge in the garden. There are over 4,000 species of aphids in the world, but fortunately only(!) about 250 species are attracted to the plants we grow in our gardens and landscapes.

Aphids are small, slow-moving insects that come in a variety of colors—green, yellow, brown, red, or black. They sometimes match the color of the plant they feed on, but not always. They have long legs and antennae, and usually have a pair of cornicles (tube-like structures) sticking out of their hind end. No other insects have cornicles. Some adult aphids have wings—this can occur when populations are high or during spring and fall—that can allow them to disperse to other plants.

Aphid reproduction is interesting. Adult females can give birth to up to 12 live offspring each day without mating. During warm weather, many aphid species can grow from newborn nymph to reproductive adult in a week. No wonder it seems like they appear overnight.

Aphids are attracted to plants on which they can feed. Plants that are actively growing are prime targets. Right now, these include plants in our winter gardens such as kale and broccoli and landscape plants such as roses, but also the many winter weeds growing abundantly in many neighborhoods.

Aphids have sucking mouth parts, somewhat like little straws. They use them to suck sap (which is a plant's sugar source). What they excrete is commonly referred to as ‘honeydew' which contains sugar and is therefore sticky. Ants are attracted to this honeydew and will actively “farm” the aphids and protect them against natural predators.

Many plants, especially trees and shrubs, can survive just fine with low to moderate numbers of leaf-feeding aphids. Damage can occur with larger populations. Yellowing leaves and stunted growth are common.

Aphids can also transmit viruses from plant to plant on many vegetable crops and ornamental plants. Symptoms can include mottled, yellow, or curled leaves, along with stunted growth.

Controlling aphids

Understanding their life cycle is key to their management. By checking plants twice a week while they are growing rapidly, you can catch infestations early. With small populations of wingless aphids, hosing them off with a strong stream of water works well. Once off the plants, aphids are unlikely to be able to return. You can also prune out the most infested parts. Make sure you also remove nearby weeds that can serve as a reservoir of new infestations.

Natural enemies are important for aphid control. Parasitic wasps lay eggs inside live aphids, causing them to turn into mummies. You can recognize these by light-colored aphid bodies with circular holes on top where the wasp has emerged. Lady beetles (especially the larvae), syrphid fly larvae, and green lacewings are voracious eaters of aphids. See this website: https://ipm.ucanr.edu/natural-enemies/

If spraying with water is not effective enough, insecticidal soaps and oils are the best choices for most situations. Oils include petroleum-based horticultural oils or plant-derived oils such as neem or canola oil. These products kill primarily by smothering the aphid, so thorough coverage of infested foliage is required. Soaps and oils kill only those aphids present on the day they are sprayed, so applications may need to be repeated. Although these products can kill some natural enemies that are present on the plant and hit by the spray, they don't leave a toxic residue.

It is easier to manage aphids earlier in an infestation than later when populations are high. Some aphids cause leaves to curl around them, protecting them from sprays and beneficial insects.

Prevention

• When you purchase new plants, inspect them carefully.
• Don't over-fertilize. Excess fertilizers, especially too much nitrogen, can stimulate plants to put out lush new growth that will entice aphids to set up home.
• Excessive pruning can also stimulate plants to put out attractive new growth.
• Use a row cover, especially on seedlings and new plants. This will keep out aphids but also protect from other pests.
• Control ants that can protect aphids.

For more information, check these websites:

https://ipm.ucanr.edu/PMG/PESTNOTES/pn7404.html#TABLE1

https://ipm.ucanr.edu/QT/aphidscard.html

 

Wingless adults and nymphs

Photo of wingless adult aphids and nymph-stage aphids

Aphids killed by parasitic wasps become mummies

Photo of paratisitic wasps and mummy aphids

Drought focus of Water Resources IMPACT magazine special issue

UC ANR experts address emotional toll of drought

Preparing the American West for prolonged drought is the focus of a double issue of Water Resources IMPACT magazine. The California Water Commission staff are guest editors for this special open-access edition of the magazine, which is published by the American Water Resources Association.   

Faith Kearns, academic coordinator of University of California Agriculture and Natural Resources' California Institute for Water Resources, is among the authors delving into how drought impacts people and the environment and how we can better prepare for the inevitable. 

The first issue, published on Feb. 14, focuses on water scarcity issues confronting California and the ways these issues affect different sectors. 

In “Trauma, Care, and Solidarity: Addressing the Emotional Toll of Chronic Drought,” Kearns highlights the effects of drought on mental health. She points to the spike in suicide hotline calls when wells ran dry in Southeast Asian communities in California's Central Valley.

By listening to Southeast Asian farmers, Ruth Dahlquist-Willard and Michael Yang of UC Cooperative Extension were able to “lighten the load” for them by providing pragmatic support, Kearns writes.

“The scale of some of these highly emotional issues – drought, wildfires, climate change – can make them seem incredibly difficult, if not impossible, to deal with,” Kearns said. “At the same time, they are affecting everyone living in the western U.S. on a daily basis. I wanted to highlight and provide models based on work that people – whether they are researchers, clinical psychologists, or Cooperative Extension advisors – are doing right now to ease the way.”

The authors who contributed to the double issue are a diverse array of Tribal experts, academics, nongovernmental organization thought-leaders, water managers and water policy influencers, each of whom brings their own perspective on the topic of drought. Their expertise and perspectives in climate science, water policy and water management will help inform drought-related decision-making and support policies that better prepare the state to thrive during periods of prolonged water scarcity.

In addition to Kearns, the first issue includes articles contributed by:

• Samantha Stevenson, University of California, Santa Barbara
• Jay Lund, University of California, Davis
• Ron Goode, North Fork Mono Tribe
• Andy Fecko, Placer County Water Agency
• Jeff Mount, Public Policy Institute of California, and Ted Grantham, University of California, Berkeley/UC Cooperative Extension
• Nat Seavy and Karyn Stockdale, National Audubon Society
• Kjia Rivers, Community Water Center
• Cannon Michael, Bowles Farming
• Michelle Reimers, Turlock Irrigation District

The January/February edition of Water Resources IMPACT magazine can be accessed, free of charge, on the American Water Resources Association website at https://www.awra.org under “Publications.”

The second issue, to be published in March, will focus on drought response, considering the options for adaptation. This two-part series complements the Commission's work on strategies to protect communities and fish and wildlife in the event of a long-term drought.

 

 

Read more