Facebook
X (Twitter)
Reddit
Pinterest
Tumblr
Delicious
LinkedIn
StumbleUpon
Posts Tagged: 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
Vole damage to turf showing burrows and runways. Credit: Terrell P. Salmon, UC IPM
Hardware cloth barrier. Credit: S. Hoyer
Because they cannot climb the metal sides, your plants can be safe from voles in beds like these. Credit: S. Hoyer
Another very effective option is to add an (at least 12-inch tall) metal flashing barrier to wooden raised beds. Credit: S. Hoyer
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.
What To Do About White Grubs in Your Vegetable Beds
It's Spring, and many gardeners are turning with anticipation to their vegetable gardening beds and thinking about summertime harvesting and feasting. If you're one of them, you may find an unexpected surprise of white grubs just below the surface when you start to prepare your soil for planting.
Although we typically think of grubs as being specific to lawns, where their root feeding can cause brown patches, they also show up in vegetable beds. Most of what we call grubs are the larvae of the Masked Chafer beetle. They are whitish with brown heads and legs, and when fully grown are about 3/4” long and c-shaped. This time of year they are just starting to migrate upward in the soil from about 8” deep where they have overwintered.
Unless there is a significant infestation, the best control for grubs is to handpick them from the bed as soon as you see them and leave them for the birds to find. If there are too many for hand-picking, another option is to apply beneficial nematodes (Heterorhabditis bacteriophora), which are tiny parasitic roundworms that enter the grub's body and kill it within a few days. Beneficial nematodes are often available at local nurseries.
Beneficial nematodes should be applied in the summer and early fall when the grubs are young, and are most effective when applied to soil that is over 60°F. The nematodes move through moist (not soggy) soil, so it's important to irrigate both before and after application. A second application about two weeks after the first will help with successful control. Keep in mind that beneficial nematodes are killed by light and heat, so it can be a good idea to apply them in the cooler, evening hours.
For more information on beneficial nematodes and how to apply them in your vegetable beds, please see our Pest Note at https://ipm.ucanr.edu/TOOLS/TURF/PESTS/innem.html
Help Desk of the UC Master Gardeners of Contra Costa County (RDH)
Citrus Care in the Sharing Season - Help Prevent the Spread of Asian Citrus Psyllid (ACP)
As gardeners, we're often generous with our garden's bounty. From sharing seeds and plant trimmings to the joy of gifting homegrown fruit and vegetables, gardening is as much about community as it is about growing plants. However, in this season of sharing, we must also remember our responsibility to prevent the spread of pests and invasive species to protect California's diverse ecosystem.
First detected in California in 2008, Asian citrus psyllid (ACP) has been a concern for both commercial citrus growers and home gardeners. ACP poses a significant threat to California's citrus trees, capable of spreading the deadly huanglongbing (HLB) disease, an incurable condition that eventually kills the tree.
Detecting ACP involves looking for a few key characteristics. ACP is a tiny, mottled brown insect about the size of an aphid. Adults are typically 3 to 4 millimeters long and are identified by their distinctive body shape, where the head is narrower than the body, and they hold their wings tent-like over their bodies. They are most active during warm temperatures, and you might notice them jumping or flying when disturbed. The nymphs, the immature form of the psyllid, are yellowish-orange and secrete white, waxy tubules from the back of their abdomen.
Additionally, ACP leaves telltale signs on citrus leaves, such as twisted or curled new leaf growth. They are sap-feeders, like aphids and mealybugs, so they produce honeydew which leads to the growth of sooty mold. Regularly inspecting your citrus trees, especially the new growth, is key to early detection of ACP.
Recent updates to the USDA's Plant Protection and Quarantine citrus map highlights areas that are generally infested with ACP and those which are not. This distinction is crucial for understanding the regulations and eradication efforts in different regions across the state. To find detailed quarantine information by county or zones, visit the California Department of Food and Agriculture (CDFA) ACP Regulation and Quarantine Boundaries website and maps.
Looking at the map pictured above, areas in the southern region of California, south of the Grapevine or San Gabriel and Tehachapi Mountain Ranges, and as far up the coast as Santa Barbara County are considered generally infested. The CDFA does not carry out eradication efforts for ACP in these areas. In areas north of the Grapevine, an ACP detection on a residential citrus tree would trigger an eradication response from the CDFA.
As we approach the holiday season, a popular time for gardeners to share budwood for grafting, it's crucial to understand the importance of not moving citrus planting material between quarantine areas. It is especially important not to move budwood or citrus from Southern California or the Bay Area into California's Central Valley.
To aid in this effort, UC Master Gardener Program resources are available to help educate you about identifying ACP and understanding the quarantine regulations. Here are some key actions you can take:
- Only purchase new citrus trees from reputable nurseries.
- Do not accept tree cuttings or budwood from friends or family.
- After pruning or removing a citrus tree, dry out the green waste or double bag it to help ensure the green waste is disposed of appropriately.
- Control ants in and near citrus trees with bait stations. Scientists have released natural enemies of ACP in Southern California to help keep the pest in check, but ants aid ACP in evading the natural enemies.
The UC Agriculture and Natural Resources ACP website offers an interactive map tool, biological control efforts, and an online calculator for the potential costs of using insecticides. Additionally, the Statewide UC Integrated Pest Management website provides free online training for gardeners and detailed Pest Notes on ACP and HLB disease. Remember, inspecting your citrus trees is vital to prevent the spread of ACP and HLB. If you suspect an infestation, contact the CDFA Exotic Pest Hotline at 1 (800) 491-1899 or your local county agricultural commissioner.
Let's continue to share the bounties of our gardens, but let's do so responsibly, keeping our citrus trees safe and healthy. Together, we can make a difference in the fight against ACP and HLB.
Weeds and Wildfires
How can weed control help with wildfire preparedness? Wildfires are part of California's ecosystems, and they do not have to lead to the destruction of structures and livelihoods. Each of us can contribute to improving wildfire resilience, from...
