- Author: Barbra Braaten
Water is essential for any garden, but it's crucial to use water wisely in a place like California, where droughts are common. Effective water management can help home gardeners keep their plants healthy while conserving this precious resource. Thoughtful water management uses resources efficiently and sustainably to meet current and future needs. It involves planning, developing, distributing, and managing the optimum use of water to ensure plants survive and look good. By conserving water, home gardeners contribute to the preservation of local ecosystems and the sustainability of the environment.
Plant Water Use
Understanding how much water your plants need is the first step in effective water management. Different plants have different water requirements. For instance, succulents and cacti need less water than vegetables or fruit trees. It's important to group plants with similar water needs together. This way, you can avoid overwatering or underwatering specific plants. You can learn about plant water needs from plant labels, gardening books, or by reaching out to your local UC Master Gardener volunteers for support. Additionally, observing your plants and learning their symptoms of water stress, such as wilting or drooping leaves, can also help inform water management.
Watering Systems
Several watering systems can help manage water use in a garden. Drip irrigation is one of the most efficient methods. It delivers water directly to the roots of plants, minimizing evaporation and runoff. Soaker hoses, porous hoses that seep water along their length, are another good option for watering garden beds. Traditional sprinklers can be used, but they are less efficient because they tend to waste water through evaporation and runoff. Newer, more advanced systems include weather-based controllers that adjust watering schedules based on weather conditions, ensuring plants get the right amount of water without waste.
Irrigation Best Practices
Take a proactive role in water conservation by adopting best practices for irrigation. Watering early in the morning or late in the evening reduces evaporation, ensuring more water reaches the plants. Mulching the garden helps retain soil moisture and reduces the need for frequent watering. Regularly checking for leaks in the irrigation system and repairing them promptly can prevent water loss. Adjusting the watering schedule based on the season and weather conditions is also essential. During cooler months or after rainfall, plants need less water; in the hot summer, they may need more frequent watering.
Use Drought Tolerant Plants
One of the most environmentally responsible ways to conserve water in a garden is to use drought-tolerant and/or native plants. Drought tolerance reflects the ability of a plant to withstand less than optimal water supplies due to adaptive or avoidance mechanisms. While many native plants possess drought-tolerant traits and require less supplemental irrigation once established, many non-native plants Mediterranean-adapted plants also thrive on relatively lower water. It is important to remember that these plants require water regularly until their root structure is well established in landscape soil. Maintaining these plants with deep and infrequent irrigation once established is a great way to reduce landscape water use. By incorporating these plants into your garden, you're also providing habitat for local wildlife. This creates a beautiful, low-maintenance landscape that thrives with less irrigation.
Best Practices for Keeping Plants Alive During a Drought
During a drought or under water restrictions, it's essential to prioritize how you use water in the garden. Focus on watering the most valuable and vulnerable plants first, such as shade trees and young trees. Slow, deep watering is more effective than frequent shallow watering. This involves watering to a depth slightly below the plant root zone which encourages roots to grow deeper into the soil, making plants more drought-tolerant. Reducing the size of your lawn or replacing it with drought-tolerant ground covers can also save significant amounts of water. Additionally, using shade cloth or temporary shading can help reduce water loss by protecting plants from intense sunlight.
By understanding plant water use, choosing suitable watering systems, adopting best irrigation practices, using drought-tolerant plants, and implementing drought survival strategies, California home gardeners can maintain a healthy and beautiful garden while conserving water. Water management is beneficial for your garden and the environment, and is an especially important practice for Californians. Your conscious efforts in water management contribute to the sustainability of our environment.
To learn more please reach out to your local UC Master Gardeners Program.
- Author: Lauren Fordyce
In February we recognize Valentine's Day, President's Day, and Black History Month, but did you know it is also IPM month?! Join us in celebrating by learning more about integrated pest management (IPM), how you can use it in your everyday life, and the pest management resources and information offered by UC IPM.
What is IPM?
Integrated pest management (IPM) is a more sustainable, environmentally friendly method for managing pests like insects, diseases, weeds, and unwanted wildlife. IPM can be used by anyone: homeowners, tenants, farmers, gardeners, janitors, groundskeepers, professional landscapers and pest control operators, and more.
IPM focuses on the long-term management of pests through prevention and monitoring. This reduces pests reaching damaging levels and becoming difficult to control or requiring pesticide use. One way pests can be prevented outdoors is by providing plants with proper care (water, sunlight, and nutrients). You can prevent pests from coming indoors by sealing gaps around windows and doors. Monitor for pests using tools like sticky traps, or visual inspection.
Once a pest becomes a problem, it must be correctly identified so the correct management solution can be chosen. Many pests can be managed without the use of pesticides. In IPM, we often choose nonchemical solutions first:
- Biological control: the use of natural enemies—predators, parasites, pathogens, and competitors—to controlpests and their damage. Some examples of natural enemies include ladybeetles, lacewings, and spiders.
Protective covers or netting can keep pests off plants. In IPM this is an example of physical or mechanical control. Photo by Krystle Hickman, UC IPM. - Cultural control: practices that limit pests from establishing, reproducing, and living where they're not wanted. These practices can include increased cleanliness, proper storage of food, good plant care, and well-maintained landscape irrigation systems.
- Mechanical or physical control: kill a pest directly, block pests out, or make the environment unsuitable for them. Examples include traps for rodents, mulches for weed management, and flyswatters for flying insects.
Pesticides can still be an important part of IPM, but they should be used in combination with nonchemical solutions for long-term management. Pesticides alone will not solve a pest problem or prevent pests from becoming a problem again later. When pesticides are needed, choose products that are less toxic. Less toxic pesticides are those that pose fewer risks to people, pets, the environment, and natural enemies like ladybeetles. Learn more about less toxic pesticides at https://ipm.ucanr.edu/QT/lesstoxicinsecticidescard.html.
Whether you are trying to control cockroaches in an apartment, weeds in the garden, or diseases on landscape plants, UC IPM has the tools and resources to help you using an IPM approach.
To learn more about integrated pest management, visit https://ipm.ucanr.edu/what-is-ipm/ or view our resources for managing specific home, garden, and landscape pests using IPM at https://ipm.ucanr.edu/PMG/menu.homegarden.html.
- Author: Trina Kleist, UC Davis
One more reason to adopt sustainable cultivation
California wheat farmers could both maintain their yields and improve soil health by growing annual wheat without tilling the soil year after year.
This could be one more encouragement to farmers to adopt a sustainable practice commonly called conservation tillage, no-till or minimum-till cultivation, impacting how we grow a grain that supplies about 20 percent of the calories and protein for people around the world.
A new study, by a team led by Mark Lundy, University of California Cooperative Extension specialist in UC Davis' Department of Plant Sciences, offers new insight for decades-long discussions around soil conservation, sustainable agriculture and climate-warming emissions related to growing our food. The study has been published in the journal Soil and Tillage Research. For the first time, researchers have shown that annual wheat that is not tilled each year is better for stashing carbon in the soil than perennial wheatgrass, while still yielding more crop in Central California.
Previous studies have looked at annual wheat that is tilled each year, annual wheat that is not tilled, and a cousin species, perennial intermediate wheatgrass (trademarked Kernza), which also is not tilled. But until now, no one has looked at all of the benefits and trade-offs together. Most importantly, “no one has ever controlled for tillage,” Lundy said. “And, no one has compared annual wheat to perennial intermediate wheatgrass over multiple years in a Mediterranean climate, which is what we have in California.”
This study also is unique because it delves into the deeper question of what is going on in the soil that drives the different results for carbon there. Soil carbon reflects various processes linked to plant activity and soil health. Measuring the different forms of soil carbon may also signal whether a farming system is accumulating carbon in the soil over time – a plus for reducing climate-warming gases in the atmosphere.
“Measuring soil carbon is complex and nuanced,” said Kalyn Taylor, the lead author on the paper. “We started this experiment because we wanted to know whether and how plant activity and tilling or not tilling would affect the carbon story belowground in California's climate.”
“When we started this study, we thought the crop being perennial or annual would drive the differences in carbon storage in the soil,” Lundy added. Specifically, they had expected perennial wheatgrass would lead to more carbon in the soil because of its deeper, better-established root system. “But that's not what we found,” he went on. “What we found was, it was the lack of tillage, plus the level of productivity of common annual wheat, that made the difference in soil carbon here in California.”
Soil carbon in annual vs. perennial grain
In 2017, Lundy, then-graduate-student Taylor, UC Davis Professor Emeritus Kate Scow and others on the team started measuring different forms of soil carbon in test plots at Russell Ranch, west of campus. Plots were planted with annual wheat that was tilled each spring, annual wheat that was not tilled and perennial intermediate wheatgrass (Kernza) that also was not tilled.
Each year, the researchers measured the carbon present in the soil, the amount of soil organisms (which have carbon in their bodies) and the amount of material the plants created.
At the end of three growing seasons, they found that land planted with no-till, common, annual wheat had the highest amount of soil organisms, measured as biomass, of the three treatments.
The researchers also found soil carbon is more likely to remain stable in the no-till, annual plots, compared to both tilled wheat and wheatgrass.
In addition, the no-till, annual wheat produced plant material more consistently than the perennial wheatgrass across the three years, which saw variation in rainfall.
“Overall, annual wheat grown without soil disturbance or tillage had both higher productivity and higher potential for storing carbon in the topsoil than perennial wheatgrass in our Mediterranean climate,” Lundy said.
Related research
“No-till annual wheat increases plant productivity, soil microbial biomass, and soil carbon stabilization relative to intermediate wheatgrass in a Mediterranean climate,” is online now and will be published in the January 2024 edition of Soil and Tillage Research.
The team also found that tilled annual wheat vs. Kernza stores total carbon at different depths in the soil profile and hosts distinct soil fungal communities, primarily in the root zone and topsoil: Taylor, K., Samaddar, S., Schmidt, R., Lundy, M. and Scow, K., 2023. Soil carbon storage and compositional responses of soil microbial communities under perennial grain IWG vs. annual wheat. Soil Biology and Biochemistry, p.109111.
Previous work comparing the perennial grain known as intermediate wheatgrass (trademarked Kernza) to annual wheat had not distinguished the extent to which soil health benefits are a function of the perennial nature of the crop. Read the story here.
This story was originally published on the UC Davis News site.
- Author: Anne Schellman
Mark your calendar for Tuesday, November 28, 2023! Giving Tuesday is an opportunity for you to make a donation to a program that has made a difference in your life.
We invite you to support us in our quest to promote healthier gardens, people, and more sustainable landscapes.
Here are some photos of our UC Cooperative Extension Master Gardeners in action helping make Stanislaus County a better place.
- Author: Saoimanu Sope
UC climate-ready landscape trials identify low-water yet attractive plants
Good news: roses can be a part of your water-efficient landscape. Lorence Oki, UC Cooperative Extension environmental horticulture specialist in the UC Davis Department of Plant Sciences, identified rose cultivars that remain aesthetically pleasing with little water.
Oki is the principal investigator of the Climate-Ready Landscape Plants project, which may be the largest irrigation trial in the western U.S., and the UC Plant Landscape Irrigation Trials (UCLPIT), the California component of that project. These projects evaluate landscape plants under varying irrigation levels to determine their optimal performance in regions requiring supplemental summer water.
“There are some assumptions that pretty plants use a lot of water, like roses,” Oki said. “Everyone thinks they need a lot of water, but we've found some that don't, and they still look great. A water-efficient landscape doesn't need to look like a Central Valley oak-grassland in the summer. It can look really attractive.”
In 2021, Oki's team at UC Davis identified Lomandra confertifolia ssp. pallida "Pom Pom" Shorty and Rosa "Sprogreatpink" Brick House® Pink as two of the best low-water plants in the trial. 
“The useful tip or information that is shared at the end of each trial is the selection and designation of plants as Blue Ribbon winners. These are the plants that looked good with an overall rating of 4 or higher throughout and were on the low (20%) water treatment,” said Natalie Levy, associate specialist for water resources, who manages the project at the UC ANR South Coast Research and Extension Center.
How plants earn a blue ribbon
Each trial year, the selection of new plants is based on research recommendations and donated submissions from the nursery industry. The landscape plants are trialed in full sun or 50% shade cover.
Irrigation treatments are based on the rate of evaporation and plant transpiration (evapotranspiration) measured through a local California Irrigation Management Information System (CIMIS) weather station that provides a reference evapotranspiration (ETo) rate.
Three levels of irrigation are provided to the plants equal to 20%, 50%, and 80% of ETo. The volume of water applied is the same at each irrigation based on soil characteristics, but the interval between applications varies with weather and the treatment. Using this method, irrigations for the 20% treatment are less frequent than the 80% treatment.
“The 20% treatment during the 2022 trial was irrigated an average of once per month while the 80% treatment was irrigated weekly,” explained Levy.
During the deficit irrigation trial, monthly height and width measurements are taken to determine the plant growth index. Monthly qualitative aesthetic ratings on a scale of 1 to 5 are determined for foliage appearance, flowering abundance, pest tolerance, disease resistance, vigor and overall appearance.
A second round of flowering abundance and overall appearance measurements are also taken to capture more of the blooming period. For example, UCLPIT identified in the 2020 trial at South Coast REC that the "Apricot Drift" rose had a mean overall appearance score of 3.5 out of 5, deeming it “acceptable to very nice” and a low water use plant within the Water Use Classification of Landscape Species or WUCOLS guide.
Project expands options for landscape planting
“(WUCOLS) only has 3,500 plants in it. There are guesses that there are close to 10,000 cultivars in urban landscapes in California, if not more,” said Oki. “WUCOLS also didn't have numerical ratings. Instead, you'll see verbal ratings like ‘low water use' or ‘high water use.'”
The UCLPIT project has not only developed numerical recommendations for irrigation, but it has also added new landscape plants that are compliant with California's Model Water Efficient Landscape Ordinance. In fact, UCLPIT's data is one of the few sources that can be used to supplement WUCOLS.
Geographic diversity of trial sites adds to knowledge base
In addition to UC Davis and South Coast REC in Irvine, the trials have expanded beyond California as the Climate-Ready Landscape Plants project and is in progress at Oregon State University, University of Washington, University of Arizona and Utah State University thanks to a USDA/CDFA grant awarded in 2020.
Lloyd Nackley, associate professor of nursery production and greenhouse management at Oregon State University, is the principal investigator of the trial in the Portland metro area, which is entering its third year.
“People know that there are drought tolerant plants, but there are many. We're trying to highlight lesser known or newer varieties. And even though the trial is three years, most gardeners would hope that their garden lasts longer than that,” said Nackley.
One of the observations that Nackley recalls is of the Hibiscus Purple Pillar plant. Unlike the trial at South Coast, the Purple Pillar did not perform well in Oregon in the spring.
“It wasn't until August that we saw the plant bloom and begin to look like what we saw from South Coast in April,” Nackley said.
Ursula Schuch, horticulture professor and principal investigator of the trial taking place at the University of Arizona, was also surprised at the range of performance among different plant types and the effects of irrigation, heat and temperature.
“This research will reassure green industry professionals that they can stretch their water budget to successfully cultivate more plants, watering them according to their needs instead of irrigating every plant according to the highest water-using plants,” said Schuch.
Although research is only conducted in the West, the hope is that there will be trials in other regions of U.S.
Doing so would yield comprehensive information about the plants and their performance in different climates. As extreme weather events persist in the U.S., disease pressure and risks do too. Trials throughout the country would provide location-specific data regarding disease susceptibility.
To learn more about the UCLPIT research project, visit https://ucanr.edu/sites/UCLPIT/
