Posts Tagged: Karrie Reid

Your water-efficient landscape doesn’t have to be barren

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

While attending UC Davis as a master's student, Karrie Reid, retired UCCE environmental horticulture advisor for San Joaquin County, assisted Oki with landscape water conservation research. The landscape plant irrigation assessments were initiated at UC Davis in 2004 and the UCLPIT project, now in its 20^th year, originated from her master's thesis project from 2005 to 2007. A CDFA grant supported duplicating these fields at the South Coast REC in 2017.

“(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/

San Joaquin County UCCE one of two sites in California for sustainable rose trials

San Joaquin County UC Cooperative Extension in Stockton maintains pesticide-free roses as one of two trial sites in California for the American Rose Trials for Sustainability, reported Angelina Dequina in the Daily Titan. The other California location is at California State University, Fullerton.

Since 2012, the American Rose Trials for Sustainability has conducted scientific research to determine the best rose cultivation techniques for gardeners in each region of the U.S. The roses in the trial plots are grown with minimal care; the only inputs are water and compost. The San Joaquin County roses are maintained by UC Master Gardeners in the UCCE Learning Landscape, which beautifies the Robert J. Cabral Agricultural Center and features a series of small, themed, climate-appropriate gardens. 

The Learning Landscape is used for educational Open Garden Days and to teach a variety of workshops for landscape professionals. The public is welcome to stroll the gardens seven days a week during daylight hours. The facility is at 2101 E. Earhart Ave. in Stockton.

Project lead Karrie Reid, UCCE San Joaquin County environmental horticulture advisor, said the rose trials are integral to the marketing of rose cultivars, according to the Daily Titan article.

Once the two-year trial ends, the trial gardens may keep the roses they planted.

San Joaquin County gardeners boost business with UC Cooperative Extension Green Gardener qualification

For a healthier family and environment, San Joaquin County homeowners can select a UC-qualified Green Gardener to take care of their lawns and landscapes.

Green Gardeners are landscape professionals who are trained and tested on up-to-date, environmentally friendly, science-based landscape practices.

“We're improving the knowledge and skill sets of workers who manage an enormous amount of urban acreage,” said Karrie Reid, the UC Cooperative Extension horticulture advisor in San Joaquin County. “We're helping them understand that they have the power to effect change in water conservation, quality of storm water runoff, and the amount of pesticides that are in the environment.”

To become qualified as a Green Gardener, participants attend classes eight weeknight evenings and two Saturday mornings. The first module addresses the importance of healthy soil for healthy landscapes. UC Cooperative Extension scientists provide training on soil building, pest control and green waste management. The second module focuses on mastering efficient irrigation and conducting an irrigation audit. The final sessions focus on plants in the California landscape, including turfgrass, trees and shrubs.

Because the Green Gardener program is partially funded by a dumping fee paid by residents to the county landfill, green waste management is a key component of the program.

“We have to reduce our green waste,” Reid said. “Our urban soils are in need of organic matter. By building soil with green waste, we are solving two problems that inhibit our urban landscapes' sustainability.”

Beginning with Module 1, the Green Gardener qualification program is being held for the fifth time Jan. 16 to March 12, 2018. The registration deadline is Jan. 12.

On the first day of an earlier session, a landscaper wondered aloud if the $90 fee and, particularly, the time commitment, would be worth it. “Well, I know the answer is that it was worth it,” he said.

In addition to all the knowledge gained, after passing the class, the participants can place the Green Gardener logo on their advertisements and be added to the online list of qualified UCCE Green Gardeners.

One Green Gardener, Jacob Wilson, wrote to Reid about a visit to a customer's property after a four-week break and found the lawn was significantly greener.

“I asked the customer if she had her sprinklers repaired,” Wilson said. “She said, ‘No, my sister adjusted the water schedule to two or three times during the night with shorter watering duration each time instead of watering once; like you said.'”

As his customer made her way back to the house, Wilson said he was feeling more like a professional.

Home gardeners aren't the only ones who can take advantage of the program. Reid has reached out to landscape professionals working in the county parks department and school districts. There are landscapers who tend apartment complex landscapes, commercial building landscapes, street medians and highway rights-of-way.

“I successfully pitched the program to the Sherriff's Department for their grounds landscape personnel,” Reid said.

For more information, visit the Green Gardener of San Joaquin County website at http://ucanr.edu/sites/GreenGardener.

6 ways to reduce water use without killing your garden

To conserve water and meet California's new water-use restrictions, one place to start is literally in one's own backyard. More than half of all household water use is typically used outdoors on landscape, according to University of California Agriculture and Natural Resources experts.  

For homeowners, there are six key things to do to conserve landscape water, says Karrie Reid, UC ANR Cooperative Extension advisor, in San Joaquin County. Reid gives the following six tips:

1. Tune up your irrigation system right away. When water is efficiently and accurately applied, less water is needed to keep plants healthy. Spray heads can get knocked out of alignment and end up spraying the sidewalk, street or driveway and running to the gutter. Check all spray heads to ensure they are hitting the target and twist those that aren't back into place. Some heads have adjustable angles of spray, which can be fixed with a tool available at a hardware store. Look for cocked heads, which spray water up into the air, and sprays blocked by grass or those that have sunk below grade. Make sure all spray heads are made by the same manufacturer and are from the same line so they deliver water at the same rate, otherwise they'll leave dry spots. Low-volume spray heads or rotators deliver water more efficiently.
   
   
2. 

   To check the watering depth, use a soil probe.
   Water the whole root zone. On allowed watering days, irrigate until the water reaches 12 inches deep for grass, 12 to 18 inches for shrub and perennials, and 12 to 24 inches for trees. This provides a greater reservoir of water for the plants to draw from, and many will be able to get by on weekly, twice-monthly or monthly irrigation if they are conditioned to send their roots deep. To check the watering depth, use a soil probe or push a long screwdriver into the ground. The depth it reaches easily indicates how deeply the water has infiltrated.
3. Avoid wasting water to runoff. If water runs off before the watering cycle finishes, split the cycle time. Set the timer to water in two, three or even four cycles at least an hour apart to allow the water to soak in. To ensure water isn't flowing below the root zone, check the watering depth after each cycle.

   An irrigation scheduling worksheet created by Loren Oki, UC ANR Cooperative Extension specialist in the Department of Plant Sciences at UC Davis, and Darren Haver, UC ANR Cooperative Extension advisor in Orange County, helps fine tune irrigation timing. The worksheet is available for free online at the Center for Urban Horticulture website http://www.ccuh.ucdavis.edu.  

4. Switch to inline drip tubing for beds.  Drip irrigation applies water where it is needed with less loss to the air. Be sure to lay tubing so water reaches plants' entire root zone.
   
   
5. MULCH, MULCH, MULCH. Adding 3 or 4 inches of organic material such as wood chips, shredded bark or bark nuggets will improve soil health while retaining water and lowering stress on your plants. Place mulch away from the street curb to prevent heavy rains from washing it into the storm drains.
   
   
6. 

   Inline drip tubing applies water where it is needed.
   Replace water-needy plants with low water users in the fall. All plants use a lot of water to get established when they are planted in the spring and summer, and for about a year after. Trees may need extra water for several years until their roots have grown well into the surrounding soil. By waiting until temperatures cool in the fall to plant, it will be easier to abide by the water restrictions. It's also important to use hydrozoning, which means placing plants with the same water needs on the same valve.  Otherwise, irrigating to the thirstiest plants on that station will give other plants more water than they need.

To find low-water use plants that are suitable for a specific location, check UCANR's online Water Use Classification of Landscape Species at http://ucanr.edu/sites/WUCOLS. Click the Plant Search Database tab, enter the name of the city, then select the desired type of plants (shrubs, perennials, trees, etc.) and the preferred water category (low, moderate, high).  The application will generate a list of plants suitable to grow in a location that fit the specified criteria.

Grasscycling can help Californians conserve water

Gov. Jerry Brown asked Californians to cut water use by 20 percent a year ago. Officials at the State Water Resources Board announced in March that water users haven't come close to meeting the conservation goal. To help homeowners save water while maintaining a beautiful lawn, UC Agriculture and Natural Resources (UC ANR) horticulture advisors recommend “grasscycling” turf at homes, schools, parks and businesses this spring and summer.

In short, grasscycling involves leaving grass clippings on the lawn, rather than collecting them in a bag and shipping them off to a landfill.

“The clippings sift down to the soil surface and act like a mulch, reducing water evaporation so you can cut back on irrigation,” said Karrie Reid, UC ANR Cooperative Extension environmental horticulture advisor in San Joaquin County. “This is a simple and elegant way to save water that requires very little extra effort.”

If you don't have a mulching mower, Reid says, “It's probably time to replace the mower.” As an alternative, a mulching blade can be attached the bottom of most mowers. The special blade makes a second cut when mowing over grass, cutting grass clippings into finer pieces.

In most California climates, mowing once a week with a mulching mower is sufficient. If grass is growing so quickly a once-per-week mowing cuts off more than one-third of the blade, it's a sign that too much water is being applied.

In addition to reducing water use, grasscycling cuts down on fertilizer needs.

“As the clippings break down, nutrients are returned to the soil,” Reid said. “Most of the fertilizer that is applied to lawns ends up in the leaf blades, so it only makes sense to retain as much of that on the lawn as possible.”

A five-page UC ANR publication on mowing and grasscycling is available for free download from the UC ANR Catalog. The publication includes a table with mower height settings for the most common types of turf grass grown in California.

In addition to working with horticulture professionals, Reid serves as advisor to the coordinator and volunteers of the UC Master Gardener program in San Joaquin County. Master Gardeners are UC ANR volunteers who are trained by UC academics in sustainable landscape, ornamental tree and garden development and maintenance.

More than 6,000 volunteer Master Gardeners form a network to disseminate research-based gardening information across the state, donating upwards of 350,000 hours of time each year.

An initiative to improve California water quality, quantity and security is part of the UC Division of Agriculture and Natural Resources Strategic Vision 2025.

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