- Author: Saoimanu Sope
‘Ag Order' for San Diego County expected to be enforced by end of 2023
Generally known for its steady warmth and picturesque beaches, San Diego County is also home to nearly 5,000 small farms and is an economic hotspot for nurseries and floriculture. But the great diversity of ornamental crops that dominate the growing region and complexity of regulations make compliance challenging for growers, some of whom grow over 400 crop varieties.
“The regulatory environment for the growers is still complicated and overwhelming because, along with the Regional Water Board, growers are regulated by the County of San Diego,” said Gerardo “Gerry” Spinelli, University of California Cooperative Extension production horticulture advisor for San Diego County.
To help growers with compliance, Spinelli is prioritizing education and expanding growers' knowledge. By partnering with organizations such as the Farm Bureau of San Diego County and the San Diego Region Irrigated Lands Group, Spinelli works to reach more than 1,200 growers, supporting them as they navigate regulatory agencies.
Formally referred to as the Regional Water Quality Control Boards, the Regional Water Board aims to develop and enforce water quality objectives and implement plans to protect the beneficial uses of California's waters.
A unique place to grow in California
About 10 years ago, the Regional Water Board created the Agricultural Order (Ag Order), a set of rules outlining how growers manage water discharge from agricultural operations.
The new Ag Order for San Diego County, expected to be enforced by the end of 2023, will focus on nitrogen management and groundwater quality. However, new considerations are needed to address the variety of crops grown by a single farmer, a common practice in San Diego.
Calculating nitrogen input and output for more than 400 crop varieties is not feasible for small farmers, a challenge exacerbated by the meticulous attention needed for San Diego's high-end specialty crops like ornamentals, native plants and specialty fruit.
Furthermore, many San Diego growers have limited expertise and experience because they are entering agriculture as a second or third career. Many have become “accidental growers” in that they purchased land with a preexisting avocado or cherimoya grove, for example.
To help address these challenges, the grower community is emphasizing the need for more educational opportunities that are accessible and relatable.
Equipping growers through education
Enrico Ferro, president of the San Diego Region Irrigated Lands Group – a third-party entity that manages water sample testing on behalf of growers – has relied on Spinelli's teaching to “bridge the gap” for growers, including himself.
“Gerry has been great because he has expertise in nurseries, but the educational content he creates is relevant to all growers,” said Ferro, who is an avocado and citrus grower in San Diego's North County.
Spinelli, who specializes in containerized production in nurseries and floriculture, has been instrumental in providing technical assistance to growers since he joined Cooperative Extension in 2020.
“I started teaching over Zoom since I became an advisor during the pandemic, and I try to cover different topics for each training,” Spinelli said, adding that he teaches in English and Spanish, making his content more accessible to the grower community in San Diego.
For in-person educational opportunities, Spinelli created the “Last Wednesday” monthly meetings hosted at the Farm Bureau of San Diego County, which brings together growers and other agricultural experts to learn from one another.
“We try to get our information out in creative ways and Gerry is instrumental in that. He's our primary source of really wonderful information delivered in an engaging way,” said Tasha Ardalan, program coordinator for the SDRILG. “He's proactive and is always willing to try new things, too.”
Planning for San Diego's agricultural future
Currently, the Ag Order is modeled around regulations for the Central Valley. As conversations and planning for San Diego County continue, Spinelli is supporting the Regional Water Board with information on nurseries and greenhouses in hopes that the final Ag Order will better serve San Diego growers.
“I'm trying to help others understand how nursery and greenhouse production systems function, and how and why they are different from an almond orchard or tomato field in Fresno,” explained Spinelli.
Michael Mellano, CEO of Mellano & Company, a fresh cut flower grower and distributor in Oceanside, feels the impact of the Ag Order and its failure to account for variability. Growing over 100 varieties of flowers, Mellano said that for several plants there is little scientific research on how much nitrate to apply.
“Farmers want to do a good job. We make mistakes and we try to fix them as quickly as we can, and we try to educate others on what works,” said Mellano, who is also a member of the SDRILG.
Growers like Mellano and Ferro agree that the farming community in San Diego needs to be given the latitude to solve problems within their means, an ability that requires an understanding of San Diego's uniqueness.
“San Diego is significantly different, and we need an Ag Order that is reflective of our differences,” said Valerie Mellano, SDRILG consultant and former UCCE environmental issues farm advisor. “In developing the new Ag Order, there's a huge opportunity for education and research, something that we know Gerry can easily do and continue to support us in.”
Thus far, Spinelli's educational content has reached two-thirds of SDRILG's 1,200 members. In addition to the live training sessions, growers can watch videos that cover topics such as evapotranspiration, irrigation distribution uniformity, water quality indicators and more on Spinelli's YouTube channel.
Since the Ag Order requires all growers to complete two hours of water-quality education, the SDRILG has agreed to apply one hour of credit to growers who attend a one-on-one session with Spinelli.
As San Diego's growers continue to leverage educational opportunities – whether it's alongside Spinelli, SDRILG or learning from one another – Spinelli emphasized that their success also relies on an ag order that adheres to a distinctive landscape, multitude of specialty crops and growers with varying expertise.
- Author: Christine Casey
- Author: Lea Corkidi
Regular Haven visitors notice that we frequently change our planting. It's one of the joys of gardening -- there are always new plants to try and experiment with. At the Haven, research on new plants and methods for bee gardens is essential to our educational mission.
Previous posts have reported on our work with bee plant preferences, with an emphasis on low-water plants. Our colleagues at UC Cooperative Extension in Southern California have done similar work for that part of the state. Previous blog posts have covered research with mulch, plant color, and water; all are important components of a healthy bee garden.
But all this is for naught if it isn't put into practice. So our current work is to create tools for the California horticulture industry to educate employees and customers about bee garden best practices based on this research. The first step in this work is development of an efficient sampling method so growers, landscapers, and public gardens can easily assess the bee-attractiveness of new plants as they come on the market. This will allow these plants to be marketed correctly, and will also help growers to target bee-friendly pest management.
In our attractiveness studies the Southern CA team used timed counts, while the Northern CA team used a snapshot count method (1). This technique consists of 20 second quick counts of every plant that is repeated three times in succession rather than a single 3-minute timed count. The snapshot count is faster to complete and more readily worked into the day of an otherwise busy nursery employee.
The purpose of this study was to calculate the relative net precision (RNP) of each bee counting method at a wholesale nursery (Fallbrook, CA) and a public garden site (Encinitas, CA) in San Diego County. RNP is calculated as shown below and is a way to assess sampling efficiency by balancing precision and sampling cost (2).
RNP = [1/(cost x Rv)] x 100, where Rv = (SE/mean) x 100
Plants in full bloom were sampled weekly for at least 4 weeks using both methods. Bees were counted as honey bees or other bees as this distinction is easy for an untrained observer; only honey bee data is reported here. At both locations, we saw a larger absolute number of bees with the snapshot method, but the trend of most attractive to least attractive was the same for both methods (Figures 1 and 2). We are most interested in this trend rather than the absolute number, which is expected to vary between locations. Additionally, regression analysis shows that the two counting methods are strongly correlated (Figure 3).
Finally, we saw differences between the RNP values calculated for the two sampling methods, with higher RNP for the snapshot method at both locations (Table 1). Higher RNP means greater sampling efficiency (2).
A second year of study will begin in April at additional sites to confirm these findings. We look forward to providing the California green industry with a useful tool for supporting pollinator gardens.
References
1. Garbuzov and Ratnieks. 2014. Functional Ecology 28: 364-374.
2. Buntin pp 99-115 in Handbook of Sampling Methods for Arthropods in Agriculture. CRC Press, Boca Raton, FL. 1994.
- Author: Ed Perry
Citrus trees grow best in loam or sandy loam soil, but you can grow them in most soils that have good drainage. If your soil drains poorly, you might try planting in a raised bed or on a mound. Plant your trees in an area that receives full sun, and allow enough room for the tree's mature size. I don't recommend planting in a lawn area because it's difficult to irrigate both the citrus and the lawn correctly. Also, the grass tends to absorb many of the nutrients needed by the tree.
Dig the planting hole just deep enough to plant the tree at the same level that it was in the nursery. The diameter of the hole should be about 6 inches larger than the root ball. If the hole is too deep, the tree will settle too much after planting. Trees that settle too deep are likely to be killed by crown rot, a fungus disease that frequently develops where the soil covers the bark of the tree.
You can place balled and burlap-wrapped trees in the planting holes without removing the cloth sacking that covers the roots. Plant them a little higher than they were in the nursery, allowing about 3 inches for settling. Try to have the uppermost roots branch out at about ground level after the trees have settled.
Do not put any fertilizer in the hole when planting your tree because it may damage the roots. It's safer to apply fertilizer to the surface of the soil after you've planted. If you use manure, use it lightly because roots may be damaged by salts which manures contain.
Citrus trees do very poorly in dry soil, so be sure to pay close attention to irrigation, especially during the first summer.
Ed Perry is the emeritus Environmental Horticultural Advisor for University of California Cooperative Extension (UCCE) in Stanislaus County where he worked for over 30 years.
- Author: Ben Faber
California Horticulture Sales Reach $2.63 Billion in 2019
U.S. Horticulture Operations Report $13.8 Billion in Sales
Sacramento, CA, Dec. 9, 2020 – On Tuesday, December 8, the U.S. Department of Agriculture's National Agricultural Statistics Service (NASS) released the 2019 Census of Horticultural Specialties report, the only source of detailed production and sales data for floriculture, nursery, and specialty crops for the entire United States. The data show that horticulture operations in California sold a total of $2.63 billion in floriculture, nursery and specialty crops in 2019, down 9% from the sales in 2014. California sold 19% of the total U.S. horticulture sales of $13.8 billion in 2019, more than any other state. In addition to sales, the number of horticulture operations in California decreased 22% during this time to 1,331, and the number of operations in the United States decreased 11% during this time to 20,655.
“The horticulture census is a vital tool that highlights the contribution horticulture growers bring to our local, state, and national economies,” said Pacific Region Director Gary R. Keough. “It shows changes and trends in the industry over the past five years and beyond.”
Horticulture production occurred primarily in 10 states, which accounted for 66% of all U.S. horticulture sales in 2019. California ($2.63 billion), Florida ($1.93 billion) and Oregon ($1.02 billion) led the nation in sales.
The top five commodities in California horticulture sales in 2019, and compared to 2014, were:
- Nursery stock, $831 million, down 13%
- Potted flowering plants, $322 million, up 7%
- Transplants for Commercial Vegetable and Strawberry, $266 million, up 4%
- Cut flowers & cut lei flowers, $249 million, down 26%
- Annual bedding/garden plants, $232 million, up 6%
Other key findings for California from the 2019 Census of Horticultural Specialties report include:
- Family- or individually-owned operations made up the largest number of operations, accounting for 48%, but corporately-owned operations accounted for 80% of sales ($2.11 billion).
- Total industry expenses were at $2.21 billion in 2019, with hired labor being the largest cost, accounting for 36% of total expenses.
The Census of Horticultural Specialties is part of the larger Census of Agriculture program. It provides information on the number and types of establishments engaged in horticultural production, value of sales, varieties of products, production expenses and more. All operations that reported producing and selling $10,000 or more of horticultural crops on the 2017 Census of Agriculture were included in this special study.
For more information and to access the full report, visit www.nass.usda.gov/AgCensus.
- Author: Karrie Reid
Did you ever wonder how that latest plant variety made its way to your local nursery? Few people outside of the plant breeding and marketing industry realize that the “new” plant you just saw at the garden center last weekend actually began its journey from 6 to 20 years earlier 1 . One of the last steps in that journey is the plant trial.
Plant trials take place all over the country at universities and public gardens and are usually the last step before a company decides to launch a new cultivar onto the market. Although they will have evaluated a promising new cultivar in a company field, the information received from a third-party trial has the advantage of being unbiased. Those plants that prove themselves novel, attractive, and hardy are then branded and put into the latest catalog.
Focus on sustainability
The vast majority of university and botanical garden or arboretum trials are designed to provide ideal growing conditions— ample water and fertilizer — to maximize the potential of the plants. At the University of California, Davis, we go about plant trials in a completely different way. Our goal is to reveal the best perennial plants for sustainable landscaping in the increasingly hot and dry West.
What we promote with the UC Landscape Plant Irrigation Trials, or UCLPIT, is gardening with plants that are suited to their environment without the need for fertilizers, pesticides, or excessive amounts of water. Plants that make it through our trials with a high score can be counted on to be beautiful, low maintenance, and low water users, our Blue Ribbon™ winners, or moderate water users, which we designate Happy Mediums™.
Lygeum spartum, false esparto grass. (Photo: Karrie Reid)Plants on trial
The unique thing about this trial is that plants are given several different irrigation treatments (high, moderate, or low) and evaluated for performance on each. 2 While other trials typically evaluate from 3 to 5 individuals of a new cultivar all under the same conditions, we evaluate 24, with 8 plants on each weather-based irrigation treatment.
Plants are placed in randomized complete blocks in the ground, established on regular water in the first year, and evaluated on the different irrigation levels in the second year. Monthly measurements and quality ratings give us a good picture of how the plants perform and whether there are differences caused by the amount of water they receive. This robust scientific method over two years means we can perform statistical analysis and determine with a good degree of certainty the actual water needs of a particular cultivar.
Looking at them for two years affords the opportunity to see how they handle the mild frost and strong breezes we receive in Davis. We can also assess what kind of maintenance they require to keep their good looks. We do provide winter pruning too many of our shrubs and most of the grasses, but we make a point not to be too “precious” about it; we are trying to think like a commercial landscaper and imitate what they would probably do. With over 500 plants in the ground, anything requiring more than annual trimming is just too much work! For instance, with groundcover roses, we take power hedge trimmers to them and just whack them back to a consistently small mound, without paying attention to outward-facing buds.
Low water use vs. drought tolerant
Drought tolerance really just means that a plant will survive without water for some period of time. However, there are plenty of these survivors that look hideous without regular water and are not desirable to the average gardener. Few people want a garden that appears to be barely hanging on to life.
To be good for sustainable landscaping, a plant must not just survive, but thrive and still be attractive on low or moderate water. So, while we are evaluating plants for water use, we are also looking at a variety of aesthetic and health parameters:
- Foliage quality: does it wilt or curl up in the midday sun? Is it healthy and uniform?
- Pest and disease damage: is it more or less susceptible based on water availability?
- Flowering period and abundance: is the bloom affected by water; is it a flash-in-the-pan or lackluster bloomer; or does it re-flower or flower over a long period of time?
- Vigor: does it languish or continue to grow?
- Visitation by pollinators and beneficial insects: is it providing added ecosystem benefits?
- Most importantly, the overall landscape appearance — the WOW factor: do I see this from across the field and think, “What is that plant?” It does a plant no good to be classified as a low-water user if no one wants to buy it.
Some surprises
One of the best things about plant trials is that they have the potential to shatter your preconceived ideas about plants. One of the most fascinating things to me has been just how many of the plants we have evaluated performed equally well on all irrigation treatments. This suggests that most people over-water or water too frequently. Our highest irrigation treatment is watered once a week during the middle of July and less often in the shade.
From a scientific standpoint, when plant growth is virtually identical on all irrigation treatments, it means that many genera have evolved the ability to grow only so much during a particular growing season, regardless of the availability of water. Additional water may actually be a disadvantage if not used. If the soil is heavy and water cannot drain below the root zone, it may set up an unhealthy root environment. The water is then not only wasted but detrimental.
My realization of the power of research to disprove our assumptions came in the very first trial where we evaluated San Diego sedge, Carex spissa. At that time, the current edition of Sunset Western Garden Book stated that it required “ample moisture”. Given that it was a riparian/bog species, that was a fair assumption. However, we showed that with one year of regular water for establishment, it was actually able to perform quite well on low water; plants that were irrigated only twice during the summer looked just as robust and healthy as those that received the high-water treatment. When you consider the fluctuating nature of California's water supply, the evolution of the ability to handle both inundation and drought seems quite advantageous, making Carex spissa an excellent choice for vegetated swales.
One of the critical things to bear in mind with new introductions is that plant breeding brings new genetics into known plant genera. While they are adding a flower color or leaf shape or plant size, there may be something hitchhiking along in the genome that alters previous water use habits for better or worse. By evaluating new plants under different irrigation regimes, we have revealed both sides of this equation. For example, we have seen both rose and butterfly bush cultivars that performed best on low water, while others required moderate or high for best performance. Clearly, we cannot assume that a new cultivar will have the same adaptations as previously-known varieties.
Open house
One of the ways we assess the appeal of these potential introductions to the market is by holding Open House ratings events three times a year: spring, summer, and fall. We invite landscape and nursery professionals and academics, garden writers, public agency personnel, and UC Master Gardeners to view the second-year plants undergoing irrigation treatments and rate a sample of them on a limited number of characteristics. We also invite feedback on favorite plants, plants they would use, and plants they dislike. We share this information with our cooperators who have entered the plants into the trials so they can make decisions about whether or not to advance plants to market, at least in our region.
Looking ahead
For the entire life of UCLPIT, grant funding has played a major role in allowing us to provide this program to the industry and the gardening public. Our most recent grant from the U.S. Dept. of Agriculture and the California Dept. of Food and Agriculture is allowing us to partner with academic colleagues at universities in Washington, Oregon, Utah, and Arizona to replicate our trials in their locations. They will work with industry partners in their regions to identify and evaluate plants appropriate to their sites.
Three years ago, we took the leap and replicated our trials for both sun and shade in Southern California at the UC South Coast Research and Extension Center (REC) in Irvine under the direction of Dr. Darren Haver. This allows us to evaluate plants in this very different climate zone and soil type (sandy loam).
Additionally, the REC uses reclaimed water. Since many parts of Southern California are now using reclaimed water for landscape use, it will be critical to know if potential introductions can tolerate it.
We know that the trend toward sustainable landscaping has spread across the country and believe that Step One is knowing which plants are regionally appropriate. We are excited about bringing the scientific rigor of our plant trials process to other regions and hope that wherever water availability is a factor, this model of plant evaluation becomes the norm. With so many beautiful plants in development and now available for the sustainable gardening model, we are thrilled to be part of the process that brings an ever-wider variety of new and exciting climate-appropriate plants to a garden center near you!
If you fit into the category of one of our Open House participants and would like to attend one of our events, please contact us for more information.
Visit the UC Landscape Plant Irrigation Trials website and Facebook page.
1 The UK Plant Breeding Sector and Innovation https://assets.publishing.service.gov.uk/government/uploads/system/uploads/attachment_data/file/552498/Plan t-breeders.pdf
2 For a more detailed description of our irrigation protocols, please visit our website: https://ucanr.edu/uclpit
This article was originally published on the Pacific Horticulture Society website.
