- Author: Chris M. Webb
We hear often of exotics pests and invasive species. We know that plants, pests and disease can spread in many ways. We also know new problems arrive regularly – seemingly with increasing speed.
In the Ventura County UCCE office people often show up with samples of soil, plants, and insects. We would like to take this opportunity to remind people that moving these, and related items, across geographical borders (countries, states and counties) often require permits. Permits may even be required when working with government agencies. Not obtaining a permit when required can lead to unpleasant consequences including: regulatory action, fines, or loss of research funding.
To help protect yourself and reduce the spread of exotic and invasive species, please do not move samples across geographical borders without checking if a permit is required. UC ANR Safety Note #146, “Quarantined and Regulated Pest Permit Requirements” can help. It can be found at http://groups.ucanr.org/ehs/files/68310.pdf.
Other UC ANR safety topics can be found at http://groups.ucanr.org/ehs/Safety_Notes/.
- Author: Chris M. Webb
To protect water resources and comply with increasing regulation, greenhouse managers are wise to make changes to prevent pollutants, such as fertilizers, pesticides, and container media from ending up in surface and ground waters. One way to do this is to use vegetated buffers.
Vegetated buffers are areas or strips of land maintained in permanent vegetation to prevent erosion and improve water quality by trapping and treating contaminants. Vegetative buffers can also provide many other benefits such as increasing beneficial insects for biological control of crop pests and protecting streambanks. In addition, they can be used for green waste and secondary crop production.
Some examples include vegetated buffers are bioswales, vegetated filter strips, and constructed wetlands.
- A vegetated bioswale is a stormwater conveyance system that channels stormwater. This type of buffer system improves water quality by reducing flow velocity and increasing sedimentation, filtering pollutants, and allowing infiltration into the underlying soils.
- A filter strip is a band of vegetation that can be used between a greenhouse and a waterbody. The purpose of the filter strip is to slow runoff from the production area and trap sediment, fertilizers, and pesticides before they reach surface water.
- A constructed wetland is an artificial marsh or swamp for treating wastewater, controlling flood waters, and reducing erosion. In greenhouse production, they can be built to further remove pollutants in the effluent from a retention basin.
Although there are different types of vegetative buffer systems, most work in a similar manner. Runoff containing soluble nutrients and pesticides, and sediments with adsorbed pesticides, enters the buffer. Vegetation in the buffer slow surface flow and sediments drop out. Some water infiltrates into the root zone and subsoil, while the remainder becomes lateral subsurface flow. When the roots of buffer plants grow to sufficient depth, they intercept infiltrated water, taking up the soluble nutrients and pesticides. Pesticides adsorbed to soil particles become trapped in the root zone, and high soil organic matter provides conditions for denitrification and pesticide degradation.
Things to consider before constructing a vegetative buffer.
When planning and designing a vegetative buffer, it is best to consult a licensed engineer or the Natural Resources Conservation Service (NRCS). Buffers need to be designed and constructed to comply with all federal, state, and local laws and regulations.
Plant species that are used in buffers should be selected based on their adaptability and tolerance to site conditions. Check local information sources, such as the NRCS and Cooperative Extension, before making selections. Some points to consider are: cost, growth rate, potential of plant invasiveness if not using native plant species, and the ability to use the buffers for producing secondary crops. Growers who are interested in developing techniques to produce secondary crops in vegetative treatment systems should contact Cooperative Extension and the NRCS for guidance.
Planting should be timed so buffers are established prior to expected runoff. Maintenance of vegetative buffers is necessary to sustain buffer function and effectiveness.
The information above was extracted from a larger document, written by Ventura County Cooperative Extension Farm Advisor, Julie Newman. Please contact us if you would like to read the original document in its entirety.
- Author: Chris M. Webb
An interesting study looking at the water requirements of common landscape plants, as told by Ventura County UCCE Staff Research Associate Maren Mochizuki.
Plants used commonly in the California landscape may have different water requirements for growth and aesthetics depending on the location in which they are grown. One indicator of the amount of water a plant needs is the local evapotranspiration (ET), which is the loss of water to the atmosphere from the surface of plants and soil (evaporation) and from plant tissues via their pores or stomata (transpiration). More information on evapotranspiration can be found at the California Irrigation Management Information System (CIMIS) website at, http://wwwcimis.water.ca.gov/cimis/infoEtoOverview.jsp.
Evapotranspiration varies considerably with the weather and location. In studies conducted by UCCE researchers across the state, (north coast, north inland, south coast, and south desert climates) nine common landscape species including agapanthus, day lily, and star jasmine are being watered based on 80%, 60%, 40% and 20% of daily local ET measurements. In the south coast region watering has ranged from weekly during the summer for the 80% ET to never for the 20% treatment.
Here in the south coast, the project is being conducted by Jim Downer, Ventura County UCCE Farm Advisor; Don Hodel, Los Angeles County Environmental Horticulture Advisor; and Maren Mochizuki, Staff Research Associate. When starting the project they allowed the plants to establish first, watering all of them equally and now have measured clippings and rated their appearance for the past two years. They are currently analyzing the data gathered so far and will continue the study one more year. Check back soon for some preliminary results!
- Author: Chris M. Webb
Ventura County University of California Cooperative Extension (UCCE) is here to extend science-based research to people in our community. We do this in a variety of ways, one of which is newsletters.
Landscape Notes is written for people working in the commercial landscape industry. The last issue is all about establishing landscape trees. It is full of fabulous, practical information that will help establish healthy trees.
Clover Lines is a newsletter published for 4-H members and leaders in Ventura County. It contains events, activities, and opportunities for youth aged 5-19.
Topics in Subtropics is a combined effort by University of California Cooperative Extension Farm Advisors from many counties in the state. It emphasizes citrus and avocado, but also discusses the minor subtropicals. The last issue covered:
- Avocado Research in Ventura County
- Laurel Wilt Disease Conference and Tour in Florida and Georgia
- Managing Insecticide Resistance will be Key to the Future of Effective Citrus Pest Management
- Smart Sprayers Make Sense
Farm Water Quality News delivers the latest news on integrating environmental quality with crop production practices. The last issue covered:
- Regulatory Update
- Industry Update
- Technical Tips
- Research Update
UC Cooperative Extension Report is our department newsletter. This newsletter includes upcoming events, highlight summaries of research and outreach activities, interesting facts and more.
Santa Clara River Watershed Times covers topics vital to anyone who lives, works, and recreates in the Santa Clara River watershed, the largest river system in Southern California. An amazing amount of information is extended in this newsletter covering a wide range of issues, opportunities, regulations, and accomplishments in an easy to read format with great photos. Links for more information are scattered throughout.
Our newsletters can be found by clicking this link. Once there, you can read current and back issues. You can also sign up for email notification to let you know when a new issue has been posted.
- Author: Chris M. Webb
Ventura County UCCE Staff Research Associate, Maren Mochizuki, explains one of our ongoing environmental horticultural research projects.
Typically, a plant will tell you how deep to transplant it: look for color changes along its “collar” -- the area along the stem or trunk for woody plants, between the roots and branches/leaves -- indicating the soil line when the plant was still in its pot. When planting, however, it is easy for zealous landscapers and homeowners to bury plants past this line…does this adversely affect the growth of the plant?
We (Jim Downer, Ventura County UCCE Farm Advisor; Don Hodel Los Angeles County Environmental Horticulture Advisor; and Maren Mochizuki, Ventura County UCCE Staff Research Associate, are investigating the effect of planting depth on six common landscape species including nandina, privet, photinia, pittosporum, and two varieties of prostrate acacia. We planted each of them at grade, and 1, 2 and 4 inches below grade and are annually rating quality, measuring their length, width, and height, and weighing clippings to evaluate their growth for three years. We are currently in the second year of the study and are analyzing the data we have gathered so far. Check back soon for some preliminary results!