- Author: Michele Martinez
Seeds are ripe when they shake in the pod, are easily removed from the plant, and/or are turning dark in color.
-- from Seed Collection Guidelines for California Native Plant Species, Rancho Santa Ana Botanic Garden, by Michael Wall, Seed Conservation Manager
Fall is seed-gathering time in the mountains. Over the past few years, San Bernardino Master Gardeners have begun to highlight seed-sharing, both as part of the Master Gardener mission, and our service to communities. With its hub at Chino Basin Waterwise Community Center, in Montclair, the San Bernardino County Regional Seed Library (SBRSL) also has satellite libraries in Yucaipa and the San Bernardino Mountains. The mountains seed library, still in its infancy, was created with the idea of connecting mountain residents through a shared love of wild-scape gardening.
Native Seed Propagation Propagating native plants can be tricky, because special conditioning is sometimes required to mimic nature's processes. Some plants, for example, need weeks of cool weather before germinating. Others require fire. Some plants prefer being ingested by birds, bears or other critters. A process called stratification is needed for some varieties. This involves storing seeds in a damp, refrigerated environment (33 - 38°F) for 60-90 days, before they're ready to go into the soil. Other seeds require scarification, or the breaking down of husks by acid-washing, hot water baths, sandpaper rubs, or other processes. In talking with Master Gardeners I've heard both success stories, and mixed reviews when it comes to propagating native seeds. Master Gardener/ROWIA member Cori Edwards, of Crestline shared a plan to use pine needles as kindling over a container of fire-start seeds. Mountain gardeners' seed-germinating experiments can be off-beat and interesting, and they always make for good storytelling.
If you are hoping to collect and propagate native seeds, look to the advice of RSABG and the California Native Plants Society and follow some simple guidelines:
- identify plants first (if possible, use both common and Latin names)
- make a note of the conditions in which each plant thrives (what type of soil, sun, and other conditions do you find?)
- always have permission before harvesting seeds
- be sure there are plenty of seeds left on site – use the 5% rule
- do your research to know what special treatments may be needed (should I stratify, scarify, or just go ahead and sow?)
- share! (don't forget to pass on some seeds, along with tips on how to get them started)
Resources
San Bernardino County Regional Seed Library (SBRL Facebook Page) https://www.facebook.com/sbrseedlibrary/
Rancho Santa Ana Seed Conservation Project https://www.rsabg.org/conservation/seed-conservation
California Native Plants Society, “California Native Plant Propagation,” by Matt Teel, Jan, 2018 https://www.cnps.org/gardening/california-native-plant-propagation-4014
Heaps Peak Arboretum, Rim of the World Interpretive Association https://www.heapspeakarboretum.com/
Calflora http://www.calflora.org/
Calscape http://www.calscape.org/
- Author: Michele Martinez
Encouraging healthy bee populations has long been part of the Master Gardener mission. In our study of Integrated Pest Management (IPM), we learn that chemical pesticides can do harm to entire food chains, from plants to insects, and other wildlife. With bee colony health very much in the news, many gardeners are surprised to learn that in addition to the European honey bee, California is home to hundreds of species of native bees, many of whom reside in solitary nests, hidden in plain sight around our gardens. On a recent walk through a local apple grove, I was excited to identify four – maybe five types of native bee hovering in the blossoms alongside the honey bees. We know that plants and bees rely on one another for their existence. Recent studies published by the UC Cooperative Extension can help us recognize our native species, and help raise awareness about preserving bee habitats.
How do we identify native bees in the garden? The 2009 report Native Bees are a Rich Resource in Urban California Gardens presents findings of a UCANR study done in collaboration with the North American Pollinator Protection Campaign and the Xerces Society. Over three years, scientists surveyed bees in seven urban areas across the California, including La Cañada-Flintridge, near Pasadena. Of an estimated 1600 native species currently known in California, 60 to 80 species were observed, along with the plants that attract them. The study shows which native bees are likely to show up in our gardens.
Of the species counted, the most common was the ultra-green sweat bee (Agapostemon texanus). To spot this bee it's important to look closely. With its smooth green body and slender shape, the sweat bee can be mistaken for a fly. The photos from the UC study by Rollin Coville (©2009) show a female ultra-green sweat bee (above) and a male (below) as they feed on native blooms.
Another common visitor, the leafcutting bee (Megachile perihirta) has a distinctive mandible designed for chomping stems and leaves.
The digger bee (Anthropora edwardsii) is prevalent in Southern California and is specifically adapted to the tiny flowers of the native manzanita (photo at top of article) (Arctostaphylos sp.). Like many native bees, the digger bee is solitary. The female prefers dark quiet places to lay her eggs, and makes her nest in dead wood, or in the ground.
Unlike the male of most bee species, females have specially formed hind legs made for gathering pollen. During springtime's brief blooms, native bees can be seen going from flower to flower loaded up with the golden powder. This solitary bee (Svasta obliqua expurgata) is a muli-tasker, as she simultaneously sips nectar and collects pollen on a coneflower (Echinacea pupura).
The native bees to look for in our gardens this season include those counted in the study: mining bees (Andrena angustitarsata); digger bees (Anthrophora); and three bumblebee varieties (Bombus), California, black-tip and yellow-faced. Others bees found include carpenter bees (Ceratina); gray digger bees (Habropoda depressa) and long-horn digger bees (Melissodes), as well as squash bee (Peponapis pruinosa); cuckoo bees (Xeromelecta californica); large carpenter bees (Xylocopta tabaniformis incompletes); leafcutting bees (Megachile); mason bees (Osmia coloradensis); and the blue orchard bee (Osmia lignaria propinqua).
Learn More About Bees
The Xerces Society's The Citizen Scientist Pollinator Monitoring Guide was created to help communities as they survey pollinator populations at the local level. The user-friendly guide (see link, below) helps gardeners learn the basics about bees, identify different varieties, and track their activities, over time:
http://www.xerces.org/wp-content/uploads/2010/06/CA_CSM_guide.pdf
The UCANR publication, Native Bees are a Rich Resource in Urban California Gardens is available online. It details some of the native plants that attract native bees, and help them thrive (California Agriculture 63(3):113-120 (2009)):
http://calag.ucanr.edu/Archive/?article=ca.v063n03p113
Credits:
All photos are by Rollin Coville (© 2009), used by permission of the Regents of the University of California.
Information on Native Bees:
North American Pollinator Protection Campaign
The Xerces Society for Invertebrate Conservation
Getting to Know our Native Bees
- Author: Jim Downing
Soon after Van Butsic arrived in California in 2013 to join UC Agriculture and Natural Resources, he noticed a pattern. “Fire, water and weed are the three land-use issues that come up no matter who I talk to in this state,” he said. Fire and water were well-covered by UC and other researchers already. But cannabis looked to be an unexploited niche.
UCCE Assistant Specialist Van Butsic uses satellite imagery to analyze the environmental impacts of cannabis production.
So Butsic, a UC Cooperative Extension (UCCE) assistant specialist in land systems science in the UC Berkeley Department of Environmental Science, Policy and Management, decided to build part of his research portfolio around understanding the scope, intensity and landscape impacts of cannabis cultivation in California (a research paper from another area of his research, ecosystem service valuation, appears on page 81 of this issue).
While the environmental impacts of cannabis production have drawn substantial media attention, and though it is by many estimates the state's most valuable crop, data beyond anecdotes is scarce.
Butsic attacked the problem by visually analyzing satellite-based imagery, identifying remote plantations and greenhouses in Humboldt County and mapping them using GIS.
This approach required many hundreds of hours of manual inspection of satellite images, and one of the first challenges was figuring out how to do this labor-intensive work. It wasn't difficult to find UC Berkeley undergraduates interested in working for course credit. Nearly 25 students have now contributed to the project, and two (so far) have moved on to full-time GIS jobs after graduation. An anonymous nonprofit organization provided financial support for a part-time staff researcher and to purchase more recent high-resolution satellite data.
This series of satellite images shows the development of a greenhouse complex in a Humboldt County forest. Using satellite imagery in combination with GIS layers showing topopgraphy, watercourses, zoning and other variables, Butsic and his colleagues can characterize cannabis production sites in a variety of ways, such as average slope, proximity to streams, and whether they are located on land zoned for agriculture.
The team has built a GIS data layer for about half of Humboldt County's land area, identifying roughly 300,000 cannabis plants (equivalent to a wholesale value of perhaps $150 million) based on 2012 imagery, with an updated estimate now in the works. The data layer enables a variety of analyses — from the zoning of the land used by cannabis growers (only about a quarter of the 1,429 grows identified were on land zoned for agriculture); to the slope of cannabis production plots, a factor influencing erosion (almost a quarter are on very steep ground, with slope exceeding 30%); to proximity to salmon streams (more than 200 grows were found within 100 meters of critical habitat for steelhead and chinook salmon) (Butsic and Brenner 2016).
Butsic and his colleagues identified approximately 4,400 grow sites in their research. Five percent of those, including the site pictured above, were within 100 meters of salmon streams.
Butsic estimates the absolute volume of water used to irrigate cannabis to be fairly modest — on the order of a few thousand acre-feet. But that figure probably understates the habitat impact of water diversions; water is withdrawn from small watersheds during summer months when water is scarce, and some creeks are known to have been completely dewatered.
The information is helping to inform local debates. Humboldt County recently adopted an ordinance requiring all new cannabis grows to be developed on land zoned for agriculture (existing grows on nonagricultural land are grandfathered in). This policy raises concerns about rapid inflation of agricultural land, as cannabis growers bid up prices beyond what other farm or livestock operations can support. Butsic's work provides insights into the characteristics and geography of lands that are likely to be developed for cannabis production.
Forest fragmentation occurs when cannabis growers clear land and build roads to access their grow sites. The Butsic team's analysis indicates that 68% of grows were located more than 500 meters from developed roads.
Related to this issue, Butsic and several Humboldt County–based UCCE academics — County Director Yana Valachovic, Area Fire Advisor Lenya Quinn-Davidson, and Livestock and Natural Resources Advisor Jeffery Stackhouse — are currently surveying Humboldt County landowners about cannabis-related land use issues.
Butsic's next steps include continued mapping of cannabis production in California, with Mendocino County to be completed by the end of 2017. Given the uncertainty around federal restrictions on cannabis production under the Trump administration, Butsic said it's difficult to predict what the most essential research questions surrounding cannabis will be. Nonetheless, “by continuing to document on the ground patterns of cannabis production, we will be in a position to answer those questions,” he said.