UCCE Master Gardeners of San Bernardino County
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UCCE Master Gardeners of San Bernardino County

Posts Tagged: plants

Benefits of Plants to People, Communities, and Urban Urban Ecosystems: Part 1

Benefits of Plants to People, Communities and Urban Ecosystems:  Part 1:

The link between horticulture and health and well-being and to urban ecosystems has been scientifically documented for centuries. In 1812, psychiatrist, professor, and Declaration of Independence signer Dr. Benjamin Rush reported in his book “Medical Inquiries and Observations, Upon the Diseases of the Mind” (Rush 1812) that patients “digging in the dirt”

fared better than their non-gardener counterparts. Since then, hundreds of scientific studies have been published documenting benefits of active (e.g. gardening/landscaping) and passive (e.g. viewing nature through a window, taking a walk in a park) interactions between people and plants and the value of plants in urban ecosystems.

Benefits related to cognitive functioning, societal and community health, and mental health are summarized below. Ecosystem and physical health benefits from interacting with nature will be discussed in next month's blog.

Improved Cognitive Functioning

Several studies link participation in gardening activities to enhanced cognitive functioning (Bratman et al. 2012; Dadvand et al. 2015; Kuo et al. 2021; Ohly et al. 2016; Park et al. 2019; Stevenson et al. 2018; Wells 2000. Research conducted by Kuo and Sullivan (2001) and Mayer et al. (2009) found that exposure to nature in urban settings can enhance attention span, working memory, and concentration. Both youth and adults who participate in greening and gardening projects were also found to have higher cognitive functioning in the areas of short and long term memory, focus and concentration (Dadvand et al. 2015; Markevych et al. 2019; Matsuoka 2010; Meuwese et al. 2021; Park et al. 2019; Stevenson et al. 2018) and reduced symptoms of ADHD (Faber Taylor and Kuo (2011).

Other studies summarized in a literature review (Williams and Dixon 2013) found that kindergarten and middle school students who participated in school gardening activities linked to classroom learning in biology, nutrition, mathematics, and other subjects earned higher grades and attained greater academic achievement than non-participants. A recent study linked high tree canopy coverage on school grounds with higher achievement scores in math and reading in middle school students across a wide range of socioeconomic and ethnic backgrounds (Kuo et al. 2021). The experiential (hands-on) learning elements of school gardens can also bridge the gap between traditional and non-traditional learners due to its multi-sensory nature (Kolb and Kolb 2005). School gardens play an especially important academic role among elementary-aged youth from low-wealth inner city communities exposed to outdoor experiential learning that was previously lacking (Dyg et al. 2020; Kuo et al. 2021; Ray et al. 2016; Williams et al. 2013). However, Hoover et al. (2021) found that successful, sustainable school gardens require strong administrative and district support in addition to enthusiasm and support from parents and teachers.

Enhancement of Societal and Community Health

Urban greening projects that remediate vacant land, landscape streets and neighborhoods, create community gardens, and improve the health of wetlands and undeveloped natural environments can build community cohesiveness, neighborhood bonding, and mutual community pride (Diamant and Waterhouse 2010; Draper 2010; Glover et al. 2005; Hartwig and Mason 2016; Kuo and Sullivan 2001; Moyer et al. 2019; Neo and Chua 2017; Saldivar-Tanaka and Krasny 2004). With blighted uncared-for vacant lots comprising nearly 15% of total land area of U.S. cities (Branas et al. 2018) these opportunities are substantial. Results also indicate that gardening and urban greening projects unite people from different cultural and ethnic backgrounds who enjoy growing and sharing produce from their native regions (Agustina and Beilin 2012; Baker 2004; Cruz-Piedrahita et al. 2020; Dyg et al. 2016; Hartwig and Mason 2016; Teig 2009). Building a sense of community through social engagement, celebrations, and communal meals has also been found to benefit both gardeners and non-gardener participants (Ober et al. 2008).

Well-designed and maintained urban green spaces not only bring people together, but can reduce crime, gun violence and enhance the safety and cohesiveness of urban neighborhoods, as summarized in several literature reviews (Bogar and Byer 2016: Mancus and Campbell 2018; Shepley et al. 2019). Some of the strongest links reported in the literature involve crime reduction in vegetated and well maintained urban neighborhoods and walkways (Branas et al. 2018; Demotto 2006; Garvin et al. 2013; Locke et al. 2017) and a reduction in gun violence in neighborhoods with green spaces including trees (Branas et al. 2018; Kondo 2017; Schertz et al. 2021; Wolfe et al. 2012). One study found that community-based greening projects that vegetated vacant lots was an effective strategy to improve neighborhood safety, resulting in a nearly 40% decrease in violent crime (Heinze et al. 2018). It should be noted that other researchers (Groff and McCord 2012) found a higher incidence of opportunistic crime in high tree canopy covered areas, perhaps due to concealed illegal activities. Another study found that actively participating in community greening projects from design through implementation and maintenance can result in a sense of accomplishment and satisfaction (Murphy-Dunning 2009). Neighbors caring for urban green spaces together also tend to spend more time conversing and building important social relationships than do non-participants (Peters et al. 2010).

Improved Mental Health 

Multiple literature reviews link interactions with nature to improved mental health in both youth and adults (Bowler et al. 2010; Clatworthy et al. 2013; Coventry et al. 2021; Cruz-Piedrahita et. al. 2020; De Vries et al. 2003; Tillmann et al. 2018) in studies conducted in parks, gardens, urban green spaces, and even shopping malls. The restorative impact of simply viewing plants has also been widely studied. Walking through a park and even viewing a natural scene through a window can lead to a sense of well-being, restfulness, reflection, and reduced mental fatigue (Shanahan et al. 2019). More recently, Dzhambov et al. (2020) found lower rates of depression in students homebound for long periods of time during the COVID-19 pandemic with views of plants (indoors and out) compared to students who lacked plant interactions. Bowler's (2010) literature review also highlighted strong associations for self-reported positive emotions and lower levels of anger and sadness in natural settings compared to non-natural settings. Interactions with nature can also reduce symptoms of depression and anxiety (Beyer et al. 2014; Gonzalez et al. 2010; Lee and Maheswaran 2011; Van den Berg and Custers 2011; Wilson and Christensen (2011).

Thompson Coon et al. (2011) reported that exercising outdoors in natural settings led to greater feelings of positivity and revitalization, less tension, anger, and depression compared to the same amount of exercise indoors. Other studies link gardening to feelings of peace and contentment (Meuwese et al. 2021; Shanahan et al. 2015; Shanahan et al. 2019). MacKerron and Mourato (2013) reported that individuals who interact with nature are often happier than those lacking this interaction and Ambrose et al. (2020) reported that home gardeners growing food crops experienced particularly high levels of happiness and meaningfulness. Bakolis et al. (2018) linked two elements of mental well-being (optimism and energy) to interactions with nature while Van den Berg and Clusters (2011) and Wood et al. (2016) found a link between engagement with nature and a reduction in stress. While White et al. (2019) determined that these benefits are maximized when individuals spend 120 minutes a week or more interacting with nature, shorter periods of exposure are also beneficial (Shanahan et al. 2016; Shanahan et al. 2019; White et al. 2019).

Other studies reported a link between growing food and a deepened sense of purpose (Tzoulas 2007; Wiesinger 2006). Digging in the soil can be a welcome distraction from busy lives laden with deadlines, traffic jams, and other everyday stressors. Focusing on the needs of plants, whether it be watering, fertilizing, harvesting or other tasks, can prove pleasantly distracting, providing time for reflection and even problem resolution (Capaldi et al. 2015; Meuwese et al. 2021; Stevenson et al. 2018). Several research papers report important positive roles that plants play related to mental health as impacts of climate change increase (Cryder et al. 2006; Dillman-Hasso et al. 2021; Doherty 2018; Fernandez et al. 2015) related to posttraumatic stress disorder (PTSD), major depressive disorder, stress, anxiety and others.

Literature Cited

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Posted on Thursday, November 4, 2021 at 6:53 AM
Focus Area Tags: Agriculture, Environment, Health, Yard & Garden

Benefits of Horticulture and Human Interactions

“To forget how to dig the earth and to tend the soil is to forget ourselves.” Mohandas K. Gandhi, World leader, political ethicist, lawyer

“Everything that slows us down and forces patience, everything that sets us back into the slow circles of nature, is a help. Gardening is an instrument of grace. ” May Sarton, Poet “

"May our heart's garden of awakening bloom with hundreds of flowers.” Thich Nhat Hanh, global spiritual leader and activist “If you have a garden and a library, you have everything you need.” Marcus Tullius Cicero, Roman philosopher

"The importance of encouraging our children in outdoor work with living plants is now recognized. It benefits the health, broadens the education, and gives a valuable training in industry and thrift. The great garden movement is sweeping over all America, and our present problem is to direct it and make it most profitable to the children in our schools and homes. — Van Evrie Kilpatrick, 1918, in “The Child's Food Garden”

As the above quotes so beautifully proclaim, interacting with nature, whether passively (viewing plants) or actively (gardening, etc.) offers many positive benefits. In fact, the link between horticulture and health and well-being has been scientifically documented for centuries. In 1812, psychiatrist, professor, and Declaration of Independence signer Dr. Benjamin Rush reported that patients participating in gardening activities had better mental health outcomes than non-gardening counterparts.

Many additional papers were published throughout the 1800's documenting benefits of active participation in gardening. More recently, positive links between simply viewing plants through a window or even on a television, movie, or exercise apparatus screen have been reported in peer-review journals. A groundbreaking study in this area was published in 1984 by environmental psychologist Robert Ulrich (Ulrich, 1984) who compared post-operative patients recovering from gall bladder surgery who had views of landscape plants to recovering patients who had the same surgery in the same facility with views of a brick wall. Patients with landscape views had fewer surgical complications, shorter hospital stays, required fewer analgesics, had better moods, and even fewer derogatory remarks by medical staff in their daily records.

Since 1984, dozens of other studies have documented similar positive outcomes resulting from both passive and active engagement with nature and plants. These include improved physical, mental and emotional health; environmental benefits; and community and societal benefits. Recent literature reviews that summarize these findings include:

- An overview of 77 peer-reviewed journal articles (Howarth, et. al., 2020) identified 35 positive outcomes linking physical and mental health and well-being to active and passive horticultural interactions. doi: https://10.1136/bmjopen-2020-036923

-A meta-analysis (Soga, 2016) of 22 studies identified several positive mental health outcomes related to gardening including mood, group cohesiveness, cooperation, pride, well-being, and more. https://doi.org/10.1016/j.pmedr.2016.11.007 -

An overview of 45 peer-review studies (Shepley, et. al., 2019) identified links between properly designed and maintained urban green spaces and crime, gun violence, and the overall safety and cohesiveness of low-wealth urban neighborhoods. https://doi.org/10.3390/ijerph16245119

- A review of 120 papers (Crus-Piedrahita, et. al., 2020) reported public health benefits from urban horticulture activities in the global North. Thirty-two papers had a specific focus on social cohesion and/or social capital. https://doi:10.1016/j.glt.2020.10.001

-Alizadeh (2019) synthesized research regarding the environmental benefits of urban plants, highlighting their vital roles in combating climate change, cooling urban heat islands, providing habitat, removing air and water pollutants, enhancing soil health, and more. https://www.researchgate.net/deref/https%3A%2F%2Fdoi.org%2F10.1108%2FIJCCSM-10-2017-0179

Enjoy your garden!  Enjoy a day in nature.


Posted on Saturday, October 2, 2021 at 9:24 AM
Focus Area Tags: Agriculture, Environment, Family, Food, Health, Natural Resources

California Invasive Species Action Week – Let’s work together to be better, do better, and grow better.

Words like 'invasive plants' or 'weeds' often have a negative connotation for a good reason. Both words describe plants growing where they are not wanted or welcome. Plants that have a propensity to spread quickly result in habitat loss for native plants, insects, birds, and other animals. This is incredibly destructive to our natural environment and the landscape that Californians love to call our own. 

Highway iceplant (Carpobrotus edulis) often forms deep mats covering large areas. Shallow, fibrous roots are produced at every node that is in contact with the soil. Highway iceplant has been widely planted for soil stabilization and landscaping, and is well known by most Californians for its succulent three-sided leaves via CAL-IPC.org

Fast spreading invasive plants can quickly and dramatically change a plant community from a diverse one to a monoculture. When these plant communities shift, wildlife loses food, water and shelter resources and are forced to move out or perish.

Unfortunately, this description is not an over-dramatization. As Californians, we must communicate frankly about the impact of invasive plants in our environment. This is an important issue that can easily grow out of control. One of the biggest challenges with invasive plants is that they oftentimes have desirable features, like beautiful flowers or a spreading habit that quickly covers a barren patch in a home landscape.

Mexican Feather Grass (Nasella or Stipa tenuissima) is popular in home landscapes because of its drought tolerance but it is invasive and produces tens of thousands of seeds.

Well-intentioned people have sold, purchased, propagated, and harvested plants that are known to be invasive. When done so knowingly, the gardener may use the excuse that they will watch the plant and not let it get out of control. Unfortunately, there is no way to monitor a plant that is distributed by wind, birds and other sources. It may be possible to monitor that your plant doesn't ‘escape' to the neighbor's garden but what about the seeds that blew off in the wind and established on a hillside two miles away?

Big Periwinkle (Vinca major)is rapidly spreading in most coastal counties, foothill woodlands, the Central Valley, and even desert areas. Big periwinkle has escaped from garden plantings, and lowers species diversity and disrupts native plant communities via www.cal-ipc.org.

Paying attention to signage and programs that identify invasive plants is an important part of caring for our environment. When questions about weeds and invasive plants arise, the UC Master Gardener Program is available locally to support good decisions and help us all be stewards of a healthy California.

Trained and certified volunteers utilize the vast network of information and expertise of the University of California to support gardeners and concerned citizens. You can reach your local county program online at mg.ucanr.edu/FindUs/.

It's Invasive Species Action Week – let's work together to be better, do better, and grow better. 

California Invasive Plant Resources: 

Spend your lunch learning about invasive species. Brought to you by UC Agriculture and Natural Resource and the California Invasive Plant Council, come hear from the experts about emerging tree pests, aquatic invasive species, and invasive weeds and fire.

Invasive Species Lunchtime Talks

  • Shot hole borers and other threats to California's trees (June 5, 12:10 - 1pm)
  • Quagga mussels, nutria and other threats to California's water bodies (June 6, 12:10 - 1pm)
  • Invasive plants and fire in California (June 7, 12:10 - 1pm)

Join from a PC, Mac, iPad, iPhone or Android device:
Please click this URL to join. https://ucanr.zoom.us/j/401190822
Or join by phone:
Dial(for higher quality, dial a number based on your current location):
US: +1 (646) 558-8656 or +1 (669)900-6833
Webinar ID: 401 190 822

Posted on Tuesday, June 5, 2018 at 9:26 AM
Focus Area Tags: Yard & Garden

Halloween Plants that will Scare the BOO out of you!

It's a scary time of year! Plants are amazing life forms, coming in a wide array of forms, shapes, and colors. Here are some of my favorite Halloween plants that are sure to scare the living daylights out of you!

Doll's Eyes (Actaea pachypoda)

Doll's eyes plants are not only poisonous but host eyeball-like berries that are highly toxic to humans but don't harm most birds. Unless you're visiting friends or relatives or vacationing in the Midwest or Northeast USA you may never set your own orbs on this plant!

Devil's Claw or Ram's Horn (Proboscidea louisianica)

This unfriendly looking species is native to the South Central USA and sports a unique horn-shaped pod. In addition to its attention-grabbing visual appeal, pigments contained in the pod are used for black dyes by several Native American tribes.

Bleeding Tooth Fungus (Hydellum peckii)

This startling-looking fungus oozes fake blood through minute pores. (The red goo is actually a result of guttation that forces water into the roots during osmosis.) Fortunately for Southern Californian's, it is found mostly in the Pacific Northwest and Europe living peaceably in a symbiosis with conifers.

White Ghosts or Indian Pipes (Monotropa uniflora)

Photo credit: Jay Sturner / Flickr

These eye-catching specimens have bright white droopy flowers reminiscent of ghosts found in spooky dark, dank basements. They hide in shady spots and live in a symbiotic relationship with a fungus in their roots providing food.

Happy Fall!

Posted on Monday, October 30, 2017 at 9:18 AM

Little Less Conversation, Little More Action (Please)

I saw Elvis today. 

Actually, he's quite the regular at Sustainable Conservation's San Francisco headquarters these days. More than a titan among musical icons “The King” has become a muse to the PlantRight team, especially this National Invasive Species Awareness Week . We love Elvis' “A Little Less Conversation” because it might as well be our theme song for actionable awareness. We can't guarantee you'll be dancing along by the end of this article, but we do guarantee providing you with a few awareness-raising resources, a deeper understanding of what's holding back the hold-outs from taking positive action, and most importantly what we can do about it.

PlantRight defines “actionable awareness” as what happens when individuals and businesses are made aware of an opportunity to be part of the solution to California's costly (economically and environmentally) invasive garden plant problem, and make a conscious decision to act.  Invasive plants (despite the fact that many are deceptively beautiful and drought resistant) outcompete native plants, alter soil chemistry, increase wildfire risk, clog our waterways and can severely compromise agricultural yields and real estate value. If that weren't enough, invasive species are the second greatest threat to biodiversity after human development.

Awareness of these facts alone will not fix any of these issues; however, add action to the mix and you have a proven formula for problem solving.  PlantRight's idea of problem solving is collaborating with the industry to voluntarily phase invasive plants out of the supply chain and replace them with high-quality (i.e. non-invasive) plants. Voila! Together we prevent new invasive garden plants from wreaking havoc on our wild lands and taxpayer wallets.

Invasive species are second greatest threat to biodiversity after guess who …?
A Little Less Conversation, a Little More Action Please

The fact that 50% of California's invasive plants are of horticultural origin (Bell et al. 2007) is a source of both conversation and dismay.  Yet from PlantRight's perspective this 50% is a great source of optimism because it's proof of a huge opportunity the nursery industry can play in preventing future invasive plant introductions. In past decades ornamental plant breeders and growers had little or no ability to predict a plant's invasive risk in a given region, and most invasions were well-intentioned accidents.  Lucky for us we finally have science-based plant risk evaluation tools to prevent new invasive plant introductions.   Not so lucky for us is that popular plants travel, and a delightful Dr. Jekyll plant in one region, may become a hideous Mr. Hyde plant and landscape transformer in a different region. It's about the right plant in the right place, but just where to begin, if we're to turn this talk into actionable awareness?

In the beginning there was lots of conversation and lots of listening sessions that Sustainable Conservation conducted with a diverse group of nursery industry stakeholders, from large ornamental growers, retail nurseries, plant scientists, trade associations and government agencies. University of California Agriculture and Natural Resources (UC ANR) has been part of this group from the start, providing academic expertise on weeds and calculating their risk. This group's official moniker is “California Horticultural Invasive Prevention,” but we prefer Cal-HIP.

With a couple years of listening and learning under our belts, and funding from Sustainable Conservation, the PlantRight program was ready for action: action   engaging the nursery industry in voluntarily phasing our invasive ornamental plants and promoting, in their place, non-invasive alternatives.

Our first order of business was to measure the scope of the problem and establish a baseline. Working closely with plant science experts to identify the most problematic invasive ornamental plants, and industry experts to identify non-invasive alternatives, we created our first PlantRight plant list. If you can measure it you can manage it, we like to say - to do this, we rely on an annual Spring Nursery Survey. Each spring, partner with UC Master Gardener volunteers to survey more than 200 nurseries and garden centers around the state, and in the process track the retail market for invasive garden plants in California.

Along with informing PlantRight's program strategy, the annual survey allows us to keep PlantRight's plant list manageable and up to date – we add new invaders and retire those that are largely phased out of the trade.  It is our program's calling card, and the starting point for conversations with prospective partners and skeptics, alike.  It has earned the enthusiastic support of California Certified Nursery Professionals (CCNPro), SaveOurWater, and more.

A Little Less Fight, a Little More Spark

Buying non-invasive means many things, including protecting native species, being good stewards of our beautiful open spaces and waterways, being fiscally responsible and preventing additional taxpayer dollars going to avoidable invasive plant eradication efforts.  Buying non-invasive plants is casting a vote for the kind of world you want to live in.

So, why on earth do people buy invasive plants in the first place? (Hint: One big reason has to do with what happens when you turn off the lights). Yep, people who purchased invasive plants were in the dark – they did not know. 

In 2013, we learned that the primary drivers behind consumer purchases of invasive plants are: 1) aesthetics – it looks good; and, 2) there was no information on the plant indicating “invasive.”  In other words the majority of invasive plant purchases (by consumers) are impulse purchases and would not have occurred had the plant been properly identified as “invasive.”

Photo credit: Susan Morrison
Nan Sterman, award winning garden writer and host of PBS' “A Growing Passion,” has her own answer to this vexing invasive plant question.  “It's about visual influence,” says Sterman.  “People tend to buy and plant what they see in their local gardens and landscapes. “ According to Sterman, these include the very people who religiously recycle, buy high-efficiency appliances, and drive electric cars, yet they can't imagine beautiful, drought tolerant plants posing environmental problems.  Nassella tenuissima, or Mexican feathergrass, is one such culprit that has been romancing many well-intentioned Californians.

Come On, Come On…Come On, Come On

Ready to channel your inner Elvis and tackle invasive garden plant problems in ways that make economic sense?  (Of course you are!)  Here are a few resources to empower more action in your community.

So this National Invasive Species Awareness Week we encourage you to crank up that volume and bust a move with the PlantRight community (blue suede shoes optional), knowing that YOU are driving actionable awareness…this week, this month and in the years ahead.

Thank you, thankyouverymuch.

Posted on Wednesday, February 24, 2016 at 1:40 PM
  • Author: Jan Merryweather, PlantRight
Tags: Invasive (2), Invasives (1), Pests (6), PlantRight (8), Plants (2)

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