Sustainable Horticulture

Changes Affecting Horticulture, Both Bad & Good

Posted by sustainable_hort on November 22, 2011  |  No Comments

It was May when I last posted anything. Doubling our farm, taking over as manager of our local farmers market, and unexpected contract work meant no time to write. I am sure you assumed this site died a quiet death like most sites. Ambition usually blinds bloggers to the reality of maintaining a site with original, fresh content. It is partly that…but; I wish it were only that.

Sadly, it is not. When I started this blog, the intent was to focus mainly on the nursery industry and the sustainable model I saw as a future option for growers. But, it is an industry going through radical change, and not a good one. I am working on a draft for an article discussing what has struck a vibrant, positive industry. I am seeing and experiencing it firsthand, on the rural back roads that were the heart of Oregon’s leading agricultural crop. It is a matter of survival for these growers, and not a time for taking chances with any innovation, let alone risking your present production system for one that is still being developed. More on this soon.

Still, as an organic produce grower with a horticultural degree, I see opportunities for those nurseries that can turn to more sustainable production. In the next few months I will update the “Can Nurseries be Sustainable” post (12/23/2009), including the rough tests I ran with several organic container mixes at a local nursery. The results were impressive enough that I want to see more work done in this direction.

And, this site will continue to discuss the innovative future uses of plants, particularly in urban/suburban areas. This includes the diverse “urban agriculture” movement that could change how much of our food is grown and even become a “job creator?”

But, it goes far beyond that! I have been involved in the green roof industry for five years, and, despite the current construction collapse, it is technology for the times. It is just one example of how plants are being used to solve environmental problems. Plants will be integrated into our lives in ways we have not even developed yet…just look at the urban food production skyscraper being proposed by Dr. Dickson Despommier. I will discuss his book, The Vertical Farm, soon…though I have my doubts.

Finally, though there are other sources to find general agricultural information, I will continue to comment on the limitations and negatives of large agribusiness. For instance, the expanding herbicide resistance issue has overwhelmed the promises of easy farming. Even the main stream ag press has acknowledged this, warning its readers that production will need to return to more complex systems. As usual, something that seems too good to be true, finally fails. A return to working with nature, instead of fighting it, will probably turn out to be the best economic investment farming can make.

Anyway, enough for this short post. If any of the above topics interest you, please keep tune. Its good to be back.

Natural Alternatives to Turf

Posted by sustainable_hort on February 25, 2011  |  No Comments

My recent post on replacing turf with an edible landscape attracted many comments, especially through Linkin. While I prefer the use of edibles, I certainly realize not everyone wants to tend a food garden.

Grasses and many natives are perfect replacements for the turf in a normal yard. This alternative uses grasses, both native and introduced, and other native flowers and shrubs, to create landscapes that mirror the natural surroundings.

Timber Press recently released three books that address the use and design features of grasses, native flowers, and other plants. The most direct is Designing with Grasses by Englishman Neil Lucas, an up-to-date look at how modern landscapes are using grasses in many situations. He introduces grasses as key landscaping choices to the general gardening audience, suggesting choices for wetland, prairie, desert, woodland and meadow designs. It also offers a plant profile section, and many other reference lists. While not an in-depth look at grasses, it provides a perfect starting point for those interested in native and natural landscapes.

A better known, US expert on grasses, John Greenlee (with Saxon Holt) has written a new book on his specialty, The American Meadow Garden. He started Greenlee Nursery in the early 1980’s, becoming one of the first recognized experts on grasses and their use in design. In 1992, he wrote one of the seminal early works on grasses, The Encyclopedia of Ornamental Grasses. Now, here he focuses on the grasses that create meadow gardens, discussing details of design, site preparation and many examples of finished designs. The plant selections are covered in a long section complete with design suggestions.

Finally, Lynn Steiner took a similar approach in her Prairie-Style Gardens, with an emphasis on the plants that work in a prairie setting. It also includes plant lists for specific site conditions, and plant profiles for many prairie-adapted species. While her designs are based on four major climate areas of the mid-US, the design approaches can be duplicated in many regions. She also moves well beyond the grasses, and includes many trees, small trees and shrubs, vines and flowers. These gardens seem to have more emphasis on attracting wildlife, and include xeriscaping designs. But, more important, like edible gardens, they replace high input turf with a much sustainable landscape.

Wasted Yards to Mini-Farms

Posted by sustainable_hort on February 2, 2011  |  No Comments

Urban gardening continues to be an expanding trend. We are seeing more and more turf areas being replaced by some type of landscape, often food oriented. This does not break my heart. I feel most small yards (turf) are useless and a waste of space. Now, I have no problem with a larger yard, one that is used by children, pets and families for outdoor activities. Play on!

But many urban yards are just small patches of grass that need to be mowed, watered and fertilized. Some homeowners have moved to “more natural” landscapes that often incorporate native shrubs and trees to draw the local birds and insects, while many also save water. These choices are a vast improvement over un-used turf space.

Meanwhile, vegetable gardening remains hot trend, one that is seeing increasing sales. All part of the “urban homesteading movement.” The more dedicated homesteaders have also added a “perennial food system” with fruit trees, berries, grapes, and herbs. Why? Mainly because people are becoming more aware of what real food is, and this is one way to change what they eat. More and more families are realizing that food gardens don’t take much more water and fertilizer than a yard, and can be good exercise, and might even be close to fun. Good way to teach biology too!

But, the first challenge with many of today’s suburban lots is space. The empty lots and surrounding open areas of my childhood have disappeared. Today’s homes (many McMansions) have very limited outdoor space available to grow foods. So, intensive, raised-bed plantings, and careful use of sun exposed walls, fences, etc., still allow families to raise a significant amount of food. It just takes careful planning and consistent care. Add container gardening to the mix, and almost any popular vegetable can be grown successfully.

So, how? Let’s start with classic Square Food Gardening, by Mel Bartholomew, written 30 years ago (his revised book is readily available). Then, I will follow up with several other-related books that cover similar territory. They are all aimed at helping get you started changing your yard into a small farm.

In the original Square Food Gardening, Bartholomew produced a basic gardening book that also happened to cover his engineer-based, grid-growing system. The recent book explains the system well. But, according to several review comments on Google, much of the earlier basic gardening information has disappeared. I guess most of that information is available in many forms, from many sources, so the current edition is based on more photographs and less text to cover the same ground (no pun intended). The basic idea is still very useful.

One Magic Square by Lolo Houbein is, in some ways, almost a direct copy of Bartholomew’s work, except that the author bases her plans on 3-foot squares. She comes from Australia, so she may not even be aware of his history in small space gardening in the U.S. Still, the idea is the same. Still, it definitely serves the same propose as the earlier work, and she supplies 30 different designs for squares that meet different crop desires. These are very helpful to those getting started with gardening, who’s limited horticultural knowledge make planning difficult, especially in the first few years.

Sugar Snaps and Strawberries (Timber Press) by Andrea Bellamy does not instruct gardeners to plant in grids, but to use the smaller spaces around any home to grow food. Her food production is a community gardening plot and her third story balcony. Bellamy runs the blog, www.heavypetal.com., which supports organic gardening, and her experience with limited space makes her information particularly useful to those urban/suburban homes with vey limited space. She manages to cover most of the basic growing information efficiently, with useful suggestions on the best varieties and planting schedules for nearly year-around growing. She also includes details on container gardening, which is “gardening” to more and more people. Bellamy’s work creates integrated, food landscapes that blend in more naturally while maximizing growing space.

If you are looking at gardening more from the chef viewpoint, check out another Timber Press book, The Kitchen Gardener’s Handbook, by Jennifer R. Bartley. This book provides similar growing information and designs, but the real focus is the end products…the many recipes that use seasonal vegetables and fruits. As more cooks learn to use new vegetables and desire fresh ingredients, a home kitchen garden will probably be the focus of any landscape that replaces turf.

Finally, books with ambitious plans and growing information are useful to those getting started. But, does it really work? Can our neighbor’s yards become small farms? Edible Estates…Attack on the Front Lawn (Metropolis Books) edited by Fritz Haeg, with essays by food writers such as Michael Polland and Rosalind Creasy, take the issue head on. This is not a gardening guide, but an inspirational showcase of actual front lawns that have made the transition to “farm” successfully. Eight yards are examined, with design plans and step-by-step photos of the actual landscaping process.

Once you start this process, my advice is to take it slow and have a sense of humor. To keep you going, read Manny Howard’s My Empire of Dirt (Scribner), subtitled “A Cautionary Tale,” He seemed to run into an inordinate set of problems (it would discourage many beginners), but takes it all with a slightly dark sense of humor. There are a number of these autobiographical records of “becoming a farmer or urban homesteader” on the market today, but few work at this level of humor.

This whole trend is morphing, especially for young adults and young families, into a new homesteading movement…a reclaiming of the urban environment. It moves well beyond just having a small, kitchen garden to creating landscapes that more mimic the natural surroundings. It includes shrubs and trees that provide food, added diversity to draw beneficial insects and birds, trap and re-use rain water, adding chickens, rabbits and other small animals, composting, etc., etc. A visually strong introduction to this concept comes from the wonderful DK Press. Titled Self Sufficiency for the 21st Century, this larger format book runs through all the main activities that fall under this general heading. Written by Dick and James Strawbridge (co-hosts of UK television series It’s Not Easy Being Green), it is packed with how-to sections on building a home, energy and waste, growing food, animal husbandry, and many traditional home kitchen, natural medicine and craft skills, all aimed at living as far off the grid as a family might get in the urban environment. Most readers will probably only start with a few of the book’s actions, but it will give anyone a solid, visual introduction to this topic. I just love DK’s approach to making their books so visual and clear. When I travel, I use their city books because they, again, are visual. So, if you are dreaming of urban homesteading, study this book and read Howard’s view of the reality, and you might be ready to start.

COMING NEXT: The New Lawn, Part II: But, not all homeowners are interested or willing to make their lawn into a farm. No problem. There are many other options to the traditional lawns. The high maintenance turf can be replaced by more natural landscape spaces that mirror the surrounding environment. The post will cover some more recent releases that look at alternative landscapes.

Monrovia Falters…Industry Feels the Tremors

Posted by sustainable_hort on February 2, 2011  |  No Comments

Monrovia’s recent sales woes may indicate that a new marketing message is needed to revive a shell-shocked consumer.

I now look back at my years working for the Oregon nursery industry and realize it may have been a Golden Age for wholesale plant growers. The state’s sales skyrocketed over several decades from few hundred million to nearly one billion. Then it all collapsed. As the housing market dropped, so did landscape plant sales. Then, almost all commercial work stopped abruptly. Architectural firms shrank over night. This ripple hit the plant industry, especially the growers, and we have seen numerous growers go under or move into other horticultural crops. Sales this spring will probably improve slightly, but not enough to save many growers.

Monrovia has represented the peak of nursery industry production and marketing. Yet, like any industrial designed production systems, the operating costs are substantial. The company created new plants, led the “branding” effort (a marketing strategy that I always thought was over-sold), and used the garden centers to provide an effective distribution/sales platform. Now, with sales down drastically again, the company has been forced (by the banks) start selling “non-branded” plants to Home Depot to force sales. This obviously undercuts a basic part of their marketing/branding strategy of selling only to the independent garden centers. It has also created some severe comments from their customers.

But, it is not all their fault. All the quality products and clever marketing cannot “create” markets if there is, in this case, very little building going on. Add to this the panicked consumer…a one-two punch that has not just Monrovia but an entire industry on the ropes.

There are a few bright spots. Some narrow niche producers are keeping their sales at least even. Greenhouse operations that concentrate on annuals and especially vegetables are surviving. There was actually shortage last year of organic vegetable starts. Food costs, food safety concerns and a desire for better taste/nutrition are all driving this home garden trend. (See the next post on the urban homesteading movement.) A complimentary trend uses permaculture techniques to add native plants and create more plant diversity to draw beneficial wildlife.

But, the more general ornamental plant growers will need another marketing hook to push up sales. I propose turning to the strength of plants to provide a better, less polluting environment and lower energy use. I like to call the many uses of plants to improve our water and air a new “plant technology.” Sell plants because they provide solutions, not because they “decorate” our world. It is an old idea really. There is adequate research and successful examples to get consumers to look at plants, not as a “discretionary” expense, but necessary to improve one’s home and life. This “message” will sell better in the new consumer economy, one that is moving away from the wild spending of the last two decades.

Trees for CO2 Sequestration?

Posted by sustainable_hort on April 14, 2010  |  No Comments

(This is the first part of a two-part post on trees and CO2 sequestration, which looks at whether trees actually play a positive role. The second part will discuss the actual trees we should be using for this perceived benefit)

Trees can play an important, positive role in helping control the amount of carbon dioxide (CO2) in the atmosphere by absorbing that key greenhouse gas. The process, called “sequestration,” uses a tree’s photosynthesis to convert the problematic greenhouse gas to cellulose and oxygen.

As this concept has become more widely accepted and, as researchers continue to document trees’ benefits, it may expand market for some nursery crops. But, is all this excitement warranted, or do some recent questions contradict the enthusiasm?

What We Need to Know
The crucial questions at this stage become “does sequestration really work,” and if so, “which trees are most efficient at sequestration?” Research continues to delve into varietal and climate issues that affect how well a specific tree will capture CO2.

“We can certainly argue that trees, when they absorb CO2, buy us a period of sequestration,” said David Nowak, researcher at SUNY-CESF, Syracuse, New York.

But, Nowak, who has lead several major sequestration studies, points out there are many variables that need to be studied, including climate effects, tree species and age, and even the general maintenance issues.

“These all can impact the effectiveness of a tree to sequester CO2,” he said.

Other research has pointed out some distinct differences based on climate. In fact, recent computer models are even speculating that non-tropical trees might even increase planet temperatures.

But, planting trees in [any] climate is better than not. So, how does it work and what does research indicate as the best options for using trees to reduce atmospheric CO2?

What is Sequestration?…Removal of Air Pollutants
Air pollution can be reduced dramatically when plants take up CO2 and many airborne particles through their leaf stomata. Some other gases are removed by the plant leaf and stem surfaces. Gases absorbed by the plant stomata later diffuse into intercellular spaces. They then are absorbed and react with water films to form acids, or they react with inner-leaf surfaces. Some particles can be absorbed into the tree, though most particles that are intercepted are retained on the plant surface.

Some polluting particles may return to the air during transpiration or be washed off by rain. Later, the leaf and twigs may drop off the to the ground and start to decompose. This also releases some of the CO2 back, which offsets some of the early gains. Consequently, vegetation remains only a temporary site for retaining many atmospheric particles.

Benefits of Trees
Plant-It 2020 uses a ‘scientific estimate’ to develop the following statistics based upon the tree species, soil conditions and tree-planting methodology,

Their research indicated that 600 trees in the tropics would fill one acre, which could sequester up to 15 tons of CO2 annually. Other statistics include 40 trees (common varieties) will sequester one ton of CO2 each year; and that one million trees covering 1,667 acres could capture 25,000 tons of CO2 annually.

Research in major metropolitan areas showed the urban forests could have an impact. It was reported by David J. Nowak in “The Effects of Urban Trees on Air Quality” showed that in 1994, trees in New York City removed an estimated 1,821 metric tons (t) of air pollution at an estimated value to society of $9.5 million.

His research showed that while New York’s urban forests removed pollution more than Atlanta’s (1,196 t; $6.5 million) and Baltimore (499 t; $2.7 million), but pollution removal per square meter of canopy cover was similar among these cities (New York: 13.7g/m2/yr; Baltimore: 12.2 g/m2/yr; Atlanta: 10.6 g/m2/yr). These standardized pollution removal rates differ among cities according to the amount of air pollution, length of in-leaf season, precipitation, and other meteorological variables. Nowak’s work noted that large healthy trees (greater than 77 cm) annually remove about 70 times more air pollution (1.4 kg/yr) than small healthy trees (less than 8 cm in diameter) at 0.02 kg/yr.

His 2002 work matched earlier research regarding total CO2 sequestered within the US. Total carbon storage by urban trees in the coterminous United States is estimated at 700 million tons. These data correspond with previous analyses that estimated national carbon storage by urban trees as between 350 and 750 million tons and between 600 and 900 million tons. Carbon storage by urban trees nationally is only 4.4% of the estimated 15,900 million tons stored in trees in USA non-urban forest ecosystems. The estimated carbon storage by urban trees in USA is equivalent to the amount of carbon emitted from USA population in about 5.5 months based on average per capita emission rates.

The research reported that “urban forests in the north central, northeast, south central and southeast regions of the USA store and sequester the most carbon, with average carbon storage per hectare greatest in southeast, north central, northeast and Pacific northwest regions, respectively. The national average urban forest carbon storage density is 25.1 t/ha, compared with 53.5 t/ha in forest stands.”

He felt this data could be used to help assess the actual and potential role of urban forests in reducing atmospheric carbon dioxide, a dominant greenhouse gas.

Nowak’s research report stated the following:
“Air quality improvement in New York City due to pollution removal by trees during daytime of the in-leaf season averaged 0.47% for particulate matter, 0.45% for ozone, 0.43% for sulfur dioxide, 0.30% for nitrogen dioxide, and 0.002% for carbon monoxide. Air quality improves with 2 increased percent tree cover and decreased mixing-layer heights. In urban areas with 100% tree cover (i.e., contiguous forest stands), short-term improvements in air quality (one hour) from pollution removal by trees were as high as 15% for ozone, 14% for sulfur dioxide, 13% for particulate matter, 8% for nitrogen dioxide, and 0.05% for carbon monoxide.”

Meanwhile, www.plantit2020.org, has summarized recent forestry science studies in carbon sequestration related to trees, including the following:

The U.S. Forest Service estimates that all the forests in the United States combined sequestered a net of approximately 309 million tons of carbon per year from 1952 to 1992, offsetting approximately 25% of U.S. human-caused emissions of carbon during that period.

The US Forest Service also feels that large diameter; long-lived, leafy trees are more beneficial in regards to carbon sequestration. For example, they point to the fact that Atlanta’s 9 million-plus (mostly mature, broad-leafed) trees absorb about twice as much as Calgary, Canada nearly 12 million trees (many conifers).

They also noted that tree species is a strong determining factor regarding carbon sequestration, which vary by species in their rate of storing carbon, though research is still needed.
But, as a counter action, trees also vary in how many and how much harmful volatile organic compounds (VOC’s) they emit. One common example is isoprene, which produces the greenhouse gas ozone.

So, the best tree species is one that rapidly sequesters carbon but does not register high outputs of VOC’s. Long-lived trees (those living more than 50 years) are preferred by the Forest Service for carbon sequestration as dead trees rot – releasing all of the carbon that has been stored. US Forest Service recommends the following species for the United States…American basswood, dogwood, Eastern white pine, Eastern red cedar, gray birch, red maple and river birch.

Nowak does point out that the placement of trees actually has more impact that sequestration.
“The bigger impact comes from planting a tree in the proper location where it can provide cooling for buildings,” he said. “Just by preventing the added CO2 being emitted during air conditioning, trees can have four times the impact they have in sequestration.”

So, there are many functions to consider to maximize a tree’s impact on the environment, he cautioned.

Tropical Versus Temperate Zones
Another study, lead by Lawrence Livermore National Lab, indicated that trees planted closer to the equator sequester more carbon than those planted far to the North. Why this might have happened is still unclear. Some expert speculated that Southern tree species are often larger, long-lived, leafy trees compared to northern species.

Their computer models seem to confirm this observation. They built a model to determine the impact on temperatures forests have in different parts of the planet.

They focused on three key factors in their analysis:
• Forests can cool the planet by absorbing the greenhouse gas carbon dioxide during photosynthesis.
• They can also cool the planet by evaporating water to the atmosphere and increasing cloudiness; a deck of white clouds reflects incoming solar radiation straight back out into space.
• But, trees might also have a warming effect. They are dark colored, absorb sunlight and hold heat near ground level

“Our study shows that tropical forests are very beneficial to the climate because they take up carbon and increase cloudiness, which in turn helps cool the planet,” explained Dr. Bala, an author on the Livermore study.

So, the further you move from the equator, the more these gains are eroded she stated. The team’s modeling predicts trees planted in mid- and high-latitude locations could cause a net warming of a few degrees within a hundred years.

“The darkening of the surface by new forest canopies in the high-latitude boreal regions allows absorption of more sunlight that warm the surface,” Dr Baal said.

Counter Views
But, despite the general excitement over planting trees, no, literally planting forests as a solution to global warming, has hit some speed bumps recently.

In addition to the Livermore computer model concerns, two other recent papers in the scientific literature raised questions about the benefits of terrestrial carbon sinks. One paper, by Frank Keppler, Max Planck Institute, discovered that plants emit significant amounts of methane, which is a potent greenhouse gas, which traps heat much more efficiently than CO2.

Another study, by Robert Jackson, Duke University, found that plantations could reduce stream flow and increase salinization of soils to a greater extent than previously recognized. It looked at existing conversions and showed that the growing trees had larger water demands than crops or pastures “dramatically decreased stream flow within a few years of planting,” the authors wrote.

They also found that water use within existing tree plantations of all ages resulted in average stream flow reductions of 38 percent. Losses increased as the trees age, and “13 percent of streams dried up completely for at least one year,” the study said.

Overall, the tree farming used about 20 percent more rainwater, the study estimated. So, additional tree planting for carbon mitigation could have large impacts on nation’s water resources. This is ore of an issue in nations that net less than 30 percent of their total annual supplies of fresh water from rain, the authors predicted.

This has lead to experts some questioning the overall tree planting strategy, but others view this speculation as overblown.
Nowak also cautioned that urban tree management practices could diminish the net effects of urban trees on atmospheric C02. Activities used to maintain vegetation structure and health (e.g. from chain saws, trucks, chippers, etc.) emit carbon via fossil fuel combustion. Thus, too much maintenance could cause urban forest ecosystems to become net emitters of carbon unless secondary carbon reductions (e.g. energy conservation) or limiting of decomposition via long term carbon storage (e.g. wood products, landfills) can be accomplished to offset the maintenance carbon emissions

“Carbon released through tree management activities needs to be accounted for to calculate the net effect of urban forestry on atmospheric carbon dioxide,” he said.

He argues that unless there are secondary carbon reductions (e.g., energy conservation) or limiting of decomposition via long-term carbon storage (e.g., wood products, landfills), urban forests lose much of the sequestration gains. This, in turn, affects the species composition and tree maintenance activities chosen for an urban forest.

Some Conclusions
So, where does all this leave with trees and their effects on CO2 sequestration?

To maximize the net benefits of urban forestry on atmospheric carbon dioxide, Nowak wrote that urban forest managers should focus on the following:
• Planting long-lived, low-maintenance, moderate to fast-growing species that are large at maturity and matched to site conditions;
• Using maintenance activities that increase tree survival and longevity;
• Minimizing fossil-fuel use related to management and maintenance activities;
• Using wood from removed trees to delay decomposition or decrease the need for energy from fossil-fuel-based power plants (e.g., develop long term wood products; burn wood to heat residences); and
• Planting trees in energy-conserving locations.

This was summarized clearly by Greg McPherson in a Arbor Age article “Urban Tree Planting and Greenhouse Gas Reductions.”

He wrote that…”The climate benefits of trees in mid-latitude cities are not an illusion, although they certainly feel good. Reductions in atmospheric carbon dioxide are achieved directly through sequestration and indirectly through emission reductions. Still, planting trees in cities should not be touted as a panacea to global warming. It is one of many complementary bridging strategies, and it is one that can be implemented immediately. Moreover, tree planting projects provide myriad other social, environmental, and economic benefits that make communities better places to live.”

Thus, while CO2 absorption can be positive, putting the right tree in the right place remains critical to optimizing its benefits and minimizing conflicts with other aspects of the urban infrastructure.

Next part…coming soon. We will look at where trees work best, which trees might be the best, and include a long list of references on this topic. See you soon.

What Is Sustainable Horticulture?

Posted by sustainable_hort on March 24, 2010  |  No Comments

This is a quick thank you to all that have checked this blog and made so many positive comments. And more…a short view of where we are headed.

This blog was started to document, explain, revise, suggest and predict where the wide world of horticulture can honestly to create systems to grow plants that do not depend on petroleum based inputs (which at some point become scarce or at least much more expensive), but finds closed systems to supply those inputs. No one is saying it is easy, it still needs work and research, but natural systems are being identified. We just need to rethink some obvious biology, especially relating to soil, and how it has worked “sustainably” for millions of years.

Definitions are tricky…and “sustainability” is seems to be the rule in this case. There are many definitions, the majority of which tend to be bent to service those defining it. But, after reading numerous definitions, it seems to boil down creating ways to grow plants that will without harming workers or future generations later. Many include the definition of “environmental health, economic profitability, and social and economic equity.” This must mean “we must meet the needs of the present without compromising the ability of future generations to meet their own needs.” So, “stewardship” requires “maintaining or enhancing this vital resource base (soils, water and closed inputs) forever.”

Certain food and ornamental products have identified with this “sustainable” vision. More than identified, they have built businesses, created organic fertilizers and pesticides, established networks and distribution systems that are a first stage in creating a more sustainable horticulture. It might even lead to a more sustainable agriculture…a different conversation.

Even Miracle Grow, not the most organic product in the world, is now selling two soil amendment products. These miracle products, which the company promotes as containing “organic” components, promise healthy soils that “grow plants twice as large.” The company has recognized the concept, along with much of agriculture, that healthy soil is the literal and environmental foundation of sustainable horticulture, whether in farms or landscapes.

So, this blog first focuses on ornamental plant production. I am working with a wholesale grower in the wonderful Willamette Valley, Oregon, where plants like to grow. It is one of the main reasons I live here today. We are seeing if a grower of shrubs and trees can work towards a sustainable sustainability…one that works economically long term. A key phrase in this sentence is “long term.” And it may mean growing not the largest plant, but the healthiest plant. This is not just speculation, but has a background, starting with the works of Sir Alfred Howard and William Albrecht, and continuing today with the Rodale organization, the Leopold Center for Sustainable Agriculture, and ATTRA. I suggest reading New Opportunities in Sustainable Landscapes and Can Nurseries be Sustainable? on this blog, and investigating the references. Let’s keep the discussion going.

At the same time, this site will point to new uses of plants from green roofs and walls, to storm water control with green streets, to growing food on empty rooftops and in our neighborhoods. We find cities planting more trees, urban agriculture sneaking into backyards and along cities edges, plants being used to clean water and air, and cool our heat islands. This is all positive and needs to be recognized as an important environmental strategy, one that can also create jobs. Obviously, without plants, there is no food or air, there is no “us.” So, it becomes important to recognize and utilize plants at every level we can.

Finally, this discussion site will lead to the introduction and testing of organic input products here in the Northwest (with application nationally), and we will be providing some of those products through this site and with advertising support. This all works toward my focus, helping horticultural growers (both food and ornamental) move, step by step, to a sustainable future while still providing the planet with plants.

And, a main test site will be our organic produce operation, 19th Street Farms. Since the links on this template are not working right, just type in “www.19thstreetfarms.com/blog/” to get to the site. I will use this blog for other content, but the site will busy in summer. It is also our CAS/Farmers Market site where we are continually talking with our customers. So look under specific categories for your favorite topic.

MORE COMING SOON…

Plant Lists for Bioswales and Rain Gardens

Posted by sustainable_hort on March 18, 2010  |  No Comments

This post, as promised, presents a quick overview of the various plants used in bioswale and rain garden environments. It is not as simple as just throwing a few water tolerant plants in the ground. Careful plant choice and placement play key roles in successful “wet” landscapes.

Plant selection for these projects is driven by several key factors including the following:

Obviously, the basic site conditions play a huge role. Factors like sun exposure, soil depth, physical and chemical properties and moisture holding capacity can vary, so need to be understood for successful plantings.

What is the intended function of the project? For many projects, the landscape’s performance, including infiltration, pollutant removal and evapotranspiration rate will determine its success.
But, there can also be safety issues, which may require added protection such as surrounding hedges. Finally, aesthetics play a role since many working landscapes sit in neighborhoods and other public areas. While visible, they can seen as an amenity, and even provide some recreational opportunities.

No landscape is going to be maintenance free; so long term needs should be studied. This is one area where the plant material choice can have dramatically different cost impacts.
Finally, recognize each site’s natural water regime. Check the depth, frequency and duration of soil saturation, which will vary daily, seasonally or annually. For instance, Portland, Oregon, is considered a “wet” climate, but the summer is extremely dry. Plants in these urban, constructed wetland must survive extreme variations. A similar garden in Atlanta, Georgia, or Columbus, Ohio, would get significant summer rain.

Actually every rain garden or bioswale has its own “zones” that have different requirements, according to the Virginia Department of Forestry’s Rain Gardens Technical Guide. The guide points out that the center, and deepest, part of the garden best grows the very wet to wet-loving plants. Meanwhile, the middle of the garden’s side takes wet to dry plants, while the upper rim takes drier types of vegetation.

The guide lists other factors affecting the choice of the plants for rain gardens:
• Decide on objectives, such which wildlife you want to attract, then decide on the varieties you would plant to attract those species. [Refer to reference list below]
• The rain garden’s location affects use of fruit-bearing plants and trees, since if it is near the driveway or walkway, it could create messes and maintenance issues. Trees next to a power line or too close to a house are not good choices.
• If the bioswale are near enough to receive runoff from a road that gets chemical treatments for ice in winter, choose plants that tolerant salt.
And then there is actual selection of species and varieties…and a common question, should we plant natives compared to introduced, commercial varieties?

Why Native Plants?
The majority of the web sites that deal with bioswales or rain gardens are also now recommending using natives. So, why is this the accepted trend?

As Withrow-Robison and Johnson point out in the OSU publication Selecting Native Plant Materials for Restoration Projects, “selecting appropriate plant materials for restoration projects helps make any of these projects more successful. They state that, “‘appropriate’ means choosing species that are suitable for the site, are grown from locally adapted sources, and have a solid genetic composition.” In many cases, this leads to using native species.

So, what is a “native plant?” Most definitions say a “native plant” occurs naturally or has existed for many years in an area, and they can be trees, flowers, grasses or any other plants. “Local adapted sources” can mean those plants have adapted to a very limited range, living in unusual environments, under very harsh climates, or growing in unique soil conditions. Yet, while some had a very limited range, many others live in diverse areas or easily adapt to different surroundings.

So, to summarize the strengths of using natives in bioswales and rain gardens.
• First, native plants are better adapted to the local climate. Once planted and established, do tend not to need extra water or fertilizer.
• Secondly, many are deep rooted, allowing them to survive droughts. This is especially important in the Northwest, where the normal wet weather can disappear for several months during the summer months.
• Third, native plants provide habitat and food for native wildlife and, are thus very attractive to the diverse native bees, butterflies, beetles and birds, all important pollinators.

These plants, which include many wildflowers, sedges, rushes, ferns, shrubs and small trees, grow on the edges of natural wetland, also have root systems that enhance infiltration, moisture redistribution, and diverse microbial populations involved in biofiltration.

A key point to remember is that rain gardens, unlike a water garden, will be dry most of the time. Plant selection should include those that tolerate short periods of inundation, but not require constant standing water. In areas that will have moist, well-drained soil, select plants with moderate moisture requirements. For drier sites like the edge of your rain garden, plant species with low or moderate moisture requirements.
Meanwhile, any perennial plants need to be hardy in your growing zone.

Each region has growers of appropriate native and related plants for rain gardens and bioswales.

In fact, some successful growers will collect seed their own seed from the local area. For example, one Oregon native plant producer has collected seed for plants such as snowberry (Symphoricarpos albus), salmonberry (Rubus spectabilis) and twinberry (Lonicera involucrate) in the immediate area, using on a couple of mother plants for each. Another grower collects all her Pacific dogwood (Cornus nuttallii) from two trees growing at a nearby park.
See references below for several recommendation lists.

These three urban plant technologies are just part of a wider set of alternative Best Management Practices (BMPs). Many are simple, practical designs, but provide effective storm water management. Some even add aesthetic enhancements to the urban, suburban, and rural landscapes. They can be cost effective to build while providing long-term sustainability for city infrastructure and conservation of a city’s water resources. These include filter strips, grassed swale, green roof, and infiltration basin, planters and trenches.

So, as the cost savings are identified, the demand for specific plant materials should increase. At this point, the trend seems to be moving toward regionalized, native plant materials. Since there are a number of operations already propagating this niche, they may have the best opportunity to benefit from this particular green movement.

References:

The following references are available online and have been updated relatively recently, so they contain more current research and data regarding various plant choices.

• Rain Gardens Technical Guide Virginia Department of Forestry
www.dof.virginia.gov/mgt/resources/pub-Rain-Garden-Tech-Guide_2008-05.pdf

• Selecting Native Plant Materials for Restoration Projects by B. Withrow-Robinson and R. Johnson, OSU publication EM 8885-E, November 2006.
extension.oregonstate.edu/catalog/pdf/em/em8885-e.pdf

• Plants for Stormwater Design
www.wildflower2.org
Native plant database and suppliers directory for North America.

• Rain Gardens Technical Guide – Virginia Department of Forestry
Central Office
900 Natural Resources Drive, Suite 800, Charlottesville, Virginia 22903
www.dof.virginia.gov
Phone: (434) 977-6555 – Fax: (434) 296-2369
VDOF P00127; 05/2008

• Brooklyn Botanic Gardens, Rain Garden Plants.
This web site offers regionalized lists of suggested plants for rain gardens. Not as extensive as other sites, its easy to use breakdown is a good starting place in identifying plants for an effective design palette. www.bbg.org/gar2/topics/design/2004sp_raingardens.html

• 10,000 Rain Gardens (www.rainkc.com) has an extensive site that features a diverse list of plants for rain garden situations. It also has a search feature that allows criteria selection from five categories, so a nursery could focus first on what it is already growing, expand to closely related varieties, and then look for new opportunities that would fit within existing production systems.

• Bluestem Services: (www.bluestemservices.com) Has numerous plants lists, but two feature nearly 100 plants for rain gardens and wetlands.

Trees Prove Valuable in Several Ways

Posted by sustainable_hort on February 21, 2010  |  No Comments

Several posts ago I mentioned several confirmed environmental benefits of planting trees. The good news keeps coming.

First, a study from the east coast indicates that trees are growing faster, probably due to the increase in CO2. The study, published in The Proceedings of the National Academy of Sciences, concentrated on hardwood stands in Maryland that were representative of east coast tree populations. The work showed trees were growing an additional two tons of plant material per acre annually as the CO2 levels have increased 12% in the last 22 years. This is another indication that plants may yet save the planet. Gaia in action.

Then, a recent article in the Oregonian (Portland, Oregon) cited a recent research study that estimated the added value of having full size trees in a yard was $7000! Of course, as the article points out, there are a lot of added costs. And, your neighbor that shares that shade tree also gains value from it presence…without the costs. I tended to focus more on the fact that trees improve land values, and not the article’s concern that the “neighbor” was not sharing the upkeep costs…only getting the value. This is definitely a positive study for those supporting more trees in our urban/suburban settings. Make them fruit trees and they are even more valuable.

Finally, another book to recommend…Between Earth and Sky by Nalini M. Nadkarni. Not another descriptive collection of trees for yards, this one specifically discusses trees and their “intimate connection” to us. It goes beyond economic value into a more spiritual connection that is demonstrated by our long relationship with trees.

A Landscaper Looks at Sustainability

Posted by sustainable_hort on February 4, 2010  |  No Comments

In my recent post , New Opportunities in Sustainable Landscapes, the discussion centered on new landscape directions for the industry. This post looks at how one landscape firm looks at creating a different landscape, one focused on sounder environmental principles.

“Sustainability does mean change and that’s the reason we are hearing about it all the time,” said David Sandrock, owner of Sustainable Landscapes for the Pacific Northwest, Corvallis, Oregon.
“But, it is an opportunity,” he said during his presentation at last November’s OLCA Expo. “People are looking to us for solutions.”
Sandrock said that “sustainability” is based on several key concepts.
The former Oregon State University professor said the first concept is often used as a definition of sustainability.
“Sustainable action is development that meets the needs of the present without compromising the ability of future generations to meet their needs,” he offered.
This, in turn, takes intelligent resource planning, he said, and added that this movement emerged in response to human misbehavior.
“These actions move toward landscapes that we can depend on, not landscapes that depend on us,” he concluded. “It will require a return to the art and science of horticulture.”

Trees Saving the Planet?

Posted by sustainable_hort on February 1, 2010  |  No Comments

The New York Times is reporting that a new research report, being published in today’s issue of The Proceedings of the National Academy of Sciences, indicates that trees are growing faster, perhaps in response to the atmosphere’s added carbon dioxide. (http://www.nytimes.com/2010/02/02/science/earth/02trees.html)
This relates to my last three posts that discussed the increasing role plants will play in solving climate change issues. This plant and planetary reaction seems to confirm some of the Gaia theories of James Lovelock, see site: (http://en.wikipedia.org/wiki/Gaia_hypothesis).
So, does this mean that the cooler temperate regions might actually see increased growth of not only the natural vegetation, but agricultural crops as well? There are already early olive ventures in the Willamette Valley of Oregon, moving up from California. Will Oregon start growing oranges next? Or maybe avocados!
Follow this site as we investigate, synthesize and report on the new “plant technologies,” including green roofs, green walls, bioswales, higher respirating plant varieties, plant site placement, etc.