The Peat Report: A Case Against Canadian Peat Moss

The Peat Report: A Case Against Canadian Peat Moss

The theme of last summer’s Seeley Conference, floriculture’s environmental footprint, included a discussion on how sustainable peat is as a soil amendment. The discussion stemmed from part of a presentation highlighting the new Sustainable Sites Initiative created by the American Society of Landscape Architects, the Lady Bird Johnson Wildflower Center and the United States Botanical Garden.

The three organizations are teaming on the Sustainable Sites Initiative (SITES) to create voluntary national guidelines and performance benchmarks for sustainable land design, construction and maintenance practices. But two recommended requirements of the initiative–using peat-free planting media and avoiding sphagnum peat as a soil conditioner–sparked a debate at the Seeley Conference.

To further explain the requirements, as well as the reasons SITES drafted them, Greenhouse Grower tasked the SITES with sharing some perspective. We also asked Mark Elzinga, president of Elzinga & Hoeksema Greenhouses, to share his reaction to the requirements regarding peat and the role peat plays in his greenhouse operation. Both SITES, represented by Steve Windhager, and Elzinga participated in the 2010 Seeley Conference discussion.

To read Elzinga’s essay, “A Case For Canadian Peat Moss,. Below is SITES’ case against Canadian Peat Moss.

The use of sphagnum peat as a soil amendment was considered by the technical committees of the Sustainable Sites Initiative (SITES) in the development of the “Guidelines and Performance Benchmarks 2009,” available as a free download at Reference to peat occurs specifically in Prerequisite 7.2 (restore soils disturbed during construction) and credits 5.9 (support sustainable practices in plant production) and 7.3 (restore soils disturbed by previous development).

Based on this technical committee work, the Sustainable Sites Initiative does not consider the use of sphagnum peat to be sustainable, as it is non-renewable within a 50-year time span.

Why Peat Is Not Sustainable

While the rates of annual accumulation of peat in Canada on an annual basis do exceed the volume extracted for horticultural purposes, this does not make this harvest sustainable. Peat accumulates at a rate of 0.5 to 1 millimeters annually, and thus an area cannot recover from harvesting within a sustainable time frame. Even the Canadian Sphagnum Peat Moss Association concedes that in regard to peatland restoration, “the full natural capital of the pristine bog [will not return] within any normative human timeline measurement.”

Peatlands are critical sinks for carbon and its extraction increases greenhouse gas emissions, covering only 3 percent of the world’s surface area but providing for 30 percent of all carbon stored in the soil. While extraction of peat for horticultural purposes currently only represents a small portion of total greenhouse gas emissions, harvesting peat does contribute to climate change.

One researcher has pointed out that because carbon dioxide (CO2) emissions from harvested, cutover peatlands are approximately three times greater than the emissions from natural sites, the loss of only 5 percent of Canadian peatlands–whether for horticultural extraction or some other cause–will result in Canadian peatlands being converted from a net carbon sink to a net source of CO2.

In addition, rising temperatures associated with global warming could significantly impact Canadian peatlands and trigger a feedback loop that would greatly increase peatland degradation and greenhouse gas emissions from them.

Abandoned, cutover peatlands rarely return to functional peatland ecosystems post-extraction because the physical and hydrological conditions required for sphagnum re-establishment have been eliminated in most cases. These degraded, cutover peatlands then become long-term, persistent sources of CO2 emissions. Thus, restoration of cutover peatlands is preferred to their abandonment, and it is possible to return a degraded peatland from a CO2 source to a carbon sink within three to five years–although a six- to 10-year time frame may also apply.

Continuing advances in extraction and restoration techniques may further reduce greenhouse gas emissions associated with horticultural extraction and facilitate more rapid and robust restoration.  However, intact, non-degraded peatlands sequester carbon at a greater rate than restored peatlands and disturbance associated with peat extraction irrevocably alters peatland ecology despite restoration.

In addition, negative consequences associated with peatland restoration, such as increases in phosphorus leaching from the rewetting of peat surfaces, are possible. And restoration will not regenerate peat stores at a rate that would permit sustainable extraction.

Therefore, while restoration of cutover peatlands is far preferable to their abandonment, there are significant environmental costs associated with cutover peatlands irrespective of restoration.

Climate Change Implications

Finally, climate change associated with greenhouse gas emissions is expected to bring hotter, drier conditions. By lowering existing groundwater levels, climate change can upset the delicate balance in peatland ecology between carbon sequestration and greenhouse gas emission, transforming many peatlands from net carbon sinks into net sources of CO2.

Canadian peatlands in the subarctic and boreal wetland regions, such as the Hudson Bay Lowlands, the Mackenzie River Valley region and the northern parts of Alberta and Manitoba, are most likely to be affected.

Researchers have calculated that climate change will impact 60 percent of the total area of Canadian peatlands and 51 percent of the organic carbon sequestered. In addition, greenhouse gas emissions from peatlands triggered by climate change could create a feedback loop that could raise temperatures still further and accelerate peatland degradation.

While additional research needs to be done to evaluate climate change’s impact on peatlands and carbon fluxes globally, the carbon sink-source relationship for Canadian peatlands is more likely to become a more significant contribution to climate change with continued harvesting.

Peat Moss Alternatives

Compliance with SITES credits that preclude the use of sphagnum peat moss is practical and achievable because alternatives do exist to the use of peat moss for soil restoration and as a medium for horticultural plant production. Compost, which the Soils Technical Subcommittee has judged to be a superior source of organic matter for soil restoration than peat moss, is widely, though not universally available, and typically at a much closer distance to a development site than a Canadian peatland. 

Alternatives to peat moss as a plant-growing medium, such as coir fiber and dust, wood fiber and bark, biosolids, bracken and compost, are available if not as extensively used.

It should also be noted that the efficacy of particular peat moss alternatives is relative to the use (i.e. plant propagation versus horticultural production) and to specific plants, and that the use of peat moss alternatives is in a learning phase as horticulturists become more familiar with them and understand the techniques and requirements needed to obtain best results. However, encouraging change and innovation that reasonably raises the bar for existing practices is consistent with SITES principles.

It is also important to note SITES is a voluntary set of guidelines for landscape sustainability aimed at market transformation and that certification is possible without achieving credits 5.9 or 7.3. SITES is striving to ensure that the built landscape is part of the solution for our global environmental problems, and we believe avoiding the use of peat is an important part of achieving this goal.

About the author: Multiple people associated with the Sustainable Sites Initiative (SITES), including Steve Windhager, director of the Lady Bird Johnson Wildflower Center and SITES, produced this essay. SITES can be contacted at

Leave a Reply

2 comments on “The Peat Report: A Case Against Canadian Peat Moss

  1. The myth that man’s impact upon CO2 is impacting global temperatures is rapidly falling apart. Why commit an economic disaster? This myth is short lived. EX. The Chicago Carbon Exchange closed down while the getting was good.

  2. The myth that man’s impact upon CO2 is impacting global temperatures is rapidly falling apart. Why commit an economic disaster? This myth is short lived. EX. The Chicago Carbon Exchange closed down while the getting was good.

More From Media...
Bill Lewis grower manager at Delray Plants

August 31, 2015

Delray Plants Takes Preventative Approach To Pest Control With Biological Controls

The 300-acre nursery in Venus, Fla., has made biologicals its first line of control when dealing with pests.

Read More
Fred C. Gloeckner Foundation logo

August 31, 2015

Gloeckner Foundation Awards 15 Research Grants

The Fred C. Gloeckner Foundation recently awarded 15 grants totaling $149,776. Fred C. Gloeckner had a keen interest and firm resolve to facilitate innovation and improve practices in floriculture. It was this vision that inspired him to start The Fred C. Gloeckner Foundation, Inc. 55 years ago. Since the foundation’s inception, more than 66 institutions have been awarded grants for this purpose, and the foundation’s support of floriculture research has totaled $6,525,642. The following grants were recently awarded: $14,000 – Kansas State University, to study the effect of the entomopathogenic fungus, Beauveria bassiana and the rove beetle, Dalotia coriaria, in suppressing populations of the western flower thrips, Frankliniella occidentalis $12,264 – North Carolina State University, for expanding leaf tissue nutritional standards in bedding plants $12,000 – University of Florida, to illuminate Lilium floral fragrance $11,842 – Stephen F. Austin State University, for its herbaceous perennial species trial garden $10,000 – Iowa […]

Read More
Feature image The 2015 Perennial Plant Of The Year, Geranium x cantabrigiense ‘Biokovo.’

August 27, 2015

The Perennial Plant Association’s Regional Symposium Will Be This October In Dallas

The Perennial Plant Association plans to hold its Regional Symposium October 5 in Dallas, Texas, in conjunction with the All-America Selections/Home Garden Seed Association's Summer/Fall Summit held October 5 to 8.

Read More
Latest Stories
Bob’s Market and Greenhouses’ Ron Morris pours Stockosorb into the hopper for distribution on the conveyor line

August 13, 2015

Soil System Improves Growing And Sales

My father started our company 45 years ago growing bedding plants, mainly early season production and finished plants for our West Virginia market. It was in the early 1980s that we started growing earlier spring production and shipping materials to southern markets, and by the late 1980s, we also produced pansies for fall. We started using hydrogels when they first came on the market in the early 1990s and found that they really helped with our production by keeping plants healthier for these new markets. Over the years, we’ve grown to be a large young plant producer and have a sizable business growing finished plants in cell packs, 4 1/2-inch pots, 6-inch pots, gallon containers, hanging baskets, multiple sizes of large containers and large baskets for municipal use. Creating The Ideal Soil Mix With our old system, it took several workers to mix pre-made soil with slow-release fertilizers in cement […]

Read More

December 2, 2014

Grow-Tech Announces BioStrate, Its Newest Hydroponic Gr…

Grow-Tech LLC recently announced the release of BioStrate Felt, a biobased textile specifically engineered for the growing of hydroponic microgreens and baby salad greens.

Read More

November 18, 2014

7 New Media And Light Products For Greenhouse Productio…

New media and light products cover a broad sweep of growing conditions.

Read More
Oakland Nursery plantings in Columbus_featured

November 17, 2014

Oakland Nursery Simplifies Streetscape Plantings And Ma…

The outdoor decorative containers that Oakland Nursery plants and maintains in downtown Columbus, Ohio, enhance the look of the city’s buildings and streets and hinder vandalism.

Read More

October 27, 2014

Peat Moss May Be In Short Supply This Year

Adverse weather conditions in Canada have played havoc with the peat moss harvest.

Read More

September 24, 2014

Canadian Harvest Of Peat Moss Is Below Average For 2014

The harvest season has been challenging, according to the Canadian Sphagnum Peat Moss Association (CSPMA), with lower-than-expected harvest of peat moss across most production regions in Canada, due primarily to adverse weather conditions across the country.

Read More

July 23, 2014

Liming Requirements And pH Modification For Pine Wood C…

In the last of a four-article series highlighting the production and use of pine wood chips as aggregates in greenhouse substrates, the researchers found growers do not need to adjust their production practices when 20 percent pine wood chips are used as a perlite replacement.

Read More

May 14, 2014

How Pine Wood Chips In Substrates Affect Plant Growth R…

This is the second article of the four article series highlighting the production and use of pine wood chips as aggregates in greenhouse substrates.

Read More

April 3, 2014

The Processing And Properties Of Pine Wood Chips

In the first of a four article series highlighting the use of pine wood chips as alternative aggregates to perlite in greenhouse substrates, researchers from North Carolina State University discuss the processing and physical properties of pine wood chips.

Read More

April 3, 2014

Water And Media Are The Foundations Of Your Business: T…

Electrical conductivity (EC) and pH, as well as water alkalinity, have the biggest effects on nutrient availability. Learn how to keep track of them through three common methods for better monitoring in the greenhouse.

Read More
PlugEase from Acme Group

March 3, 2014

Acme Group Introduces PlugEase, A Line Of Recyclable Ag…

The Acme Group recently announced its new line of recyclable Agrifabrics and plant plug substrate, PlugEase. The products make recycling affordable for greenhouse growers, farmers and horticulturalists.

Read More
Emerald Coast Growers

February 26, 2014

Emerald Coast Growers Constructs New Soil Facility

Emerald Coast Growers has constructed a new, consolidated soil mixing facility to increase efficiency and allow for easier custom blending by crop.

Read More
Combination pH and EC meter. Photo courtesy of Hanna Instruments

February 5, 2014

Test Media pH And EC With The 2:1 Technique, Pour-Throu…

Avoid a buildup of soluble salts and create an environment most conducive to nutrient uptake with these three common media testing methods.

Read More
Fertiss Growing Medium from Oasis Grower Solutions

November 18, 2013

Three New Options For Growing Media

From special blends to mycorrhizae, here are some new options for growth media.

Read More

November 14, 2013

Growing Media: To Mix Or Not To Mix

Thinking about making your own growing mixes to lower costs? There are many things to consider before taking the plunge.

Read More
Berger Logo

November 1, 2013

Berger Acquires Beaver & Lafaille Peat Moss

Berger, a producer of growing mixes, has acquired Beaver Peat Moss & Lafaille Peat Moss, consolidating a long-standing relationship between the companies. The transaction is effective on November 1, 2013. Under the agreement, Serge Lafaille, Beaver & Lafaille Peat Moss’ president, will join Berger’s sales team in order to ensure an easy transition for his current customers. “I am proud to join Berger’s team; we have the same business and growing philosophy, as well as a relentless commitment to being close to our customers in order to offer them what they truly need,” Lafaille says. Berger and Beaver & Lafaille Peat Moss have been partners since 1986. “For Berger, this transaction is a natural evolution of the strong relationship we’ve created with Beaver & Lafaille Peat Moss throughout the past 27 years,” says Berger CEO Claudin Berger. Located in St-Modeste, Quebec, Berger provides growing media and peat moss to professional […]

Read More

August 19, 2013

Students Evaluate Bio Char In Soil

Horticulture students from Olds College in Alberta, Canada, are investigating the viability of using bio char as a soil additive for greenhouse-grown crops. The group includes Emily Stanley, Michael Templeton and Heather Hood. Olds has a very good horticulture program, and I graduated from the greenhouse program there in 1996. Because of my involvement in the program, the group approached me to be a mentor for the study. In this role, I had conference calls with the group every two weeks to discuss the status of the project and offer any insight from a professional grower’s perspective. Bio char is a product derived from a special burning process of organic matter with limited amounts of oxygen. This holds the carbon in the organic matter. When the process is finished, you have a bio char product that can be used as a soil amendment. The students conducted trials on tomatoes and […]

Read More

June 6, 2013

Pro-Mix Is Now On Social Media

Premier Tech Horticulture, which is among the North American leaders of peat moss-based growing media production and distribution, has recently announced the launch of its social media strategy, including the unveiling of its Pro-Mix Facebook, Twitter and YouTube pages for professional and amateur gardeners. Known as a customer-focused and market-driven company, Premier Tech Horticulture strongly believes that today, people are expecting constant interactive communication with brands. As a result, interacting and communicating with external audiences through both new and traditional media remain important elements. Now, with Pro-Mix, this dialogue will also take place online, via new social media platforms that are easy to access for everybody. “These Pro-Mix social media platforms (Twitter, Facebook, LinkedIn, Pinterest, blogs, wikis, YouTube, etc.) present us with unique opportunities to listen to our customers and stakeholders, but also to share with people our 20 years of experience, knowledge and expertise,” says Chantal Duchesneau, marketing and […]

Read More