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 www.sustainablesites.org/report. 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 info@sustainablesites.org.

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...
Basil_Persian-AAS2015_620x329

July 31, 2015

All-America Selections Promotes Garden-Fresh Cooking

All-America Selections (AAS) has stepped forward with another first when promoting AAS Winners, this time in the form of cooking videos using vegetables/edibles that have performed extremely well in the AAS Trials. These days, a love of gardening is directly related to a passion for cooking. Tying the two together is a natural when marketing joys of cooking with fresh vegetables from the garden and farm market. After 82 years of conducting trials where only the best performers are declared AAS Winners, the organization now has more than 325 individual varieties that have been “Tested Nationally & Proven Locally.” It is some of these many varieties that culinary storyteller, entertainer and horticulture industry veteran Jonathan Bardzik will use in a series of five videos demonstrating cooking techniques with AAS Winning herbs and vegetables. “I am excited to partner with All-America Selections to show people across the country that AAS Winners perform […]

Read More
Burpee Home Gardens Brand Adds Flowers

July 31, 2015

4 Reasons Retailers Snub National Brands

Greenhouse Grower’s lead editor, Laura Drotleff, and I got into a debate about why garden retailers, especially independent garden centers, snub marketing efforts from breeders and growers. She was very much on the breeders’ and growers’ side, expressing frustration about how limited retailers’ vision can be on the topic. I’ve reported on the garden retail side of the industry since 1998, about the same length of time Laura has reported on growers. I’ve heard a lot of retailer views on this, so allow me to share the most common reasons why retailers decline free marketing: Costs. While the marketing materials are free, and sometimes advertising, participating in these projects usually requires minimum orders. From a grower’s perspective, the minimum orders are reasonable. If garden stores promote a plant line, they need to have enough supplies to satisfy demand. From a retail perspective, if inventory reports show a plant line can […]

Read More
llan Armitage Syngenta Starcluster

July 30, 2015

Let’s Talk About Starflowers. Why Is Pentas Not More Popular?

It is good to talk about production techniques, performance results and then to see how our friends garden. Diversity of plant material has always been a strength in American garden centers, and we should never run out of plants to get people excited. However, perhaps people are tired of Petunias or Callas or Geraniums, but we will never run out of options to put in front of them. One plant that is often overlooked is Pentas, a fabulous summer crop for late spring sales. These are heat-tolerant plants, and growing them below 65°F in the greenhouse results in significant delay. Fertility should be at least 150ppm nitrogen, but avoid ammonia in the fertilizer. Plants are best grown at a somewhat higher pH than usual, between 6.4 to 6.8. For best presentation, pinch out the center bud. Side flowers will bloom together, and plants will walk off the shelf. Garden centers […]

Read More
Latest Stories

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

June 5, 2013

Webinar: Coir Chunk Media – A Good Choice For Lon…

Growing media manufacturers are looking for new components that can be added to their growing media to improve physical properties and address common problems that the grower and/or end user face. One such problem the homeowner experiences with peat-based growing medium in hanging baskets and long term-planters is that they are hard to re-wet with water after they have dried out. Join Horticulture Specialist Troy Buechel on Tuesday, June 11 at 2 p.m. Eastern, 11 a.m. Pacific for this informative webinar to learn how Premier Tech Horticulture is addressing this issue with a new growing medium called PRO-MIX HP-CC. This product contains a unique coir chunk that does not require a wetting agent to wet and helps to hold water while maintaining good air porosity. Find out how this unique product and ingredients can help reduce long-term wetting challenges for you and your customers. Also did you know that a chunk […]

Read More