by Guest Ranter Ken Druse
"Do
you know what sphagnum peat moss is? Do you know what it's used for?"
I
asked several gardeners these questions after a lecture I gave in Connecticut a
while back. Here are the results of my informal poll. Fifteen out of 20 people did not know what
peat moss was, including the manager of a garden center. (He thought it was the
same as homemade compost.) Perhaps more surprisingly, seven out of the 20
people did not know what peat moss is supposed to be used for (although they
all bought it). One person said her husband spread it on their lawn. Most of
the gardeners suggested that peat moss was a mulch to put on top of the soil.
Peat
moss is the partially decomposed remains of formerly living sphagnum moss from
bogs. Because it's nearly impossible to
rewet once it's dried, it repels water and makes a terrible surface mulch. As a soil amendment, which is what the baled product is mostly sold for,
peat moss is also a poor choice. It
breaks down too fast, compressing and squeezing air out of the soil, creating
an unhealthy condition for plant roots.
Peat moss can be a useful growing medium for containers, however, when lightened
with a drainage material like perlite.
The biggest problem with peat moss is that it's environmentally bankrupt.
Peat
moss is mined, which involves scraping off the top layer of living sphagnum
moss. The sphagnum peat bog above the mined product is a habitat for plants
like sundews, butterwort and bog rosemary, as well as rare and endangered
animals like dragonflies, frogs and birds, not to mention the living moss
itself. Despite manufacturers' claims that the bogs are easy to restore, the
delicate community that inhabits the bog cannot be quickly re-established. Yes,
peat moss is a renewable resource, but it can take hundreds to thousands of
years to form.
Like
all precious wetlands, peat bogs purify
fresh air and even mitigate flood damage.
And
there are archeological reasons to preserve peat bogs. In the acidic moss below the living layer,
wooden artifacts of people who lived long ago survive, even the remains of the
people themselves. CO2 is also preserved
– trapped in the moss, but released into the air when mined. In fact, peat bogs store about 10% of all
fixed carbon.In
the U.S., peat moss is almost exclusively used by the horticulture industry.
40,000 acres of sphagnum are currently being harvested in Canada, with 90% of the
product destined for gardens in the U.S.
In the U.K., where peat moss is burned as fuel, as well, nearly 94% of
the lowland bogs have been altered or completely destroyed due to harvesting. And most of our peat is shipped hundreds of
miles, often when it’s wet and heavy, which adds further to the fuel required
for shipping.
Many
conservationists, gardeners, and wetlands scientists in these countries have
recommended a boycott of peat. The Royal Horticultural Society hopes for a 90%
reduction by 2010. Areas in Ireland have already banned the harvesting of peat
moss altogether.
Producers
in both Canada and the United States maintain that they never cut sphagnum
faster than it grows, and leave behind enough peat to ensure regeneration. The
Canadian Sphagnum Peat Moss Association claims that peat-moss operations keep
the bogs from being drained for development, that five to ten years after
harvesting, the bog will be a "functioning wetland" again, and that
after 25 years, 90 percent of the original flora will grow back. I have my
doubts. Some wetlands scientists point out that a managed bog lacks the biodiversity of the original bog.
In
a development at the center of the gardening world, Monrovia Growers has just
introduced a new line of bagged “soil” which contains peat moss. That's according to their press release about
the products; the word “peat” never appears on their website.
Though
gardeners seem to have been programmed to buy peat and are as loyal to the
product as some car-buyers used to be about their beloved Pontiacs, there's
simply no need to use it. Chopped leaves make a much better and more attractive
mulch, and compost is superior as a soil amendment.
If
only more Americans could be encouraged to compost. If only corporations started their own
composting facilities, and if only more municipalities got serious about
composting.
In
addition to homemade compost, I use coir, a byproduct of the coconut processing
industry. (Here's one reliable source.)
This formerly discarded material can be shipped completely dehydrated – very
lightweight – which reduces its energy requirements for transpor
ting.
What do
other organic gardeners think about peat moss, coir, or about Monrovia’s new
products?
This week on the radio show "Ken Druse Real Dirt," Ken interviews Tovah Martin. It'll be available tomorrow right here.
Canadian peat bog photo credit.
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