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Going Green In The Greenhouse

On first glance they looked like various sizes of peat pots but they were actually Cow Pots.

The greenhouse industry is not known for being particularly environmentally friendly. Most of the containers used in plant production are non-recyclable plastic and most of the planting medium used is peat based. The extensive use of plastics, derived from the world’s finite supply of petroleum, and peat moss, which takes thousands of years to be replenished once it is harvested from bogs, has earned the greenhouse industry a reputation for being anything but environmentally friendly. For an avid gardener like me who frequents greenhouses and hauls home innumerable plants from them each year, I find this fact rather disconcerting.

I believe gardening to be a generally good thing for the environment – the more vegetables and flowers we grow ourselves, the less damage is done to the environment by large commercial growers’ use of chemicals and the fewer greenhouse gases are spewed into the environment while transporting fresh produce long distances. Growing gardens also contributes to the number of plants on the earth which absorb some of the carbon dioxide from the atmosphere. So, although I believe my hobby is basically good for the environment, if I can shop at greenhouses which are trying practices that are less harmful to the environment, I will be happy to do so.

I visited The Trestle Greenhouse in Rivers, Manitoba, this spring and the owner, Eleanor Beever, was explaining to me about the new type of containers in which many of her plants where growing. On first glance they looked like various sizes of peat pots but they were actually Cow Pots. She and her husband and business partner, Marlin, had discovered a company in Connecticut that manufactures plant pots out of composted cattle manure. She likes how the plants perform in these containers and is delighted that the product is more environmentally friendly than the more commonly used plastic ones.

Cow Pots must be kept dry until they are used and they have a short shelf life once planted and watered – around 12 weeks. They gradually disintegrate over time and the big advantage they have is that the plants can be planted right into the ground without removing the pots. By planting-out time the roots of the plants will have grown through the sides and bottom of each container and once it is buried in the soil it will continue to compost and simply disintegrate into the soil. Eleanor had the pots in trays so that the roots emerging from the pots were not exposed to the air. The Cow Pots are treated in the manufacturing process to eliminate pathogens and odour.

Several companies also are in the process of developing planting mixes from composted and processed cattle manure with some encouraging results. Although there is some debate about whether there is any shortage of peat moss and whether the resource is indeed threatened, some people believe that it is a finite resource which takes centuries to renew itself and therefore is endangered by the current level of exploitation. Perhaps in the near future there will be renewable resources such as animal manure that can be used instead of peat. Products have been developed using coconut husk fibre, but because it has to be shipped from tropical countries it is debatable whether its carbon footprint is any smaller than that of peat moss. It is an encouraging sign to see some industry members making an effort to become more environmentally friendly. In the meantime one thing all gardeners can do is reuse – or find a gardener who can – all of the containers we accumulate each spring. Eventually, however, most will end up in the landfill. – Albert Parsons writes from

Minnedosa, Manitoba

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