Our resident gardening expert advises a reader on when and when not to use peat moss.
Recently I started a garden, and many books I've read recommend using peat moss to improve soil. I've heard that peat moss may be a nonrenewable resource, plus it's expensive. The less I spend, the more I save by growing my own vegetables. What do you recommend?
Avoid using large amounts as a soil amendment, but do use small amounts for seed-starting mixes. Here's why:
Over 10 million cubic yards of peat moss are harvested each year from bogs in Canada, plus another million or so from bogs in the northern United States. Those are big numbers, but because less than 1 percent of North American peat lands are currently being mined, peat bogs remain more plentiful here than in the British Isles, where harvesting has reduced peat acreage by nearly 80 percent. However, peat comes from such slow-growing, slow rotting plants that it typically takes 1,000 years for a bog to add 1 yard to its depth. Once harvested, peat bogs are changed forever.
Of equal concern are the environmental costs of the fuels used to harvest, process and then ship it long distances, which in your case is about 1,500 miles. That's a lot of greenhouse gas emissions produced to provide organic matter for outdoor beds. Compost, shredded leaves and grass clippings would do as well and are less expensive.Peat moss does have special characteristics that make it a better choice when used in small amounts as part of seed starting mixtures. It absorbs and holds 10 to 20 times its dry weight in water, and it is a very poor medium for various soilborne fungi, including those that cause seedling damping off. Beneficial bacteria can live in peat moss, so using small amounts of peat moss to start seeds indoors is a sound decision. Once seedlings grow big enough to transplant outdoors, compost makes a better soil amendment than peat because it contains a wealth of biological life-forms and a huge range of major and minor plant nutrients.