TORONTO — National Organic Week is a chance for Canadians to learn more about how organic agriculture affects the environment.

The event, billed as the largest celebration of organic food, farming and products across the country, is set for Sept. 19-27. There will be farm and garden tours, workshops and tastings of organic food and drink. Local health food stores will be hosting activities.

Organic food is grown without pesticides, herbicides, hormones or antibiotics. To be labelled organic, domestic and imported items must meet all Canadian food regulations as well as additional organic standards and inspections, which also apply to handling.

Artificial colours, flavours, sweeteners, preservatives and many other aids and ingredients in processed foods are also forbidden in organic foods.

“It’s not like a natural label where anything can be labelled natural,” says Michelle Book, a holistic nutritionist at the Canadian Health Food Association. “In order to have the Canadian organic logo, food is verified by a third party and is guaranteed to have an organic content of at least 95 per cent or more.”

Canada is the fourth-largest market for organics in the world. The total number of farms in Canada has decreased by 17 per cent since 2001, but organic farms grew by 66.5 per cent, according to the Canada Organic Trade Association. There are more than 3,700 organic farms across the country.

For those deciding whether to eat organic fruits and vegetables, Book points to two lists published by the U.S.-based Environmental Working Group — Clean 15 and Dirty Dozen Plus.

“The Clean 15 are fruits and vegetables that you may not necessarily need to buy organic and the Dirty Dozen are those that tend to be more heavily sprayed with pesticides and herbicides and where you do want to go organic,” says Book.

The Clean 15 includes foods such as pineapples, corn, onions and sweet potatoes, while the Dirty Dozen Plus includes apples, strawberries, grapes, celery, peaches and spinach.

To minimize costs, Book suggests stocking up on items when they’re on sale and freezing them.

“Especially at this time of year when there’s such a bountiful harvest and all kinds of organic fresh fruits and vegetables, put them in the freezer so during the winter months when maybe they’re not as readily available and potentially a bit more costly you have them at hand.”

Clothing as well as personal care and cleaning products are also under the spotlight during National Organic Week, which is organized by the Canadian Health Food Association, Canadian Organic Growers and the Canadian Organic Trade Association.

To find out about events in your area, visit http://www.organicweek.ca.