Organic

Abundant Life Seeds
Certified organic vegetable, flower, and herb seeds.
http://www.abundantlifeseeds.com/

Appalachian Seeds
North Carolina sellers of organic seeds for a variety of heirloom and open pollinated vegetables, herbs and flowers.
http://www.appalachianseeds.com/

Brother Nature
Specializing in organically grown, open pollinated flower, vegetable and herb seeds.
http://www.brothernature.ca

Ecogenesis Inc.
Canadian company selling seeds grown from publicly-owned genetic material. Variety descriptions, but does not clearly differentiate between conventionally grown and certified organic seed.
http://www.ecogenesis.ca/

Elixir Farm
Organic and biodynamically grown Chinese and North American medicinal plant seeds.
http://www.elixirfarm.com/

Genesis Seeds, Ltd.
Based in Israel, Genesis is a large producer of certified organic seeds of flowers, culinary herbs, medicinal herbs and vegetables.
http://www.genesisseeds.com

Goûtzy organic seed
Wholesaler and retailer of garden seed certified organic and guaranteed gmo free : Edible flowers, vegetables, flowers and herbs. Only available in Canada.
http://www.goutzy.com

Greta's Organic Gardens
Organically grown seeds, open-pollinated, heritage, vegetable, flowers, and herbs.
http://www.seeds-organic.com

Herb Gully
Producers and supplier of certified organic herb seeds and plants.
http://www.herbgully.com

Highmowing Organic Seeds
Offers seeds for vegetables, flowers, and cover crops, organically produced in Vermont.
http://www.highmowingseeds.com/

Horizon Herbs
Organically grown medicinal herb seed of echinacea, goldenseal and 400 other species of plants.
http://www.horizonherbs.com/

Natural Gardening Company
They sell certified organic seeds and plants, including heirloom tomatoes.
http://www.naturalgardening.com

Ready to Grow
UK site providing a range of unusual organically grown chilli (chile) seeds, and some non-organic exotic ornamentals including banana seeds and palm seeds.
http://www.readytogrow.co.uk

Salt Spring Seeds
Promoting self-empowerment by providing untreated heirloom and heritage seeds to grow high-protein, good yielding, and great tasting crops.
http://www.saltspringseeds.com/

Seeds of Change
Offers certified organic seeds and food, plus tools, books, and gifts available through online catalog.
http://www.seedsofchange.com

Southern Exposure Seed Exchange
Seed-saving organization offers many varieties of heirloom and other open-pollinated vegetables that grow well in the southeastern U.S.
http://www.southernexposure.com/

Sow Organic Seed Co.
Online catalog offering open pollinated seeds. Certified Organic.
http://www.organicseed.com/

Stellar Seeds
British Columbia grower of organic flower, herb and vegetable seeds
http://www.stellarseeds.com/

Terra Edibles
Since 1992. Open-pollinated, heirloom seeds, organically produced. Offers tomato, vegetable, herb, flower, and sweet pea seeds.
http://www.terraedibles.ca

Tomato Fest
Northern California seller of over 400 varieties of organic heirloom and open-pollinated tomato seeds. Also offers tomato related books, supplies, and gift items.
http://www.tomatofest.com

Tomatsidan
Organically grown tomato seeds from Sweden. There is an English list on the site, but most is in Swedish.
http://www.tomatsidan.se

Two Wings Farm
Small Canadian family farm offers Certified Organic gourmet and heirloom seed. Specializing in tomatoes and salad greens suited to the shorter season.
http://twowingsfarm.com

Wild Garden Seed
Sellers of Certified Organic heirloom and other open-pollinated seed varieties adapted for the Pacific Northwest.
http://www.wildgardenseed.com/

Windmill Point Organic Farm
Organic fruits and vegetables, organic seed catalog and heirloom tomato seeds available from Windmill Point Farm near Montreal, Canada
http://www.windmillpointfarm.ca/