Most of the seeds or starts I buy are organic and heirloom. While nowhere near a complete directory, these are some of the best heirloom and organic seed sources. I’ve concentrated mainly on vegetable seeds, but many of the seeds companies offer a wonderful and dizzying array of flower seeds. Hopefully some of these links will help you in your quest for diversity. – Joanne
The NS/S Seedbank houses (for future generations) the seeds of crops and wild plants traditionally used as food, fiber and dyes by prehistoric and more recent cultures inhabiting the arid southwestern U.S. and northwestern Mexico. More than 2,000 different seeds are offered, representing traditional crops grown by Apache, Chemehuevi, Cocopah, Gila River Pima, Guarijio, Havasupai, Hopi, Maricopa, Mayo, Mojave, Mountain Pima, Navajo, Paiute, Puebloan, Tarahumara, Tohono O'odham and Yaqui farmers.
More than a half of the offerings are corn, bean, and squash (aka the three sisters). They also have some seed assortments and they offer products other than seeds (on their website), such as dried beans, posole, salsas, chiles, etc. They have some interesting links to other sites, as well. I’m excited that they are offering devil’s claw seeds, of which the dried plant pods are spectacular.
Turtle Tree Biodynamic Seeds
The first Demeter-certified biodynamic seed source I've found. Most of their seeds are also organic. They have some interesting and unusual Heirloom varieties for 2009 like: Feuer Kugel Beet, Dottenfelder Cabbage, Rose Potpourri Corn, Ping Tung Long Eggplant, Lanro Kohlrabi, Clemson Spineless Okra, Young's Beauty Pumpkin, Fireworks Tomato, Horehound, Perodovik Oil Seed Sunflower and Phacelia tanacetifolia(Bee Plant) . Seeds are offered in quantities from small (200 seeds) to up to 1oz. Turtle Tree offers seeds for Farm, Grain and Cover Crops as well as flowers and herbs.
Territorial Seed Company
I'm a fan of theirs. They offer a wide range of organic (and non-organic) seeds and gardening supplies as well as live plants. 2009 brings 225 new introductions they are continuing to offer a very small selection of biodynamic seeds including: Rodelika Carrots, Miner’s Lettuce, Erste Ernte Spinach, and Nantese Carrot. Our local organic nursery carries their seeds. I like that they tell you who bred the seeds. 2009 Vegetable Introductions include: Marte Asparagus , Flat of Egypt Beet, Soleil Bean, Goosebumps Pumpkin, Amethyst Radish, Bordeaux Spinach, Applegate Tomato, Gremlins Gourd, Lambkin Melon and Talon Onion.
High Mowing Seeds (100% Organic)
I think that their selection is interesting and I love that their seeds are organic. They offer 350 varieties of organic seeds and have favorites of mine like Cinnamon Basil. 2008 Introductions include: Bilko Cabbage, Crimson Sprinter tomato, Red Wing onion, Waldmann’s Lettuce, Zefa Fino and Katahdin Potato. Also check out there interesting specialty greens like Golden Purslane, Catalogna Emerald Endive and Astro Arugula. They also offer cover crop seed. (Thanks, Farmgirl Fare.)
Kitazawa Seed Company
They offer a tremendous selection of Asian Vegetable seeds and are the oldest seed company in America. If you are looking for something new for your garden this is the site to visit. Their selections of radish and beans alone are worth a look. 2008 offerings include Chef Specialty Gardens seed combinations, and Akatade. Don’t miss some of their more unusual offerings like Poha Berry. They are based in Oakland, CA and have been in the seed business almost 90 years. They have more than 250 varieties of traditional and heirloom seeds of Japan.
John Scheepers' Kitchen Garden Seeds
New additions for 2008 include: Redventure Celery, Marzatica Broccoli Raab, Beira Tronchuda Cabbage, Saltwort Okahijiki, Torino Italian Misticanza, Pasilla Bajio Hot Chile Pepper, Orange Chiffon Swiss Chard, Bordeaux Red-Stemmed Spinach, Galeux d’Eysines Squash, Jaune Gros de Paris Pumpkin, Helios Yellow Radishes, and Pony Red Watermelon.
Botanical Interests Seeds
I have probably bought more of their seeds than any other, as they seem to be well distributed. They offer a smaller but interesting organic line of seeds (the ones I usually choose). 2008 Organic Vegetable offerings include: Melon Old Orginal, Corn Sweet Painted Mountain, Pepper Chile Pepperoncini Greek, Tomato Pole Speckled Roman, and Mediterranean and Wild Arugla. They also offer a selection of gourd seeds suitable for birdhouses and carving, as well as Loofah seeds. Also don’t miss their selection of Heirloom and Organic flowers which includes, Amish Broomcorn, Sweet Annie and Sweet Pea Moroccan Spice.
Amishland Heirloom Seeds
Amishland have heirloom, heritage, exotic and foreign organically raised seeds, including many heirloom vegetable seeds. 2008 offerings include some rare tomato seeds, some of for which they are the only US source: Voyage Tomato (super rare), Riesentomate Aus Siebenburgen Tomato (exclusive), Eva's Schoeneck (Beautiful Corner) Pink Tomato (exclusive), Yellow Trifele Tomato (exclusive), and Fantome Du Laos~"Ghost Of Laos" Tomato (extremely rare and only source).
Victory Seed Company Open-pollinated and heirloom seeds. 2008 introductions include: Black Nightfall Bean, Acme De Giorgi Bros Tomato, Livingston’s Ideal tomato, Super Sioux Tomato, Lenticchie Verdi Lentils, Red Russian Tobacco, Cosmic Purple Carrots, and Arikara Watermelon. They also offer flower and herb seeds. Most of the seeds they carry are organic but are not necessarily certified. They are based in Oregon. Their Victory Horticultural Library is also an interesting resource.
Roguelands Seeds/Anioleka Seed Company
UK-based with an Oregon branch. Roguelands has an interesting selection of heirloom (and non) seeds including Cucuzzi, Salisfy and Israeli Melon. 2008 vegetable seed offerings include: Rocky Ford Honeydew Melon, Westerfield Cucumber, Maule’s Golden Jubilee Tomato, Armenian Yard Long Cucumber, Ananas Melon, Caribbean Red Chile and Greek White Beefsteak Tomato.
Sustainable Mountain Agricultural Center
They save heirloom beans (over 300 varieties). 2008 update: 29 varieties of heirloom bean seeds for sale and 5 heirloom tomato varieties. Offerings include: Big John Bean, Nickell Bean, Barnes Mountain Cornfield Bean, Tobacco Worm Bean, North Carolina Speckled Long Greasy Cut-Short, Vinson Watts Tomato, Margaret Best Yellow Tommy Toe Tomato and John Allen Yellow German.
Marianna's Heirloom Seeds
Based in TN, Marianna’s offers a great selection of heirloom tomato seeds with Italian culinary tomatoes a specialty. They also offer tomato starts and seeds for peppers and eggplants. 2008 introductions include Winsall Tomato, Chianti Rose Tomato, Tess's Land Race Currant Tomato, Rento Paste Tomato, Japanese Trifele Yellow Tomato, Big Zebra Tomato, Becker's Blaue Dolgener Tomato , Grandma Oliver’s Chocolate Tomato, Efiop Tomato, Turk Nuts Tomato, and Tomesol White Tomato. 2008 Pepper Introductions Include: Dulce Rojo Paprika Pepper, Purple Marconi Pepper and Grenidad Seasoning Pepper.
Le Jardin du Gourmet - Artistic Gardens
I love the sampler packs that this company offers and I've had great results with them. They often carry some unusual varieties and I've
ordered from them off and on for years and years. They seem reliable. When I first found them, they only offered seeds. Now they are a garden and flower shop as well. 2008 Seed Offerings include: Garden Huckleberry, Jaune Gros du Poitou, Aiguille Verte, Salsify Geant de Russie and Triomphe de Farcy.
The Cook's Garden
The Cook's Garden, in PA, have a great selection of vegetable, flowers and herb seeds and offer a small selection of Certified Organic Seeds. Introductions for 2008 include: Crystal Lettuce, Rainbow Cauliflower Mix, Yugoslavian Red Lettuce, Red Leprechaun Lettuce, Verte de Cambrai Corn Salad, Herkules Dill and Red Marble Cippolini Onion. Interesting organic oeeds include: Endive Grado Panclieri (direct from Italy) and Selvatica Arugula.
Superseeds / Pine Tree
A source for interesting seeds. This year they have added a selection of vegetable seeds suitable for container growing. They have a wide selection of seeds available (14 types of basil including cinnamon) and offer some unusual varieties of vegetables and herbs. Spring plant offerings include: Red Pearl Ligonberry, Sambuscus Canadensis, Pink Lily of the Valley, Kiwigold Raspberry and a number of varieties of sweet potatoes.
Irish Eyes – Garden City Seeds
A Washington-based seed company that has a good basic selection with some unusual varieties and many organic offerings. The online catalog lists asparagus roots, seed potatoes and seed collections. 2008 new introductions include Sasha’s Pride Heirloom Tomato, Silvery Fir Tree Tomato (Organic), Alaska Fancy Tomato (Organic), and Lime Green Salad Tomato (Organic).
Johnny's Selected Seeds
Deep selection of seeds. Some offered in large quantities. Some unusual and new varieties of flower, herb and vegetable seeds. Maine-based. 2008 organic introductions include: Pandora Leek, Persian Cress, Flashy Trout Back Lettuce, Yaya Carrot and Indigo Cabbage.
Penya Seeds A large selection of unusual and exotic seeds, including a good number of heirloom tomato seeds. They also sell seeds for fruit plants and trees as well as other trees and landscape plants. 2008 offerings include: Brazilian Oval Orange Eggplant, Precoce D'Argenteuil Italian Asparagus, Grappoli Corbarino Tomato, Hegari Heirloom Sorghum, German Heirloom Melon, Pepino Tree and Cuor Di Bue Tomato (Heirloom).
Harvest Moon Farms & Seed
Based in Indiana, they offer a lovely selection of Heirloom and Rare Seed Selections. 2008 introductions include: Michelet Rames Fageolet Bean, Sarriete Winter Savory, Wallone Frisee Endive, Madrilene Lettuce, Val d'Orges Lettuce, Prover Wild Cabbage Greens, Juane du Doubs Carrot, Muscade Carrot, Parisienne Market Carrot, Ciboule Rouge French Scallions, Blanc de Vaugirard Onion, Blanc de Pompei Cippolini Onion, Juane de Vauriac Beet, and Crapaudine Black Beet. They also offer bulk seeds for culinary professionals.
Abundant Life Seed Company
Based in Oregon, they offer 100% organic seeds. In business since 1975, their goal is to offer true-to-type open pollinated varieties grown using only certified organic or biodynamic farming methods. They are a sister company to Territorial Seed. 2008 introductions include: Champion Collard Greens, Brocade Bi-Color Corn, Cracoviense Heirloom Lettuce, Tennessee Cheese (Spanish Heirloom) Pepper, White Currant Cherry Tomato, Orangetti Winter Squash, Waltham Butternut Squash, and Cesar Celeriac.
Wood Prairie Farm
An Organic Family Farm in Maine. They specialize in heirloom and gourmet organic seed potatoes (including fingerling seed potatoes) but also offer some organic vegetable seeds. In 2008 they also offer cheese from Neighborly Farms, Baking Mixes, Grains and Flours, Dried Fruits, Nuts & Beans and Fresh Seasonal Organic Vegetables: like Chantenay carrots & Red Ace beets.
Nichols Garden Nursery
An Oregon based herb and rare seed company, they have some interesting heirloom and rare seeds. Some of their seeds are organic. 2008 Offerings include: Stonehead Cabbage, Envy Carrot, Costmary, Trenague Chamomile, Hori Hori, Golden Sweet Melon and Elephant Head Amaranth (Organic). They also offer seeds for Crane Cantaloupe*, Jimmy Nardello's Sweet Frying Pepper* - Organic, and Inchelium Red Garlic Organic* - these three are included in theSlow Food Ark of Taste, but that is not necessarily noted in the seed listing.
Peaceful Valley Farm Supply
They offer a nice selection of organic seeds from Peaceful Valley Farm Supply (their own label), Seeds of Change Organic Seeds, Horizon Medicinal Herb Seeds, Turtle Tree Biodynamic Seeds and Tomato Fest. They also offer many organic gardening supplies as well as Certified Organic Vegetable & Herb Starts, Bulk organic seeds and bareroot stock.
Seeds of Change
They sell organic seeds, including many heirloom varieties. They are probably the most visible organic seed company in nurseries and grocery stores. 2008 introductions include: Uchiki Kuri Winter Squash, Tavera Bean, Hopi Blue Flour Corn, Tadorna Leek, Touchstone Gold Beet, Integrata de Wild Lettuce, Brightest Brillant Quinoa, Numix Sandia Pepper, Riccia Pancaleri Endive and Leonardo Raddichio. They are also offering in 2008, some interesting heirloom apple trees (live plants) and well as some seedling collections.
My experience ordering from them a few years ago was not positive. The tomato plants we received looked half dead when we got them but they did survive. I’ve also had poor customer service from them regarding back orders. I like buying organic seeds - so I continue to support them but I do take my poor service experience into account and I wouldn’t order plants from them again – or supplies. Please note that they are now owned by the Mars Inc. (the candy company).
The Heirloom Garden
Their Farm Annual features several hundred varieties of heirloom annuals, perennials, biennials, herbs, vegetables and roses. They are located in Maine. The seeds they offer come from the Seed Saver's Exchange. They have a nice selection of starts. As of January, 2008 there is no seed listing for this year.
Wondering if old seeds are viable?
Read my article here.
Seed Savers Exchange Founded in 1975, Seed Savers Exchange is a nonprofit organization that saves and shares heirloom seeds. New varieties for 2009: Arikara Yellow Bean, Pencil Pod Gldn Wax, Bean, Smoke Signals OG Corn, Giant Exibition Coleus, Petite Gris OG Melon, McMahon's Bird OG Pepper, Brandywine OG Tomato, Chalk's Early Jewel OG Tomato, Eva Purple Ball Tomato, Hartman's Yellow Gooseberry OG Tomato, Redfield Beauty OG Tomato, Sheboygan OG Tomato, Trucker's Favorite Pink OG Tomato. OG= Certified Organic.. They are perhaps the first place to look for unusual Heirlooms. They also offer tomato and pepper plants, seed potatoes as well as lovely selection of flower and herb seeds. They also offer a program by which qualified groups may receive subsidized or free seeds for garden projects.
Baker Creek Heirloom Seeds
A great selection of Heirloom seeds - more than 1275 varieties in 2009 and some unusual ones. Their 2009 catalog is 124 pages, full color, and has gorgeous photos of many heirlooms. They offer a dizzying number of varieties, including Jake’s Snake Melon, Burgundy Okra, St. Pierre Tomatoes and even Spencer Sweet Peas. For 2008, I noticed a number of seed offerings which are Thai Seeds (or seeds likely indigenous to Thailand?) For 2009 I noted a number of French Heirlooms. Some of these 2009 offerings include Kamo Kamo Pumpkin, Shishigatani or Toonas Makino Pumpkin, Chaco Canyon Bean, Beurre De Rocquencourt Bean, True Gold Sweet Corn, Dragon's Egg Cucumber, Sweet Siberian Melon, Jaune D'or Ovale Radish , Dr. Walter Tomato, White Belgian or Blanche A Collet Vert Carrot, Poona Kheera and Sikkim Cucumbers and White Currants. They also have a Poultry Farm and will be offering chicks in the spring and summer - rare breeds.
Founded by Gary Ibsen, they offer more than 600 varieties of certified organic heirloom tomato seeds. They are also the organizers of the renowned Carmel TomatoFest in September. The 2008 seed catalog list more than 100 new offerings including: Taxi (one of our favorites), Thai Pink Egg, Elmer’s Old German, Beam’s Yellow Pear, Black Sea Man, Henderson’s Winsall, Halfmoon China, Green Sausage and Ispolin. This is a really great place to start looking for Heirloom tomato varieties. In-season (late June to early Nov) they also offer Heirloom tomatoes which they will ship to you in 10 pound boxes.
A service that helps farmer's and small growers market their produce. The seed page covers flowers, fruit, vegetables, tubers, herbs, trees, bulbs and grains. There are some unusual offerings and many are organic or at least non-GMO (but carefully read the notes as all are not organic). In need of Nankeen Cotton Seed (Heirloom Brown), Coffee Seeds, Sorghum seeds, Red Noodle Asparagus Bean seeds, or fablonelystynj tomato seeds? This is the site.
All seeds are locally grown, 100% organic and open pollinated in the Pacific Northwest. They don't have a huge selection but many heirloom and unusual varities are in their catalog. They offer a few Slow Food Ark of Taste/RAFT seeds like: Hutterite Bush Dry Bean, Lina Cisco's Bird Egg Dry Beans, Speckled Butterhead Lettuce and Red Fig Tomato.
Other offerings which caught my eye in 2008 are: Flashy Trout's Back Lettuce, Magentaspreen, Ceylon Tomato, and Golden Sweet Snow Peas (with purple/pink flowers!). They don't have a website but you can email them and they will send you a catalog.
JL Hudson Seedsman
This La Honda, CA company is a "public access seed bank." They have a large selection of seeds. Non-vegetables are listed under latin names. 2008 Specialty vegetable offerings included Amaranth Chinese Giant Orange, Basil, Ocimum sanctum (Holy Basil), Beet, Sugar Beet, Chicory Variegata De Castelfranco, Popcorn Miniature Blue, Watermelon Blacktail Mountain, Mangel Wurzel Mammoth Long Red (Beet), Melon Vert Grimpant and Huazontle (Chenopodium). Most seeds have a germination percentage and last tested date. They also offer organic seeds.
Swallowtail Garden Seeds Swallowtail Garden Seeds is a local seed source for us (in Santa Rosa, CA). They offer "untreated" seeds for Vegetables and Flowers and many Heirloom Varieties in the more than 1,200 varieties of seeds offered. 2008 offerings include: Andrew Rahart's Jumbo Red Tomato, Emerald Evergreen Tomato, Purple Calabash Tomato, Watermelon Beefsteak Tomato, San Juan Ananas Melon, Purple Haze Carrot, Yellow Wonder Alpine Strawberry, Fresca Strawberry and Berenice Green Lettuce.
Renee's Garden Seeds
Based in Carmel, CA, Renee's Garden Seeds offers a great selection of cottage garden flowers and gourmet vegetable and herb seeds from sustainable sources. There are only a few organic labeled offerings. They have a lovely selection of sweet pea seeds, some of which are heirloom. I've had good results with their container sweet pea, "Heirloom Cupid". Don’t miss the new seed collection for 2008: “Native American
Three Sisters Garden:” Earth Tones Dent Corn, Scarlet Runner Beans to twine up the corn stalks and Sugar Pie Pumpkins to cover the ground. Renee also offers some valuable articles on growing and gardening, including ones on container gardening, starting sweet peas or tomatoes indoors and gardening with children.
The US Distributor for Franchi Sementi is in Winchester, MA and they offer a wide and interesting selection of Italian vegetable and herb seeds including beans wild arugula, gherkins, Agretti/Roscano/ Barba di Frate and marina of chioggia pumpkin. They also have a small selection of organic seeds. 2008 introductions include: Panca povoa verde Cabbage, Galea de Folhas lisas Kale, Janosik Watermelon, Wallone Endive, Zucca da Marmellata Jam Pumpkin, and Lungo rosso sardo a punta bianca Radish.
Franchi Sementi Italian Seeds - The UK-based company. In addition to the US offerings they have legumes seeds (faro, lentils borlotto), capers, black cabbage etc. and a chef’s line of seeds. They also offer mushrooms and truffles but I doubt they will ship those to the US.
Thompson & Morgan
The venerable British Seed company will ship some seeds worldwide and now offers an organic vegetable line of seeds. They have 56 varieties of (non-organic) Sweet Pea seeds and some unusual varieties of vegetables. Their website also offers a selection of seeds good for children (albeit non-organic).
One Garden Seeds
Offers Certified Organic & Biodynamic Chinese medicinal seeds grown in North America and Certified Organic and Biodynamic North American Indigenous Seeds. One Garden in Missouri is affiliated with the Ozark Botanical Garden and is dedicated to research and conservation of medicinal plants from temperate zones worldwide. They have a collection of more than 500 medicinal plants. One Garden offers seeds in bulk as well as in smaller quantities. Be sure to take a look at their: Deep Diversity Seed Collection.
Garden Medicinals and Culinaries
Virginia based, they offer
210 varieties of herb, vegetable and flower seeds and plants - mostly herb seeds. Most organically grown, all open- pollinated, and non-GMO. Offer false unicorn seeds and seedlings, salad burnet, red leaf plantain, and agrimony. Some Heirloom tomato and vegetable seeds, like Belyj Naliv' and Wickline cherry.
An interesting selection of seeds for Herb, Flower and Vegetable plants. Horizon Herbs specialize in medicinal herbs and plants. A number of their seeds are organic. They offer a Tasty Tea Collection, Organic (7 seed packets): Chamomile, German; Fennel; Hibiscus; Jiao-gu-lan, Japanese; Navajo Tea, SW; Spearmint; Tulsi-Rama. Other non-seed offerings include roots and tubers like Turmeric root and Chinese Wild Yam. Some unusual seed offerings that caught my eye was Red Trillium, Chinese Tea (Camellia sinensis), Yellow Maca and Wooden Turtle. 2008 offerings: Arhat Fruit, .Shatavari Asparagus, Ayahuasca (Yage) (Banisteriopsis caapi), Balm of Gilead, and Sheng-ma (Cimicifuga dahurica).
Salt Spring Seeds
A source for Canada-only Organic Seeds - many heirloom and heritage varieties (they do not ship to the US).
The Plimoth Plantation Museum Seeds
Kitchen, Heirloom and Native seeds traditional to a 17th Century garden. From betony to woad, alexanders to dipper gourd. A limited selection but an interesting one.
Unusual Plant Resources
Their catalog alone is worth the order - it doesn't have any pictures but lists thousands of tree, bushes and plants that they have available. They often have some varieties difficult or impossible to find elsewhere. The plants I received were healthy and all transplanted well. I've bought trees, bushes and perennials from them.
Digging Dog Nursery I've had mixed results erring on the good side. They have many species of California plants and often many varieties that are hard to find. They are a small family-run company in Albion, CA (Mendocino) so you can actually call and talk to someone who knows something. Jack likes euphorbia and they offer more than 20 varieties. They tend to specialize not offering tons of species but a number of varieties for each. If you are looking for the unusual variety of a california plant they are worth a look! I love their epimedium choices. They have many woodland choices as well (part-shade) which is great for us! (P.S. We had a nice visit to their nursery in Spring 2008.)
Trees of Antiquity
A wonderful source for Heirloom apple and stone fruit trees (they sell Apples, Apricots, Berries, Blueberries, Cherries, Crabapples, Figs, Grapes, Jujube, Kiwis, Mulberries, Nectarines, Nuts, Olives, Pawpaws, Peaches, Pears, Persimmons, Plumcots, Plums, Pomegranates, Quinces, Strawberries). Trees are shipped bareroot. This is the new incarnation of the Sonoma Antique Apple Nursery. Most of the rootstock is organic.
Cross Country Nurseries
While not organic, Cross Country Nurseries, in NJ, offers a huge selection of chile and sweet pepper plants as well as tomatoes. If you need unusual chiles you will likely find them here. New for 2008: They are offering eggplant. Be sure to look at their handy comparison charts for tomatoes, chiles, and eggplants. Other Resources
The Organic Seed Alliance Based in Port Townsend, WA, they are a non-profit organization who "...supports the ethical development and stewardship of the genetic resources of agricultural seed". They offer a huge database of seed producers on their website (free reg. req.). They also hold workshops in the Pacific Northwest and host a biannual Seed Grower's Conference.
The Seed Search (5th Ed) by Karen Platt This U.K. book lists "sources for 40,000 flowering seeds including all types of flowering plants and more than 9,500 vegetables. Includes open-pollinated, untreated, heirloom and organic seed, many rare species." And contact information for 500 world-wide suppliers are included.
Brogdale Horticultural Trust - Includes a great online database (UK) of heirloom fruit tree varieties in their collection. Their National Fruit Collection: "This ‘living’ Collection of temperate fruit varieties is of international renown and is seen as one of the treasures of England for its scientific, horticultural and historic importance." For example, they list over 1800 varieties of apple trees (many with photos of the fruit). Types of Apples, Apricots, Currants, Cherries, Cider Apples, Cobnust, Gooseberries, Crab Apples, Pears, Plums, Quince, Vines, etc. are listed. If you live in the UK you can also buy bare root from them and they also do custom grafting for a fee.
An interesting site basically a database of gardening and garden-related mail order companies (including seed companies), rated by the members of Dave's Garden. Includes lots of comments.
William Rubel's List of Seed Companies
This is a well-conceived and -annotated list with reviews of 40 seed companies with websites. A few of the links need updated but it's still a great list.
A website directory of Eco-Friendly and Holistic health products offers a massive list of seed sources organized by state.
Eastern Native Seed Conservancy
Home of the CRESS Heirloom Seed Conservation Project, and the Native Seeds Project. Their mission is to preserve rare genetic stock and offers to the public a sampling. In some cases they are the only catalog offering some of these seeds, and in some cases one of the only places preserving these seeds - some are rare, very rare or even endangered seeds. Really unusual selection of native beans, corn, squash and sunflowers as well as really interesting melons and tomatoes. If you are looking for really unusual varieties to grow start here - plus you‘ll be supporting the conservation of the varieties. Based in Great Barrington, Mass. Update: They no longer sell seeds.
Seeds of Diversity - Canada's Heritage Seed Program The members collect and share over 1900 varieties of fruits and vegetables. Check out their Heritage Plants Database - which lists flower, fruit and vegetable seeds available in Canada (with links to where they are sold). They also offers a good list of Canadian Seed sources.