People come look at my farm then invariably ask what seed company I use. Like it's the seeds that make the difference? Well anyway, I don't use just one. In fact, I've used plenty. And I've acquired seeds from other sources too. My sources include:
Growing my own
Swaps with other gardeners
A local seed producer
Local seed exchanges
Mail order seed companies
I tend to avoid stores here. I have experienced terrible germination rates from some of the store purchased seed, so I suspect there is a problem on how the seed has been shipped, stored, or otherwise handled.
Recently I have been growing some of my own seeds. I can get high quality, fresh seed this way with high germination rates. I love it! It's true self reliancy.
I also swap or buy seed from other gardeners. I can get some varieties this way that are no longer available in the seed catalogs. Most of the time the seed is excellent. I've only had three cases of poor seed, so I longer deal with those individuals.
The University of Hawaii produces some seed for varieties that have been selected for Hawaii. I occasionally will buy some to give the varieties a try.
A few times a year there are seed exchange events around the island. I love these events because I can swap for plants that I can't find anywhere else. I've come home with sugar cane, taro, turmeric, sweet potatoes, and more.
Then there are the mail order seed suppliers. I order from a number of them for various reasons. And since I'm forever experimenting and exploring, I order from several of them each year. When I don't need much from a company, I will ask among my friends and neighbors to see if they intend to place an order too. That way we can share the shipping costs.
I'll go down the list and note why I order from them:
...Johnnys Selected Seed - good selection, fair shipping rate, fast service, reliable, accurate, good germination, great service
...Nichols - great people, good customer service, interesting selection, good seed, monthly specials
...Stokes- good bulk prices, good seed, commercial varieties available, good service
...Holmes - ditto
...Rupp - ditto
...Osborne - ditto
...Dixondale - good source of onion & leek seedlings
...Willhite - interesting watermelon and melon varieties
...Twilley - interesting commercial sweet corn. Expensive seed. I hardly ever order.
...Seed Savers Exchange - interesting varieties. And they support community gardens, a nice touch.
...Native Seed Search - very interesting native seed. I like them.
...Rancho Gordo - very interesting Mexican seed. I like them.
...Kitazawa - good oriental varieties
...Evergreen - good oriental varieties
...Territorial - sometimes carry things that I an looking for
...Pinetree - ditto
...Shumway - I've ordered OP corn from them. They are not as interesting since they got purchased and are now affiliated with Jung Seed. Last time I looked their shipping rates were outrageous. I don't order much here anymore.
...Baker Creek - love the catalog. Also has interesting varieties you can't find elsewhere.
...Purcell Mountain - good price on bulk bean seed. Interesting varieties. Fast service.
...Wood Prairie - good seed potatoes. Good service.
...Victory - good service. Nice people.
...Southern Exposure - I've found some interesting stuff here.
...Amishland - I only order if she has a rare variety I am looking for. Prices are outrageously high for a small amount of seed and sometimes the germination rates are abysmal. I've gotten zero germination on some seeds.
...Sandhill Preservation Farm - good source for sweet potatoes. They have some hard to find seeds.
...Tomato Bob - I only order during the off season because he can be real slow filling orders otherwise. But I like the guy. His prices aren't the cheapest, but he often has specials and carries varieties that can be hard to find.
There are some companies that I no longer order from because either their prices are quite high, their shipping rate unreasonable, or their seeds have poor germination rates. But make up your own mind.
Before ordering from an unknown company, I usually check out their reputation on davesgarden.com.