Not all seeds or seed companies are created equal. Since 2010, we purchased seeds from all the major vendors (and some of the minor ones, too) and found that quality varies greatly. For instance, you might find that kale seeds from Company A yield better than the kale seeds from Company B but Company B's arugula is better than Company A's. Further, not every seed is good to grow microgreens and you will have to run a lot of experiments to see what works (and doesn't work) in your environment. Below is our summary of the top seed companies in America, with our recommendation of our favorite seeds.
1) Johnny's Selected Seeds - Winslow, ME $$$$
They maintain an onsite seed lab, and set and maintain minimum germination requirements that consistently exceed those of the US Federal Seed Act. Overall we found this company to be expensive, but superior when it comes to customer service and on time delivery. Johnny's easily has the biggest selection of microgreen seeds.
2) Todd's Seeds - Wixom, MI $
Todd's specializes in Heirloom, non-gmo, open pollinated vegetable, flower and sprouting seeds. All seeds are inspected and packaged the old-fashioned way -- by hand. We found that this company has the highest quality bulk seeds at the lowest wholesale prices in the industry.
3) High Mowing Seed Company - Wolcott, VT $$$
If you need 100% certified organic seeds, 100% of the time, then this company is the one! Bred to perform best in organic conditions, the seeds are bred with robust, vigorous genetics and modern disease resistances. We used this company on a commercial scale when we built a certified organic program that was selling to 42 Whole Foods Market stores. Very dependable and great customer service.
4) Kitazawa Seed Company - Oakland, CA $$
This company is the oldest seed company in America. Since 1917 they have been the source for oriental vegetable seeds for home gardeners, retailers, and commercial growers. They have great prices and excellent customer services.
5) Mountain Valley Seed Company - S. Salt Lake City, UT $$$
Since 1974 they have been providing fellow passionate growers with wide range of high quality seeds at wholesale prices. This company has a great selection of microgreen seeds.
6) Sprout People - San Francisco, CA $$
This company specializes in sprout seeds, but these seeds can be used to grow microgreens. Perfect for the home grower that can't afford to buy bulk. A great selection at reasonable prices, since 1993.