Shallots are a more delicately flavored relative of the common garden onion. Most that are sold to home gardeners resemble oversized onion sets. While they are closely related to onions, they are actually part of a group of perennial onion relatives, called the Aggregatum group, that form clumps of perennial bulbs and were not, until recently propagated from seed.
Shallots are as simple to grow as onion sets: just push the small bulbs into the ground, root end down, until the tip is just below the surface. They should be planted on eight-inch centers, as each shallot planted will grow into a clump of up to a dozen bulbs. Harvest and storage are also the same as for onions, though most kinds of shallots store much better.
You could get your start in shallot growing simply by going to the market in early spring or fall, buying a pound or two of shallots, and planting them. But more unusual kinds can be ordered by mail or traded through a seed exchange. In recent years, seed-sown shallots have been developed by Dutch seed houses (sold here in the US by mail order) and they work very well, though you will get only the standard coppery bulbs from them, not the unique, vegetatively propagated heirlooms types.
Some of the interesting kinds of shallots we’ve tried over the years are Frog’s Leg, or Brittany shallots, French Red, French Gray, and Giant Red shallots (though some knowledgeable growers consider this last type to actually be a so-called “potato onion”). If you ask around, you might find a neighbor who has a special heirloom strain of his or her own that they’ve kept in the family. Maybe you’d like Odetta’s White, or Granma Featherston, or maybe one that I saw in the Seed Saver’s Exchange Yearbook called Sleeping Beauty—a good keeper, I hope!