Shallots are an ancient allium originally hailing from somewhere in central Asia, from there they came to India earning the nickname little onion. Onward from India the little onion was brought to the near east, then traded with the Roman's and Greek's. Through time and trade they came to western europe were most bulbs and seeds are produced today. Though that balance is shifting yet again as more producer's are becoming involved in North America, Canada and the United States in particular.
Today the vast majority of Shallot seeds are grown in North western Europe, The Netherlands in particular. In recent history the same was true for bulbs as well, now there are bulb producers from as south as St. Louis, Missouri to as far north as Calgary, Alberta. There are also a few small shallot seed producer's coming online, such as myself.
The care I would advise for Shallots is much the same as what I would provide for its other allium cousins, in particular Onions and Garlics. Im sure it seems obvious to some but I'll state it, Onions and Garlic require such similiar care to Shallots because they are all alliums cultivated primarily for their bulbs.
Unlike both Chives and Leeks I would recommend sowing Shallots in soil that has not had many amendments Ie. Compost, Manure and slow release fertilizers. Shallots are also similiar to Onions and Garlic in that the all transplant well when started from seed. I start my shallots in small cell tray on a sunny window sill in mid march typically. This is a a fantastic way for growers in colder climates to get a jump start on bulbing alliums, If your season doesnt have atleast 100 forst free days this is one of the only ways to get a harvest.
One last paragraph on advice for shallots. Sow them with a spacing almost identical to onions, though you can get away with slightly tights spacing planting this cultivar. They also store and cure almost identically to onions and garlic. The only difference i've found is their cold resistance. Planted next to a heat sink with sufficient thermal mass shallots can be fall sown in zones 2 and 3 for a early summer harvest the way people in warmer climates plant garlic. My heat sink of choice has been a concrete foundation.
Thats about it for the care and growing of these simple, easy to grow alliums. They're great to have in the pantry and store for about a season. Give them a try next season in a bed with onions or garlic to keep things nice and easy!