Artichokes are perennials that flower and fruit the second year. Elsewhere than Minnesota, that is.
In Minnesota, artichokes are considered an annual due to our below freezing temps. This presents a dilemma, to say the least, but not an insurmountable one. Urban Ton Project, a St. Paul, MN couple's experiment in urban gardening, found a way to trick an artichoke plant into producing flowers its first year.
The duo found by starting the chokes early (February in Minnesota,) the plants are able to grow to a good size by spring. Veggie Gardening Tips says late January is even better. Four to six weeks before planting, the artichoke plants are introduced to cold temperatures, a technique known as vernalization. This makes the plant thinks it's entering winter, so when the temperatures rise again, it will believe it's a new year and time to produce flowers. For best results, at night the temperatures should be below 50, but above freezing.
Here in Minnesota this can be accomplished by moving them outside to a cold frame in April. A cold frame is a four-sided frame of boards with a removable glass or plastic top. Many gardeners use bendable tubing in arches placed over the frame every four feet, and covered with single, or double layer plastic. The frame is placed on the ground and is used to house, protect, and harden off seedlings and small plants, without artificial heat. Just be sure to vent the plastic by lifting a corner during the day, or the chokes could "cook" from the buildup of heat. Re-cover at night.
You can also try planting in movable pots, brought indoors when the nighttime temperature is predicted to fall below freezing.
Veggie Gardening Tips suggests "three or four weeks of vernalization during March or April should be sufficient to fool the artichoke plant into believing that it has lived through a winter season and encourage the plant to bud and produce at least a small harvest of those delicious chokes that same year."
Granted, this is a lot of work for a mere 1-3 chokes per plant, with each plant taking up about 4-5 sq. ft. of space, but if you love artichokes, or simply admire the gorgeous purple flowers the choke turns into if left alone, it might be worth it.