Answer: Since you were just given them, I assume you mean the rhizomes for the German bearded type of iris, rather than actual iris bulbs which require a different type of care. These plants are quite winter hardy but are subject to freeze/thaw damage until they become rooted and established. The rhizomes can be planted as soon as the heavy freezes stop -- the heavy freezes can cause the ground to freeze and thaw and possibly "heave" them right out onto the surface again. If they are of sufficient size and are planted into well prepared soil it is possible they will bloom for you this year, but it is more likely they will give you a good show next year.
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