It is too early to plant asparagus. You will have to store them. They are usually planted 3-4 weeks prior to the average last frost date which is usually around Mothers Day. Planting will be around April.
Once you have the plants, keep the roots moist (but not soaking wet) by misting occasionally, and do not allow them to freeze or dry out. If it is necessary to keep the crowns for more than a few days, store them in a cool place or heel them in a trench of moist soil in a shaded location. Pack soil firmly against roots to eliminate air pockets. Take a look at our website on growing asparagus. http://extension.umd.edu/hgic/topics/asparagus