Plant them now, it will give them time to throw some roots out before they sprout.
They are a herbaceous hardy perennial, so no problem about it being too early, they
wont start getting away until the soil is warm enough.
as has been said, raised beds, with good free draining soil is a must for good crops, and they take
years to settle in and throw a good crop, so dont move them about, choose the right place first time.
Hense its not really a good idea to plant them in pots, and put out later.