You can plant them a few weeks before the last frost date. That way, by the time the leaves appear above ground, the danger of frost it passed.
Also, you could pot them up inside and let them get a head start, then plant them out after your last frost date
In the fall, I wait for the frost to nip back the tops, then I dig them out, cut off all the top growth, and store the roots in peat in a brown paper bag someplace cool and dark, but with no danger of freezing. An unheated basement, or attached garage do nicely.
Cannes can not freeze or they rot! So you must wait til it is no longer going to freeze the ground of course should be tillable, not frozen, same reason!
So early spring, is good, In NJ, probably April, you can google Cannes and find more information!
They will pop up this year and they grow very quickly!
Also you must remove them from the ground before it freezes the ground, so even after a first frost you may dig em up, but is better not to take that chance. Store them, the bulbs, in a basement, til next spring, they multiply quickly, so you will need to have increasingly more space for them or give some away to friends and family! Great gift for green thumb people!