Name: Christie Central Ohio 43016 (Zone 6a) Plays on the water.
You can plant them now -- I just planted 3 in March and they are doing great - I live in zone 6a. Would be better to plant them now, than later when it is very hot outside.
The only time I hesitate planting anything is when it's very hot and dry, mid summer and the plant may have trouble adjusting or dry out too quickly. Otherwise, in it goes! Now is a great time for planting!!