Caladiums in Minnesota...When to plant out?

I posted this in the "Bulbs" section, too-sorry for the repeat :)

Just curious-when should I plant my Caladiums outside in their containers? Usually I start them indoors on a heat mat under lights but got a late start this year. It's still been cool at night. The instructions that cam with my bulbs (from Bill) say after temps are >65 degrees, but I'm wndering if I can push that a little bit?
Thanks!
Deb

I haven't planted my callas yet. Just had cold night last week and want to wait until temps even out. If you can start them indoors and hold for enough time for temps to level out, you would be ahead of the game. Wouldn't chance outdoors yet, pricey bulbs...just my opinion.
Marcia

I should be getting my bulbs from Bill very soon... i was hoping to have them yesterday.... BUT - i know I'll probably be planting too early but I dont have a choice.... and with the weird weather we have been having.... 80's early in the week, now 60s and currently it's 39f

I recall i've done mine [zone4 S-central WI] mid June. I'm thinking they just wont start to grow until they are ready.... once the soil temps get warm enough.