When will it be ok to plant flowers here in maine outside?

Pansies should do fine for now. I live in CT, and started planting a few weeks ago-then we had a bout of frost. My flowers held up fine (pansies, larkspur, mums, rinoculus, snapdragons, and phlox). For now, you can plant, just stick with the hardier plants. I know it's probably a bit on the cool side up there. When frost season ends (I would think within the next few weeks) you should be good to go!

FlowersBirthday FlowersSympathy Flowersthe end of Mayskin disease