Perennials for zone 5 will help you select ones for your garden. You have an incredible number of options! You just need to know how much sun the area gets during the summer. Then, think about what time of year you want flowers and what flower colors you like. You can pretty much plant anything in the fall as long as you check on it during the winter. Freeze and thaw cycles during the winter can cause smaller, newly planted perennials to heave out of the ground. If this happens, just put it back in the hole and add a little dirt and mulch on top. Also, water if the winter is dry. Our planting and care guide has additional tips.
Thanks for writing!