Q.When Is the Best Time to Plant Lilac Bushes
I bought lilac bushes (starter plants). I’m not sure when to plant them. I live in Harrisburg, PA. I know we haven’t had our last snow or last hard frost yet. I don’t want to plant them and then have them die on me. And also butterfly bushes, I am in the process of looking for them too!

Certified GKH Gardening Expert
While in your zone, I would recommend spring planting, you may want to wait another couple weeks just in case another round of winter weather rolls in (unless you properly safeguard them). Here is an article that you may find helpful: https://www.gardeningknowhow.com/ornamental/shrubs/lilac/lilac-care-growing-and-planting-lilac-bush-plants.htm