Can i plant Rudbeckia in NE Pennsylvania in August?
I would like to know if they'll survive winter and return next spring/summer?
Yes, you can plant Rudbeckia although it is preferable to wait for cooler weather. If you put it in now, provide the plant with afternoon shade, mulch and water every couple of days for a week then weekly when there is no rain. Next year, it will not need this coddling. Rudbeckia hirta is a short-lived plant, often behaving as a biennial so let it go to seed. Other Rudbeckia species behave as typical perennials. It is important for all plants to be well-watered going into winter to prevent winter kill.