Although this 59 second Wonder-How-To video is entitled “How To Grow And Care For Black-Eyed Susans”, it really only tells you how to water the newly-planted established plants thoroughly. According to the Wonder-How-To spokesperson, “It’s really important to reduce transplant shock by soaking perennials very well.”
You use a hose, preferably with a long nozzle attachment, that is producing a gentle stream of steadily trickling water. You water them from the top first then move the hose down to the base and let the water really soakd the root area. Leave it there for an half an hour if you can. That’s really all there is to it…