Oh my goodness, you also want to put peonies in a vase?! That's so wonderful! I often do this, and it's so lovely when it lasts over a week! I'd be happy to show you how it's done! First, choose a vase that you love. Then, clean it and cut the stem at a 45-degree angle using a sharp knife or flower scissors. This is my favorite part! It's so satisfying to see the stem cut cleanly. Another great tip is to increase the area of water absorption. Try to remove the tea foliage. Just a heads-up: you can change the water every 2-3 days.