The only way to keep the one you have now upright is to use a peony ring for support best put out in the spring when it shows above ground so the peony can grow up through it. Sealing the wrap helps to ensure minimal moisture loss from the flowers themselves. Hydrangeas may get so heavy that they start to bend and leave a giant space in the middle of your plant. At planting time add compost limestone or bone meal sand a light fertilizer and other amendments suited to your soil to give your new plants a boost. Provide potted barerooted or divided peonies with a fairly large hole making certain that their round pink buds or eyes are just barely covered by the soil.
Just make sure that the support you use is the right size for you peonies. Im not thrilled about the idea of putting in stakes for each plant if thats my only option. The best solution is a grow-through support which helps keep the top-heavy blooms upright. Our quest to find the perfect ensemble of pet safe shade friendly and easy to maintain plants because of the rave reviews Glovers has which I spent an hour reading through simply because they were pleasant to read. Hydrangeas may get so heavy that they start to bend and leave a giant space in the middle of your plant.