If you have hydrangea bushes loaded with big, gorgeous blooms, it's a pleasure to bring a few of the colorful blooms indoors to enjoy in a cut flower arrangement. Unfortunately, using hydrangeas blooms in cut flower arrangements often results in disappointment, as the blooms can sometimes wilt and fade soon after they're placed in the vase. A few simple techniques can keep the hydrangea blooms fresh for several days.
Use pruners or a sharp knife to cut hydrangea blooms early in the morning when the air is cool and the blooms are still hydrated. If you're cutting hydrangea blooms in June or July, you can cut the blooms with long stems, because the shrub won't yet be setting buds for the coming year. If you're cutting hydrangea blooms in August, leave short stems, cutting above the first pair of large leaves, so you don't accidentally remove next year's buds.
Put the hydrangea blooms into a bucket of cool water immediately, and bring the cut hydrangeas indoors. Heat an inch-deep amount of water in a saucepan until it's almost at the boiling point. Allow the water to cool for two minutes, then put the hydrangea stems in the hot water. Hold the stems upright for 30 seconds. The heat will seal the end of the stem so the sap doesn't escape.
Place the hydrangea blooms in a vase filled with cool water. Be sure the vase has been scrubbed ahead of time with a mixture of one part household bleach to nine parts water.
Cut an inch from the bottom of the stems when the hydrangea blooms begin to fade. Re-seal the bottom of the stems in hot water. Fill the vase with fresh water, and put the hydrangea blooms back in the vase.