The large blooms of peonies (Paeonia spp.), hardy in U.S. Department of Agriculture plant hardiness zones 3 through 8, add color and drama to your early summer flower arrangements. They can last as long as eight or nine days in water, if you take the proper precautions. Don't cut all or even most of your peony blooms -- removing more than one-third of the foliage from a peony plant can endanger its life.
Clean Your Tools
Before going into the garden to cut your peonies, clean all of the tools you need, including a pail large enough to hold the flowers, sharp pruning shears and a vase. Add a few drops of dish detergent and 1 teaspoon of bleach to each gallon of water you use for cleaning. When you're finished, rinse the items. Pat them dry with a clean dish towel and fill the pail with about 12 inches of lukewarm water. Carry the pail and pruning shears with you into the garden, either in the early morning after the dew has dried or in early evening before any dew has fallen.
Cut the Peony Flowers
To ensure long life and minimal insect or weather damage to the flowers, cut them while they are still in bud or just barely beginning to open. Buds at the proper stage for picking should be about 1 to 1 3/4 inches in diameter and have a slightly squishy feel when squeezed, much like a marshmallow. Cut each bud so that its stem is 14 to 18 inches long, and be careful to leave one to three pairs of leaves on the part of the stem that remains on the plant. After shaking or brushing off any ants clinging to the bud, snip off the lower one-third of leaves from the cut stem. Then plunge that stem into your pail, so that the water comes almost up to the neck of the flower.
Arrange the Peony Flowers
After you bring your flowers into the house, fill your clean vase one-third full with lukewarm water. Add cut-flower food to that water), using 2 teaspoons for each quart of water -- or whatever amount is specified on the container or packet. Reaching down into the pail of buds with your pruning shears, snip off the base of each stem underwater, making the cut at a slant. How much of that base you remove from each stem depends on how varied in height you need the buds to be. Remove all of the leaves except those that will be above the water level in the vase before you arrange the buds. You can condition those blooms by placing the bouquet in a cool, dark place for a couple of hours or overnight.
Preserve Peony Flowers
When you bring the bouquet out into the light again, place it in an area out of direct sunlight and away from heat sources. The peonies will last longest where the temperature remains between 65 and 72 degrees Fahrenheit, and some may take two or three days to open completely.
Every three days, pour the old water down the sink, and clean the vase and pruning shears as you did before. Refill the vase with fresh lukewarm water and cut-flower food. Recut the stems under water again with the pruning shears, snipping off about 1 inch from each one, and return the blooms to the vase. You also can store peony buds dry in your refrigerator for two to three weeks, as long as that refrigerator doesn't contain produce -- its ethylene has an adverse effect on cut flowers. After you bring the buds in from the garden, wrap them in newspaper and place them inside a zip-top, 2-gallon plastic bag. Zip the bag shut and lay it flat on one of the refrigerator's shelves.
When you are ready to use the buds, re-cut their stems and arrange them as you would fresher flowers, but in warm rather than lukewarm water. They probably will be wilted when you take them out of the refrigerator, but should revive in water.