Green hydrangea flowers result from harvesting before the full development of blossoms — just before the green becomes white, pink or blue. The massive flower heads and strong stems make hydrangeas easy to make into an impressive bouquet by themselves. Adding the slender stems of calla lilies of any color brings sculptural and textural interest into the composition. If possible, harvest the flower material in early morning when the stems and petals are fresh and rigid with water molecules. Promptly arrange the stems with stem ends in room-temperature fresh water. Keep the bouquet out of drafts and direct sunlight for longevity.
Fill a vase or other waterproof container one-half full with fresh water. Hydrangea flowers and calla lilies are rather bulky and heavy so a vase that is wide and low with a wide neck opening is better than a vase with a narrow, small neck and base.
Insert calla lilies into the mass of green hydrangea flower heads. Gauge the length of the calla lily stem before slicing it at an angle with a sharp knife. Avoid crushing the stem as you cut it. The calla lily’s trumpet-like bloom should rest at the same height or slightly higher than the surrounding stems and petals of the green hydrangeas. Calla flowers and stems bruise easily, so try to limit touching the flower as much as possible.
Slide the cut calla lily stems through the matrix of hydrangea heads into the water at the base of the vase. Space additional calla lilies evenly across the entire bouquet of hydrangeas.
Alternatively, rather than a mass of green hydrangeas with a polka-dot effect of singular calla lily stems throughout, group the calla lilies in bunches of three or five and insert them into the bouquet. This creates a bolder, heavier visual effect.
When done, double-check to make sure all stem bottoms of cut flowers reach into the fresh water to stay hydrated.
Pour out and change the water daily. This removes stale or bad-smelling water and helps keep the flowers fresh for a longer time. Pacific Callas website recommends adding a tablespoon of lemon-lime soda into the water to keep bacteria at bay.
Always make sure the vase is stable enough to support the flower weight and stem distribution. Change containers if necessary.