As we all know, flowers are highly perishable. That’s part of what makes them so special. Usually our goal is to extend the life of the flowers for as long as possible after they are cut. Here’s some great tips on how to do so from Jeanne Rose which appeared in the Visalia Times-Delta:
Several years ago I took a few college-level classes in floral design, where we were taught the proper care of cut flowers from the time they were harvested until the final arrangements were made.
The first step in this care, after cutting, was to place the flowers into lukewarm water immediately after they were cut.
Since then, I have learned that Dr. Allan Armitage, a professor of horticulture at the University of Georgia, has conducted many years of extensive research on when to harvest flowers and how to extend their vase life for cut-flower growers. His research efforts suggest variances from a number of commonly used practices.
Commercial cut-flower growers usually harvest just as buds begin to show color, which reduces shipping space and causes less damage than would occur with open flowers. Home gardeners can also follow this practice for the longest vase life.
There are some exceptions, though. Spike flowers, such as delphiniums, should have at least a few flowers fully open before they are cut; flowers of the daisy family won’t continue to open if they are not fully open before they are cut.
If flowers are cut for a one-time display at a special event, they can be cut at whatever stage is desired.
When flowers are first cut, plunging them into deep, cool water up to their necks lowers the temperature of the stems and petals, crisps the flowers and slows dehydration and decay. The life of most flowers can be lengthened significantly if, before arranging, they are conditioned in a refrigerator or cooler with a temperature of 38-40 degrees for six or more hours.
After arranging the flowers, the water should be six inches or less deep so there is unimpeded air circulation among the stems. Here, too, there are exceptions. Astilbes can last 12 days instead of two to four if they are placed in hot water first, allowed to cool, and then refrigerated.
Good sanitation — of buckets, pruners, and water — cuts down on the growth of bacteria, which plug the stem ends, preventing the uptake of water, and the flowers die of thirst. Commercial cut-flower preservatives prevent bacteria from growing and extend the life of bouquets up to 75 percent when used in the proportions given on product labels.
The University of California has also developed recipes for two cut-flower preservatives. They are:
1. 1 part lemon-lime soda, 3 parts water, and quarter teaspoon bleach per quart
2. 2 tablespoons lemon juice or bottled “Real Lemon,” 1 teaspoon sugar, quarter teaspoon bleach, 9 parts water.
Not all flowers benefit dramatically and a few are even harmed by the use of preservatives. With daffodils it makes no difference; however, they do last longer in a cool location.
Dr. Armitage, through his research, has determined the special needs, vase life and harvest time for some of the flowers we commonly grow. Examples are:
# Coxcomb — Cut when the crested flower is completely open. Removing the foliage immediately aids the stem in supporting the flower better. Expected vase life is 7-10 days.
# China aster — Harvest as outer petals begin to open, strip foliage off stems, plunge in water with preservative, and place in cool temperature. Expected vase life is 5-7 days.
# Delphinium — Cut when half to three-fourths of the flowers have opened, place in water with preservative immediately, and keep away from any source of ethylene (such as ripening fruit). Expected vase life is 6-8 days.
# Hydrangea — Cut when the flower is completely open, place stems in water immediately. Expected vase life is 7-10 days.
# Lilac — Cut when half or more of the flowers are open, cut stems at an angle to increase surface area for stem uptake of water, remove foliage and place in warm water. Expected vase life is 3-5 days.
# Marigold — The large double African-type last longest. Cut when the flower is fully open. Expected vase life is 10-14 days.
# Ornamental Onion (Allium) — The ones with dense flower heads make the best cut flowers. Cut when half the flowers are open. Expected vase life is 10-14 days.
# Peony — Cut when petals show color, are fluffy and start to open. Place stems in warm water immediately to enhance water uptake. Expected vase life is 5-7 days.
# Rose — Cut in the bud stage (more petals equal shorter life). Short stems stay crisp and tend to have a longer vase life. Hybrid teas last longest. Expected vase life is 5-10 days;
# Snapdragon — Cut when half the flowers on the stem are open. They have no special needs. Expected vase life is 5-8 days.
# Sunflower — Cut when a few petals are open. The best varieties for cutting don’t produce pollen, don’t shed, and live longer in the vase. Expected vase life is 7-10 days.
# Sweet Pea — Cut when 2-3 flowers on the individual stem show color. Shorter stems take up more water, with the ideal length ranging from six to eight inches. Expected vase life is 5-7 days.
# Sweet William — Cut when 10-20 percent of the flowers in the cluster are open. Cool temperatures are needed for the best performance and longest vase life. Expected vase life is 7-10 days.
Knowing when to cut flowers, their conditioning needs, and their expected vase life helps us plan ahead, arrange flowers without worrying that they might not look fresh when needed, and decide which flowers for cutting to plant in our own gardens.
Jeanne Rose is a University of California Master Gardener.