Customers often ask how long their flowers will last at home. The answers lie in a number of factors- many that we can work to control. Ultimately, we are trying to slow decay when we're working with cut flowers.
The flower harvester has the first hand in determining how long the flowers will last. While vase life varies from flower to flower - even when all the best practices are in place - there are some things that should (and should not be done) at harvest time.
To start, flowers should be cut when they are most hydrated - in the early morning or evening. They are more vulnerable to wilting mid-day.
Each flower variety has a preferred harvest stage. Some flowers can be harvested in bud stage. They'll open over time for the customer. Snapdragons can be cut when just one or two blooms on a stalk are open. The remaining buds will grow and bloom, sometimes for as long as two weeks after cutting with proper post-harvest care. Dahlias, on the other hand, will not bloom if cut in bud stage. They need to be cut after the flower has opened, but before the back petals start to dry. I still cut the buds for design work, though. Laceflowers must be cut fully open, after they have transformed from a cup-shape to a soft dome. If cut too early, they droop quickly. Zinnias should be given the pre-cut "wiggle test." You want the stem to seem stiff when you hold it between 6 and 10 inches below the head of the flower and wiggle it gently. If the flower head bobbles, it isn't ready to be harvested yet. For a quick guide to optimal harvest times for many varieties of cut flowers, click here and scroll to page 2.
Next, each variety should be provided with the nutrients that it requires. Some plants need help to absorb the water you put them in. branches can be cross-cut vertically or at a steep slant to improve post-harvest hydration. They can also be treated with a pre-hydration solution (like Easy Dip or Quick Dip) to aid water absorption. Other flowers (yarrow, rudbeckia, zinnia) are considered "dirty flowers" because they seem to dirty up the water quickly. These flowers need an extra solution or a little chlorine tablet to help limit bacteria growth and improve water clarity. Foral hydration products are important for helping flowers like dahlias look their best and last longer. This article from the University of Massachusetts, Amherst Extension is an especially nice guide to pre- and post harvest care for cut flowers. It goes into much greater detail about the ideas I'm sharing in this post.
Then, flowers need time to rest before they are used for design work. This stage is called conditioning. A minimum of a few hours should be provided. I prefer to use flowers that have rested overnight. Most farmers' market flowers are cut the day before we go to market. Wedding and event flowers are cut one or two days before each event, depending on the schedule for design work. Most of our flowers spend their conditioning time in our walk-in cooler. However, some varieties (zinnias, for example) do not like it in there! They prefer to hangout in their buckets in the studio.
So- those steps are all in the hands of your flower farmer. But what can you do at home?
Begin with a very clean vase. As a rule of thumb, I try to only use vessels that I can reach my hand into for washing out with warm soapy water. Once you have your clean vase, add cool clean water, flower food if you have some (now available in take-home packets to our market customers), and your flowers- after you've re-cut the stems to your desired length. Re-cutting the stems aids in water absorption because in doing so, you remove the bacterial plug that has started to form and move up the stem. The only way to get rid of it, is to cut it off and "clear the straw" if you will. Make sure there are no leaves touching the water. Remove any lower hanging leaves from the stems and discard them.
Place your flowers in a cool spot, out of direct sunlight that might warm the water and aid in bacteria growth. It's also important to keep cut flowers away from ripening fruit, so chose a place away from the pretty bowl of fruit on the counter. If your arrangement is small - like a bouquet of sweet peas, I recommend slipping it into the refrigerator at night. If you're not going to see it anyways, you might as well give it a nice chill, right?
Repeat the stem trimming and vase cleaning process and add new water every other day. Remove individual flowers as they decay to protect the remaining ones from following suit right away.
And lastly- enjoy your flowers! I hope the advice above was helpful. It may seem tedious, but with just a few extra moments of care, your flowers can last much longer. For a monthly collection of flower gardening and arranging tips, subscribe to my newsletter and share in the journey of our little flower farm and design studio in the Adirondacks.