How to make fresh flowers last longer

Given that my last post was a little bit of a rant against the idea that fresh flowers ought to last forever, I thought it was appropriate to explain some strategies to get your beautiful ephemeral flowers to last as long as they can.  Key ideas: water, location, and choosing the right stems. 

• Water - part of what makes flowers fade is that they can no longer keep pumping water up their stems.  In some cases this is because bacteria enter their transport system and clog it up.  Changing the water in your vase helps reduce the build up of bacteria in the water, gives your stems some clean water to imbibe, and gives your arrangement more time to look hydrated and fresh.  If you recut the stems an inch or so, that's every better! This provides the stem with a fresh opportunity to uptake water.  Make sure to cut at an angle to increase the absorptive surface.  
• Location - if your flowers are in a cool shady spot (always out of direct sunlight when possible) this also elongates their lifespan.  Heat makes molecules move faster (faster bacterial growth in the vase), makes water evaporate (out the vase) and transpire (out the stem) faster, and dries out the ambient air faster (increasing all that water movement).  No good for flowers that recently had their lifeline severed. Even if the plants want full sun, flowers never do!  If you have a cool fridge (no ripening veggies or fruit though as ethylene gas can make flowers fade FAST) and can put the arrangement inside overnight with PLENTY of water that will help.  That rule applies best to cool season flowers because if you have zinnias or basil stems in an arrangement cool fridge temps will make them wilt and brown.  
• Choosing the right stems - some flowers naturally have a longer vase life than others.  Hellebores picked at the mature stage will last weeks.  Pineapple Lily (Eucomis) stems will easily last a month!  Ranunculus, stock, and dianthus/carnations also have great longevity.  Other flowers just don't.  Icelandic poppies, dahlias, garden roses, and other much beloved stems just don't last very long.  These can still be fantastic for an event but if you get more than 4 days of vase life, consider yourself lucky.  

If you are getting an arrangement from a local grower it's helpful to let them know if you are going for "Wow" or longevity and they can choose stems better able to meet your wishes.  In the arrangement above, I purposefully chose some flowers that would last a long time (hellebores, ranunculus in the "marshmallow" stage, dianthus and stock), mixed with some "Wow" flowers (Iceland Poppies and some more open tulips) to keep the arrangement changing.  Don't be afraid to pull out flowers as they fade!  Let that also be a reminder to do a fresh cut and water change.  Enjoy your flowers!