Cut flowers don’t need direct sunlight like plants do. Actually, they do much better without the direct heat of the sunlight. The one exception is if the flowers are very tight and you want them to open more quickly, like for a party, where the look of the moment is more important than how long they last.
The heat of the direct sun will cause the flowers to open and mature more quickly.
If you are displaying flowers in sunlight that is unavoidable, make sure they have plenty of water. And if it’s for an event, you could put ice in the water and keep them cooler. They will like that!
Enjoy your flowers this summer! Don’t let the heat stop you from brightening your home or event with their beauty and joy. Let us know what other questions you have, too.