ProCuts or Sunrich series will give me an easy 10 days in the vase in plain water. I also have very hard water which doesn't seem to bother them.

At what stage of opening do you cut and what time of the day. Pro Cuts are a fantastic long lived flower. Ideally, suns should be cut just as the petals are lifting off of the disk and of course, early in the day. Do you remove the foliage? Are your suns a pollened variety?, this will decrease vase life too.
Cheers - Kim - BFFF

The pollen-less hybrid sunflowers I have tried all do well in a vase, lasting close to two weeks in plain water, and the water here is also hard. I've settled on just the ProCut and Sunrich series lately and they do well for me. I think Kim gave you good advice about when to cut, although I haven't had a problem with cutting them at almost any time of day. I strip all except the top two or three leaves.

ThinMan

Thanks for all your replies! I do grow the pro cut sunflowers. I cut them in the afternoon and striped some of the foliage. There was one thing I wondered about though. When I cut my sunflowers....the ground was pretty dry. Do the sunflowers need a deep watering the night before being cut?

I use the pro cut and the sunrich series and cut them into clean plain water and they last a good 7 - 10 days. I havent noticed a difference of cutting after they have been watered or the next day but the timing of cutting during the day does make a difference, try cutting early in the morning, maybe they will do better. Kat

Golden Cheer will last 10-14 days if you recut and change the water.