Sometimes the flowers won't last and it's not your fault. If the flowers have been cut too late they will tend to wilt quickly, anyway.
You could look at this situation as an opportunity to make some pretty dried flowers.
Some florists recommend that to help the hydrangea stems take up more water and make the flowers last longer, that you gently smash the ends with a hammer; this may literally open up the water-bearing vessels.
As with all cut flowers, the optimal thing to do may be to cut the stems again under water, at a slight angle (so that they don't sit flat on the bottom of the vase). Cut at least 2-3 inches up from the pre-existing cut, and keep them under water thereafter.
Alternatively, dip the stems in alum powder (a mild preservative, available in some florists) before arranging them in a vase.
Also, before placing in a vase, remove as many leaves as possible, add any recommended flower feeders to the water as directed, and touch the petals themselves as little as possible (to avoid possible damage).
The sap from hydrangea stems can be harmful to other flowers, in which case the ends should be cauterized before arranging with the other sensitive species.
You could look at this situation as an opportunity to make some pretty dried flowers.
Some florists recommend that to help the hydrangea stems take up more water and make the flowers last longer, that you gently smash the ends with a hammer; this may literally open up the water-bearing vessels.
As with all cut flowers, the optimal thing to do may be to cut the stems again under water, at a slight angle (so that they don't sit flat on the bottom of the vase). Cut at least 2-3 inches up from the pre-existing cut, and keep them under water thereafter.
Alternatively, dip the stems in alum powder (a mild preservative, available in some florists) before arranging them in a vase.
Also, before placing in a vase, remove as many leaves as possible, add any recommended flower feeders to the water as directed, and touch the petals themselves as little as possible (to avoid possible damage).
The sap from hydrangea stems can be harmful to other flowers, in which case the ends should be cauterized before arranging with the other sensitive species.