Not at all uncommon, especially if the plants spent the winter indoors. They need a period of acclimation to get used to the temperature swings from indoor to outdoor. Personally, I would not recommend taking an indoor wintered hydrangea outside until after all possibility of frost has passed and nighttime temperatures have hit an even 50F or higher....around Mother's Day in my area.

Hydrangea macrophylla is extremely prone to late frost damage - it is one of the primary causes for failure to flower. Cut off any permanently damaged tips and dead flowers. Foliage will grow back but you may have sacrificed any additional flowering for this season.

FWIW, hydrangeas in zone 6 are not supposed to bloom in March - unless they are greenhouse grown.

â¢Posted by gardengal48 PNW zone 8 (My Page) on
Sun, Apr 6, 14 at 19:26

Thank you so much for the help. I have these for two years now. During the winter, they stayed on the deck and indoors intermittently. They started to sprout in February and flower buds were shown in March.

I do not mind that they fail to flower this year. I just hope they will survive. I plan to leave the pots outside from now on. The predicted low will always be above freezing.