How cold hardy are hydrangeas?
Similarly one may ask, what temperature is too cold for hydrangeas?
Temperatures around 70 degrees Fahrenheit in the day and just below 60 F at night are ideal. During the fall bud development stage, hydrangeas need six weeks of temperatures below 65 F for the buds to set. After this period, the hydrangeas should go dormant in temperatures between 35 and 45 F for six weeks.
- Grandiflora – Creamy white blooms, often called Pee Gee.
- Limelight – Startling lime green flowers.
- Compacta – Great for smaller spaces or containers.
- Pink Diamond – Antique blush blooms.
- Tardiva – Late blooming variety.
- Pinky Winky – Lovely rose pink flowers.
Then, do hydrangeas need to be covered for frost?
Keep Them Cozy. Whether or not hydrangeas need protection depends on how cold the winter temperatures drop. If the air temperature doesn't go below 0 degrees (zone 7) there is no need for winter protection. In colder climates, wrap or completely cover marginally hardy hydrangeas.
Winter Kill on Hydrangeas The low winter temperatures can kill the plant, or they might die because of drying out caused by winds. Because hydrangeas go dormant during the winter, you may not notice winter kill on hydrangeas until spring.